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Lehmann MM, Diao H, Ouyang S, Gessler A. Different responses of oxygen and hydrogen isotopes in leaf and tree-ring organic matter to lethal soil drought. Tree Physiol 2024:tpae043. [PMID: 38618738 DOI: 10.1093/treephys/tpae043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 03/02/2024] [Accepted: 04/04/2024] [Indexed: 04/16/2024]
Abstract
The oxygen and hydrogen isotopic composition (δ18O, δ2H) of plant tissues are key tools for the reconstruction of hydrological and plant physiological processes and may therefore be used for disentangling reasons of tree mortality. However, how both elements respond to soil drought conditions before death have rarely been investigated. To test this, we performed a greenhouse study and determined predisposing fertilization and lethal soil drought effects on δ18O and δ2H values of organic matter (OM) in leaves and tree rings of living and dead saplings of five European tree species. For mechanistic insights, we additionally measured isotopic (i.e., δ18O and δ2H values of leaf and twig water), physiological (i.e., leaf water potential and gas-exchange) and metabolic traits (i.e., leaf and stem non-structural carbohydrate concentration, C:N ratios). Across all species, lethal soil drought generally caused a homogenous 2H-enrichment in leaf and tree-ring OM, but a low and heterogenous δ18O response in the same tissues. Unlike δ18O values, δ2H values of tree-ring OM were correlated with those of leaf and twig water and with plant physiological traits across treatments and species. The 2H-enrichment in plant OM also went along with a decrease in stem starch concentrations under soil drought compared to well-watered conditions. In contrast, the predisposing fertilization had generally no significant effect on any tested isotopic, physiological, and metabolic traits. We propose that the 2H-enrichment in the dead trees is related to (i) the plant water isotopic composition, (ii) metabolic processes shaping leaf non-structural carbohydrates, (iii) the use of carbon reserves for growth, and (iv) species-specific physiological adjustments. The homogenous stress imprint on δ2H but not on δ18O suggests that the former could be used as a proxy to reconstruct soil droughts and underlying processes of tree mortality.
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Affiliation(s)
- Marco M Lehmann
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Haoyu Diao
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Shengnan Ouyang
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Institute for Forest Resources and Environment of Guizhou, Guizhou University, Guiyang 550025, China
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
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2
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Bains W, Petkowski JJ, Seager S. Venus' Atmospheric Chemistry and Cloud Characteristics Are Compatible with Venusian Life. Astrobiology 2024; 24:371-385. [PMID: 37306952 DOI: 10.1089/ast.2022.0113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Venus is Earth's sister planet, with similar mass and density but an uninhabitably hot surface, an atmosphere with a water activity 50-100 times lower than anywhere on Earths' surface, and clouds believed to be made of concentrated sulfuric acid. These features have been taken to imply that the chances of finding life on Venus are vanishingly small, with several authors describing Venus' clouds as "uninhabitable," and that apparent signs of life there must therefore be abiotic, or artefactual. In this article, we argue that although many features of Venus can rule out the possibility that Earth life could live there, none rule out the possibility of all life based on what we know of the physical principle of life on Earth. Specifically, there is abundant energy, the energy requirements for retaining water and capturing hydrogen atoms to build biomass are not excessive, defenses against sulfuric acid are conceivable and have terrestrial precedent, and the speculative possibility that life uses concentrated sulfuric acid as a solvent instead of water remains. Metals are likely to be available in limited supply, and the radiation environment is benign. The clouds can support a biomass that could readily be detectable by future astrobiology-focused space missions from its impact on the atmosphere. Although we consider the prospects for finding life on Venus to be speculative, they are not absent. The scientific reward from finding life in such an un-Earthlike environment justifies considering how observations and missions should be designed to be capable of detecting life if it is there.
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Affiliation(s)
- William Bains
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- School of Physics and Astronomy, Cardiff University, Cardiff, United Kingdom
| | - Janusz J Petkowski
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- JJ Scientific, Warsaw, Poland
| | - Sara Seager
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Tripathi IM, Mahto SS, Kushwaha AP, Kumar R, Tiwari AD, Sahu BK, Jain V, Mohapatra PK. Dominance of soil moisture over aridity in explaining vegetation greenness across global drylands. Sci Total Environ 2024; 917:170482. [PMID: 38296067 DOI: 10.1016/j.scitotenv.2024.170482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 01/16/2024] [Accepted: 01/24/2024] [Indexed: 02/04/2024]
Abstract
Drylands are one of the most sensitive areas to climate change. Despite being characterized by water scarcity and low precipitation, drylands support a wide range of green biodiversity and nearly 40 % of the global population. However, the climate change impacts on dryland characteristics and vegetation dynamics are debatable as the reasons remain poorly understood. Here, we use hydro-meteorological variables from ERA5 reanalysis and GIMMS-NDVI to analyze the changes in dryland aridity and vegetation greenness in the eight selected global dryland regions. The total dryland area (excluding hyperarid) has increased by 12 %, while arid, semiarid, and dry sub-humid areas have increased by 10.5 %, 8 %, and 25 %, respectively. We find a significant increase in aridity in drylands across the globe, except for South Asia. A decrease (increase) in precipitation is the major driver for a significant increase (decrease) in dryland aridity, with a notable contribution from climate warming. Despite decreasing trends in precipitation, vegetation greenness has significantly increased in most dryland regions due to increased soil moisture. Cropland expansion in Europe, Asia, and Australia resulted in the maximum increase in NDVI (Normalized Difference Vegetation Index) in dryland regions. The highest increase, with a ΔNDVI of 0.075, was observed in South Asia. The enhanced vegetation greenness observed is attributed to the expansion of croplands in recent decades, which has increased soil moisture. Overall, we show that monitoring soil moisture variability can provide a more robust explanation for vegetation greenness in the global drylands than aridity change. Moreover, human interventions of climatic alteration through land use change practices, such as cropland expansion, cannot be ignored while explaining the ecosystem dynamics of the drylands.
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Affiliation(s)
- Indra Mani Tripathi
- Department of Earth Sciences, Indian Institute of Technology (IIT) Gandhinagar, India.
| | - Shanti Shwarup Mahto
- Department of Earth Sciences, Indian Institute of Technology (IIT) Gandhinagar, India
| | - Anuj Prakash Kushwaha
- Department of Earth Sciences, Indian Institute of Technology (IIT) Gandhinagar, India
| | - Rahul Kumar
- Department of Civil, Environmental and Geomatics Engineering, Florida Atlantic University, USA
| | - Amar Deep Tiwari
- Department of Civil and Environmental Engineering, Michigan State University, USA
| | - Bidhan Kumar Sahu
- Department of Civil Engineering, Indian Institute of Technology (IIT) Gandhinagar, India
| | - Vikrant Jain
- Department of Earth Sciences, Indian Institute of Technology (IIT) Gandhinagar, India
| | - Pranab Kumar Mohapatra
- Department of Civil Engineering, Indian Institute of Technology (IIT) Gandhinagar, India
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4
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Luo C, Fang Z, Liu J, Han F, Wu Y, Bing H, Zhao P. Root carbon and soil temperature may be key drivers of below-ground biomass in grassland following prescribed fires in autumn and spring. J Environ Manage 2024; 349:119337. [PMID: 37951102 DOI: 10.1016/j.jenvman.2023.119337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 11/13/2023]
Abstract
Under global warming, fire and the season in which the fire occurs both have important impacts on grassland plant biomass. Still, the effect of fire on below-ground biomass (BB) along a natural aridity gradient and the main impact factors remain unclear. Here, we conducted a fire manipulation experiment (including un-fired, autumn fire and spring fire treatments) to investigate the effects of prescribed fire on BB and its critical determinants along a transect of grassland in northern China. BB had different response strategies in different aridity regions and fire seasons, despite above-ground biomass (AB) and root-shoot ratio were not significantly affected by fire. General linear regression models revealed that the fire changed the trend of increasing BB to decreasing along increasing aridity (p < 0.05). Random forest model (RFM) and partial correlations revealed that the BB was primarily influenced by aridity, followed by the nitrogen (N) and phosphorus (P) concentration ratio of AB under un-fired disturbance. For autumn fire, the BB was primarily influenced by below-ground biomass carbon concentration (BB c), followed by the C and N concentration ratio of BB. For spring fire, the BB was primarily influenced by soil temperature (ST), followed by aridity and soil total phosphorus concentration (Soil p). Furthermore, partial least squares path model (PLS-PM) revealed that autumn fires weakened the effects of environmental factors on BB, while spring fires enhanced the effects of soil nutrients on BB. These suggested that fire disrupted the original stable nutrient dynamics of BB. Our results suggested that fire promoted the growth of BB in relatively humid areas (aridity = 0.51-0.53) while inhibited the growth of BB in relatively arid areas (aridity = 0.68-0.74). BB c and ST may be key drivers of BB after prescribed fire in autumn and spring.
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Affiliation(s)
- Chaoyi Luo
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China; Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610299, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhao Fang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China
| | - Jiang Liu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China
| | - Fengpeng Han
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China.
| | - Yanhong Wu
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610299, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Haijian Bing
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610299, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Zhao
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610299, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Moreno-de-Las-Heras M, Bochet E, Vicente-Serrano SM, Espigares T, Molina MJ, Monleón V, Nicolau JM, Tormo J, García-Fayos P. Drought conditions, aridity and forest structure control the responses of Iberian holm oak woodlands to extreme droughts: A large-scale remote-sensing exploration in eastern Spain. Sci Total Environ 2023; 901:165887. [PMID: 37517715 DOI: 10.1016/j.scitotenv.2023.165887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
Understanding how Mediterranean forests respond to the increasing frequency of extreme droughts and forest densification is crucial for effective land management in the present context of climate change and land abandonment. We study the responses of Iberian holm oak (Quercus ilex L.) woodlands to recent extreme droughts during 2000-2019 along broad gradients of climate aridity and forest structure. To this purpose, we apply large-scale remote-sensing using MODIS EVI as a primary production proxy in 5274 Q. ilex sites distributed within a 100,000 km2 region in eastern Spain. These woodlands were extensively affected by two extreme drought events in 2005 and 2012. Resistance, assessed as the capacity of the ecosystems to maintain primary production during drought, was significantly lower for semi-arid than for sub-humid and dry-transition conditions. Holm oak woodlands located in semi-arid areas of the region showed also poorer resilience to drought, characterized by low capacity to fully recover to their pre-drought production levels. Further, drought intensity and both pre- and post-drought hydric conditions controlled the variations of resistance, recovery and resilience between the two analyzed extreme drought events. Drought effects were particularly negative for dense Q. ilex stands under semi-arid climate conditions, where strong competition for scarce water resources reduced drought resistance. The observed drought vulnerability of semi-arid holm oak woodlands may affect the long-term stability of these dry forests. Adaptive management strategies, such as selective forest thinning, may be useful for improving drought responses in these more vulnerable semi-arid woodlands. Conversely, natural rewilding may more appropriately guide management actions for more humid areas, where densely developed Q. ilex woodlands show in general a high ability to maintain ecosystem primary production during drought.
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Affiliation(s)
- M Moreno-de-Las-Heras
- Mediterranean Environmental Research Group (GRAM), Department of Geography, University of Barcelona, 08001 Barcelona, Spain.
| | - E Bochet
- Desertification Research Center (CIDE, CSIC-UV-GV), 46113 Moncada, Valencia, Spain
| | - S M Vicente-Serrano
- Pyrenean Institute of Ecology (IPE-CSIC), Spanish National Research Council (CSIC), 50059 Zaragoza, Spain
| | - T Espigares
- Department of Life Sciences, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain
| | - M J Molina
- Desertification Research Center (CIDE, CSIC-UV-GV), 46113 Moncada, Valencia, Spain
| | - V Monleón
- US Forest Service Pacific Northwest Research Station, Corvallis, OR 97331, USA
| | - J M Nicolau
- Department of Agrarian and Environmental Sciences, University of Zaragoza, 22071 Huesca, Spain; Environmental Sciences Institute of Aragon, University of Zaragoza, 50009 Zaragoza, Spain
| | - J Tormo
- Department of Agrarian and Environmental Sciences, University of Zaragoza, 22071 Huesca, Spain; Environmental Sciences Institute of Aragon, University of Zaragoza, 50009 Zaragoza, Spain
| | - P García-Fayos
- Desertification Research Center (CIDE, CSIC-UV-GV), 46113 Moncada, Valencia, Spain
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Ameer A, Ahmad F, Asghar N, Hameed M, Ahmad KS, Mehmood A, Nawaz F, Shehzad MA, Mumtaz S, Kaleem M, Iqbal U. Aridity-driven changes in structural and physiological characteristics of Buffel grass ( Cenchrus ciliaris L.) from different ecozones of Punjab Pakistan. Physiol Mol Biol Plants 2023; 29:1205-1224. [PMID: 37829703 PMCID: PMC10564708 DOI: 10.1007/s12298-023-01351-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/04/2023] [Accepted: 08/21/2023] [Indexed: 10/14/2023]
Abstract
Cenchrus ciliaris L. is a perennial grass that can grow in a diverse range of habitats including challenging deserts. The purpose of the study was to investigate the impact of aridity on morpho-anatomical and physiological traits in C. ciliaris populations collected from arid and semi-arid areas of Punjab, Pakistan. The populations growing in extremely arid conditions displayed a range of structural and physiological adaptations. Under extremely dry conditions, root epidermal thickness (90.29 µm), cortical cell area (7677.78 µm2), and metaxylem cell area (11,884.79 µm2) increased while root pith cell area (2681.96 µm2) decreased in tolerant populations. The populations under extremely aridity maximized leaf lamina (184.21 µm) and midrib thickness (316.46 µm). Additionally, highly tolerant populations were characterized by the accumulation of organic osmolytes such as glycinebetaine (132.60 µmol g-1 FW) was increased in QN poulations, proline (118.01 µmol g-1 F.W) was maximum in DF populations, and total amino acids (69.90 mg g-1 FW) under extreme water deficit conditions. In arid conditions, abaxial stomatal density (2630.21 µm) and stomatal area (8 per mm2) were also reduced in DF populations to check water loss through transpiration. These findings suggest that various parameters are crucial for the survival of C. ciliaris in arid environments. The main strategies used by C. ciliaris was intensive sclerification, effective retention of ions, and osmotic adjustment through proline and glycinebetaine under arid conditions. Supplementary Information The online version contains supplementary material available at 10.1007/s12298-023-01351-3.
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Affiliation(s)
- Amina Ameer
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, 38000 Pakistan
| | - Farooq Ahmad
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, 38000 Pakistan
| | - Naila Asghar
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, 38000 Pakistan
| | - Mansoor Hameed
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, 38000 Pakistan
| | | | - Ansar Mehmood
- Department of Botany, University of Poonch Rawalakot, Rawalakot, 12350 AJK Pakistan
| | - Fahim Nawaz
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Muhammad Asif Shehzad
- Institute of Plant Breeding and Biotechnology, MNS University of Agriculture, Multan, 66000 Pakistan
| | - Sahar Mumtaz
- Division of Science and Technology, Department of Botany, University of Education, Lahore, 54770 Pakistan
| | - Muhammad Kaleem
- Department of Botany, University of Agriculture Faisalabad, Faisalabad, 38000 Pakistan
| | - Ummar Iqbal
- Department of Botany, The Islamia University of Bahawalpur, Rahim Yar Khan Campus, Bahawalpur, 64200 Pakistan
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Portela AP, Durance I, Vieira C, Honrado J. Response-effect trait overlap and correlation in riparian plant communities suggests sensitivity of ecosystem functioning and services to environmental change. Sci Total Environ 2023; 860:160549. [PMID: 36455733 DOI: 10.1016/j.scitotenv.2022.160549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Environmental changes and biodiversity loss have emphasized the need to understand how communities affect ecosystem functioning and services. In riparian ecosystems, integrative, generalizable, broad-scale models of ecosystem functioning are still required to fulfill this need. However, few studies have explored the links between functional traits, ecosystem functions, and the services of riparian vegetation. Here we adapt the response-effect trait framework to link drivers, traits, ecosystem functions, and services in riparian ecosystems and assess ecosystem functioning sensitivity to environmental changes. The response-effect trait framework distinguishes between traits related to responses to the environment (response traits) and effects on ecosystem functioning (effect traits). The framework predicts that if response and effect traits are tightly linked, shifts in environmental drivers may alter communities' traits and ecosystem functioning. We adapted the response-effect trait framework for riparian plant communities and used it to assess the overlap between response and effect traits. We tested for correlation among traits identified in the framework and for community functional responses to climatic, topographic, soil, and land cover factors using riparian plant communities along a Temperate-Mediterranean climate gradient in North Portugal. We found a high overlap between response and effect traits, with seven out of thirteen traits identified as both response and effect. Additionally, we found trait linkages in four groups of positively correlated community mean traits. Precipitation and aridity were the most predictive drivers of community functional structure, and life form and leaf area were the most responsive traits. Overall, our findings suggest riparian plant communities are likely to propagate the effects of environmental changes to ecosystem functioning and services, affecting several regulation ecosystem services. This work highlights the sensitivity of riparian ecosystems to environmental changes and how it can affect ecosystem services. Similar functional approaches can be useful for adaptive ecosystem management to sustain biodiversity and ecosystem services.
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Affiliation(s)
- Ana Paula Portela
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal; BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal.
| | - Isabelle Durance
- Water Research Institute and School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Cristiana Vieira
- Museu de História Natural e da Ciência da Universidade do Porto (MHNC-UP/UPorto/PRISC), Praça Gomes Teixeira, 4099-002 Porto, Portugal
| | - João Honrado
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal; BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
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Hu B, Wu H, Han H, Cheng X, Kang F. Dramatic shift in the drivers of ecosystem service trade-offs across an aridity gradient: Evidence from China's Loess Plateau. Sci Total Environ 2023; 858:159836. [PMID: 36349631 DOI: 10.1016/j.scitotenv.2022.159836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Increased aridity creates challenges for sustainable ecosystem management due to the potential for trade-offs among ecosystem services. However, our understanding of how ecosystem service trade-offs (EST) respond to aridification remains limited. Here, generalized additive models and structural equation modeling were used to explore EST dynamics within an aridity gradient on the Loess Plateau, China. Trade-offs between water yield and both carbon storage and habitat quality showed nonlinear relationships with aridity, first increasing and then decreasing. Interestingly, climatic and human factors mostly indirectly influenced EST via effects on landscape characteristics. In regions with an Aridity Index (AI) value of <0.5, climatic and human factors strongly drove EST; in regions with AI > 0.5, landscape characteristics were most important. Therefore, landscape characteristics acted as the key regulators of EST. Importantly, AI values of ∼0.5 represented a transition point, after which dramatic shifts in EST-driver relationships were observed. As >22 % of the Earth's terrestrial surface is projected to reach this level of aridity by 2100, further research on this boundary (between sub-humid and semi-arid areas) is urgently needed to protect ecosystems from the effects of increasing aridity. This study may serve as a valuable reference for mitigating the potential negative effects of increased aridity on human well-being.
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Affiliation(s)
- Baoan Hu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; Qilaotu mountain National Observation and Research Station of Chinese Forest Ecosystem, Chifeng 024400, China
| | - Huifeng Wu
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; Qilaotu mountain National Observation and Research Station of Chinese Forest Ecosystem, Chifeng 024400, China
| | - Hairong Han
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; Qilaotu mountain National Observation and Research Station of Chinese Forest Ecosystem, Chifeng 024400, China.
| | - Xiaoqin Cheng
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; Qilaotu mountain National Observation and Research Station of Chinese Forest Ecosystem, Chifeng 024400, China
| | - Fengfeng Kang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; Qilaotu mountain National Observation and Research Station of Chinese Forest Ecosystem, Chifeng 024400, China
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Tsakalos JL, Ottaviani G, Chelli S, Rea A, Elder S, Dobrowolski MP, Mucina L. Plant clonality in a soil-impoverished open ecosystem: insights from southwest Australian shrublands. Ann Bot 2022; 130:981-990. [PMID: 36282998 PMCID: PMC9851296 DOI: 10.1093/aob/mcac131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/22/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND AIMS Clonality is a key life-history strategy promoting on-spot persistence, space occupancy, resprouting after disturbance, and resource storage, sharing and foraging. These functions provided by clonality can be advantageous under different environmental conditions, including resource-paucity and fire-proneness, which define most mediterranean-type open ecosystems, such as southwest Australian shrublands. Studying clonality-environment links in underexplored mediterranean shrublands could therefore deepen our understanding of the role played by this essential strategy in open ecosystems globally. METHODS We created a new dataset including 463 species, six traits related to clonal growth organs (CGOs; lignotubers, herbaceous and woody rhizomes, stolons, tubers, stem fragments), and edaphic predictors of soil water availability, nitrogen (N) and phosphorus (P) from 138 plots. Within two shrubland communities, we explored multivariate clonal patterns and how the diversity of CGOs, and abundance-weighted and unweighted proportions .of clonality in plots changed along with the edaphic gradients. KEY RESULTS We found clonality in 65 % of species; the most frequent were those with lignotubers (28 %) and herbaceous rhizomes (26 %). In multivariate space, plots clustered into two groups, one distinguished by sandy plots and plants with CGOs, the other by clayey plots and non-clonal species. CGO diversity did not vary along the edaphic gradients (only marginally with water availability). The abundance-weighted proportion of clonal species increased with N and decreased with P and water availability, yet these results were CGO-specific. We revealed almost no relationships for unweighted clonality. CONCLUSIONS Clonality is more widespread in shrublands than previously thought, and distinct plant communities are distinguished by specific suites (or lack) of CGOs. We show that weighting belowground traits by aboveground abundance affects the results, with implications for trait-based ecologists using abundance-weighting. We suggest unweighted approaches for belowground organs in open ecosystems until belowground abundance is quantifiable.
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Affiliation(s)
- James L Tsakalos
- School of Biosciences and Veterinary Medicine, Plant Diversity and Ecosystems Management Unit, University of Camerino, Camerino, MC, Italy
- Harry Butler Institute, Murdoch University, Murdoch, Perth, WA, Australia
| | - Gianluigi Ottaviani
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Institute of Botany, The Czech Academy of Sciences, Třeboň, Czech Republic
| | - Stefano Chelli
- School of Biosciences and Veterinary Medicine, Plant Diversity and Ecosystems Management Unit, University of Camerino, Camerino, MC, Italy
| | - Alethea Rea
- Harry Butler Institute, Murdoch University, Murdoch, Perth, WA, Australia
| | - Scott Elder
- Harry Butler Institute, Murdoch University, Murdoch, Perth, WA, Australia
| | - Mark P Dobrowolski
- Harry Butler Institute, Murdoch University, Murdoch, Perth, WA, Australia
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
- Iluka Resources Ltd, Perth, WA, Western Australia, Australia
| | - Ladislav Mucina
- Harry Butler Institute, Murdoch University, Murdoch, Perth, WA, Australia
- Department of Geography and Environmental Studies, Centre for Geographic Analysis, Stellenbosch University, Matieland, Stellenbosch, South Africa
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10
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Hidalgo-Galvez MD, Barkaoui K, Volaire F, Matías L, Cambrollé J, Fernández-Rebollo P, Carbonero MD, Pérez-Ramos IM. Can trees buffer the impact of climate change on pasture production and digestibility of Mediterranean dehesas? Sci Total Environ 2022; 835:155535. [PMID: 35489515 DOI: 10.1016/j.scitotenv.2022.155535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/11/2022] [Accepted: 04/22/2022] [Indexed: 06/14/2023]
Abstract
Sustainability and functioning of silvopastoral ecosystems are being threatened by the forecasted warmer and drier environments in the Mediterranean region. Scattered trees of these ecosystems could potentially mitigate the impact of climate change on herbaceous plant community but this issue has not yet tested experimentally. We carried out a field manipulative experiment of increased temperature (+2-3 °C) using Open Top Chambers and rainfall reduction (30%) through rain-exclusion shelters to evaluate how net primary productivity and digestibility respond to climate change over three consecutive years, and to test whether scattered trees could buffer the effects of higher aridity in Mediterranean dehesas. First, we observed that herbaceous communities located beneath tree canopy were less productive (351 g/m2) than in open grassland (493 g/m2) but had a higher digestibility (44% and 41%, respectively), likely promoted by tree shade and the higher soil fertility of this habitat. Second, both habitats responded similarly to climate change in terms of net primary productivity, with a 33% increase under warming and a 13% decrease under reduced rainfall. In contrast, biomass digestibility decreased under increased temperatures (-7.5%), since warming enhanced the fiber and lignin content and decreased the crude protein content of aerial biomass. This warming-induced effect on biomass digestibility only occurred in open grasslands, suggesting a buffering role of trees in mitigating the impact of climate change. Third, warming did not only affect these ecosystem processes in a direct way but also indirectly via changes in plant functional composition. Our findings suggest that climate change will alter both the quantity and quality of pasture production, with expected warmer conditions increasing net primary productivity but at the expense of reducing digestibility. This negative effect of warming on digestibility might be mitigated by scattered trees, highlighting the importance of implementing strategies and suitable management to control tree density in these ecosystems.
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Affiliation(s)
- Maria Dolores Hidalgo-Galvez
- Institute of Natural Resources and Agrobiology of Sevilla (IRNAS-CSIC), 10 Reina Mercedes Avenue, 41012 Seville, Spain; Integrated Biology Doctoral Program, University of Seville, 6 Reina Mercedes Avenue, 41012 Seville, Spain.
| | - Karim Barkaoui
- CIRAD, UMR ABSys, F-34398 Montpellier, France; ABSys, University of Montpellier, CIHEAM-IAMM, CIRAD, INRAE, Institut Agro, Montpellier, France.
| | - Florence Volaire
- Centre d'Écologie Fontionnelle et Évolutive de Montpellier (CEFE-CNRS), 1919 Route de Mende, 34293 Montpellier cedex 5, France.
| | - Luis Matías
- Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, 6 Reina Mercedes Avenue, 41012 Seville, Spain.
| | - Jesús Cambrollé
- Department of Plant Biology and Ecology, Faculty of Biology, University of Seville, 6 Reina Mercedes Avenue, 41012 Seville, Spain.
| | - Pilar Fernández-Rebollo
- Department of Forestry Engineering ETSIAM, School of Agricultural and Forestry Engineering ETSIAM, University of Córdoba, 14071 Córdoba, Spain.
| | - Maria Dolores Carbonero
- Department of Agricultural Production, Institute of Agricultural and Fishing Research and Education (IFAPA), km. 15, El Viso Road, 14270 Hinojosa del Duque, Córdoba, Spain.
| | - Ignacio Manuel Pérez-Ramos
- Institute of Natural Resources and Agrobiology of Sevilla (IRNAS-CSIC), 10 Reina Mercedes Avenue, 41012 Seville, Spain.
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11
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Ombadi M, Varadharajan C. Urbanization and aridity mediate distinct salinity response to floods in rivers and streams across the contiguous United States. Water Res 2022; 220:118664. [PMID: 35671686 DOI: 10.1016/j.watres.2022.118664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/22/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Salinity is an important water quality parameter that affects ecosystem health and the use of freshwaters for industrial, agricultural, and other beneficial purposes. Although a number of studies have investigated the variability and trends of salinity in rivers and streams, the effects of floods on salinity across a wide range of watersheds have not been determined. Here, we examine this question by utilizing long-term observational records of daily streamflow and specific conductance (SC; a proxy for salinity) in addition to catchment characteristics for 259 United States Geological Survey (USGS) monitoring sites in the contiguous United States spanning a wide range of climatic, geologic and hydrologic conditions. We used a combination of statistical methods, random forest machine learning models, and information-theoretic causal inference algorithms to determine the response of SC to floods and the factors that impact salinity changes within sites (intra-site variability) and across sites (inter-site variability). Our results show that changes to SC during flood events exhibited substantial variability ranging from a 100% decrease to 34% increase relative to the long-term mean. We found that dilution is the prevailing mechanism that decreases SC levels during floods for most sites, but other mechanisms caused an increase of SC for 6.1% (n = 5521) of flood events. Our analysis revealed that antecedent conditions of SC in the few days preceding the flood are the most important factor in explaining intra-site variability. The response of salinity to floods also varied considerably across sites with different characteristics, with a notable effect of urbanization in temperate climates resulting in increased dilution of SC, and mining in arid climates, which adversely increases SC levels. Overall, we find that the combined effect of aridity and anthropogenic factors is of primary importance in determining how salinity responds to floods, and it bears strongly on water quality conditions in a future world - one in which floods are expected to increase in frequency and intensity, concurrent with shifting aridity patterns and increasing urbanization.
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Affiliation(s)
- Mohammed Ombadi
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA.
| | - Charuleka Varadharajan
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA
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12
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Kinard S, Patrick CJ, Carvallo F. Effects of a natural precipitation gradient on fish and macroinvertebrate assemblages in coastal streams. PeerJ 2021; 9:e12137. [PMID: 34703662 PMCID: PMC8489409 DOI: 10.7717/peerj.12137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 08/18/2021] [Indexed: 11/20/2022] Open
Abstract
Anthropogenic climate change is expected to increase the aridity of many regions of the world. Surface water ecosystems are particularly vulnerable to changes in the water-cycle and may suffer adverse impacts in affected regions. To enhance our understanding of how freshwater communities will respond to predicted shifts in water-cycle dynamics, we employed a space for time approach along a natural precipitation gradient on the Texas Coastal Prairie. In the spring of 2017, we conducted surveys of 10 USGS-gauged, wadeable streams spanning a semi-arid to sub-humid rainfall gradient; we measured nutrients, water chemistry, habitat characteristics, benthic macroinvertebrates, and fish communities. Fish diversity correlated positively with precipitation and was negatively correlated with conductivity. Macroinvertebrate diversity peaked within the middle of the gradient. Semi-arid fish and invertebrate communities were dominated by euryhaline and live-bearing taxa. Sub-humid communities contained environmentally sensitive trichopterans and ephemeropterans as well as a variety of predatory fish which may impose top-down controls on primary consumers. These results warn that aridification coincides with the loss of competitive and environmentally sensitive taxa which could yield less desirable community states.
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Affiliation(s)
- Sean Kinard
- Department of Biological Sciences, Virginia Institute of Marine Science, Gloucester Point, VA, United States of America
| | - Christopher J Patrick
- Department of Biological Sciences, Virginia Institute of Marine Science, Gloucester Point, VA, United States of America
| | - Fernando Carvallo
- Department of Life Sciences, Texas A&M Corpus Christi, Corpus Christi, TX, United States of America
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13
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Lo S, Parker T, Muñoz-Amatriaín M, Berny-Mier Y Teran JC, Jernstedt J, Close TJ, Gepts P. Genetic, anatomical, and environmental patterns related to pod shattering resistance in domesticated cowpea [Vigna unguiculata (L.) Walp]. J Exp Bot 2021; 72:6219-6229. [PMID: 34106233 DOI: 10.1093/jxb/erab259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/06/2021] [Indexed: 05/27/2023]
Abstract
Pod shattering, which causes the explosive release of seeds from the pod, is one of the main sources of yield losses in cowpea in arid and semi-arid areas. Reduction of shattering has therefore been a primary target for selection during domestication and improvement of cowpea, among other species. Using a mini-core diversity panel of 368 cowpea accessions, four regions with a statistically significant association with pod shattering were identified. Two genes (Vigun03g321100 and Vigun11g100600), involved in cell wall biosynthesis, were identified as strong candidates for pod shattering. Microscopic analysis was conducted on a subset of accessions representing the full spectrum of shattering phenotypes. This analysis indicated that the extent of wall fiber deposition was highly correlated with shattering. The results from this study also demonstrate that pod shattering in cowpea is exacerbated by arid environmental conditions. Finally, using a subset of West African landraces, patterns of historical selection for shattering resistance related to precipitation in the environment of origin were identified. Together, these results shed light on sources of resistance to pod shattering, which will, in turn, improve climate resilience of a major global nutritional staple.
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Affiliation(s)
- Sassoum Lo
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521,USA
- Department of Plant Sciences/MS1, University of California, Davis, CA 95616-8780,USA
| | - Travis Parker
- Department of Plant Sciences/MS1, University of California, Davis, CA 95616-8780,USA
| | - María Muñoz-Amatriaín
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521,USA
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523,USA
| | | | - Judy Jernstedt
- Department of Plant Sciences/MS1, University of California, Davis, CA 95616-8780,USA
| | - Timothy J Close
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521,USA
| | - Paul Gepts
- Department of Plant Sciences/MS1, University of California, Davis, CA 95616-8780,USA
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14
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Salazar Zarzosa P, Diaz Herraiz A, Olmo M, Ruiz-Benito P, Barrón V, Bastias CC, de la Riva EG, Villar R. Linking functional traits with tree growth and forest productivity in Quercus ilex forests along a climatic gradient. Sci Total Environ 2021; 786:147468. [PMID: 33975100 DOI: 10.1016/j.scitotenv.2021.147468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
Plant functional traits are highly plastic to changes in climatic factors and nutrient availability. However, the intraspecific plant response to abiotic factors and the overall effect on tree growth and productivity is still under debate. We studied forest productivity for 30 Quercus ilex subsp. ballota forests in Spain along a broad climatic gradient of aridity (mean annual precipitation from 321 to 858 mm). We used linear mixed models to quantify the effect of climatic and edaphic (soil nutrients, topography, and texture) factors on tree functional traits (leaf and branch traits), and subsequently, the effect of such functional traits and abiotic factors on the relative growth rate (RGR) of adult trees. We used piecewise structural equation models (SEMs) to determine the causal effect of intrinsic and extrinsic factors on forest productivity. Our results showed that tree functional traits were mainly explained by climatic and edaphic factors. Functional traits and tree biomass explained forest biomass and RGR, respectively, which ultimately explained forest productivity. In conclusion, intraspecific variability of functional traits has a significant effect on plant biomass and growth, which ultimately may explain forest productivity in Quercus ilex forests.
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Affiliation(s)
- Pablo Salazar Zarzosa
- Área de Ecología, Facultad de Ciencias, Universidad de Córdoba, Campus de Rabanales, 14071 Córdoba, Spain.
| | - Aurelio Diaz Herraiz
- Área de Ecología, Facultad de Ciencias, Universidad de Córdoba, Campus de Rabanales, 14071 Córdoba, Spain; Instituto Federal de Ciência e Tecnologia do Amazonas, Campus Humaitá, 69800.000, Brazil
| | - Manuel Olmo
- Área de Ecología, Facultad de Ciencias, Universidad de Córdoba, Campus de Rabanales, 14071 Córdoba, Spain
| | - Paloma Ruiz-Benito
- Ecology and Forest Restoration Group, Life Science Department, University of Alcalá, Ctra. Madrid-Barcelona, Km. 33,600, 28805 Alcalá de Henares, Spain; Remote Sensing Research Group, Department of Geology, Geography and Environment, University of Alcalá, Calle Colegios 2, 28801 Alcalá de Henares, Spain
| | - Vidal Barrón
- Departamento de Agronomía, Escuela Técnica Superior de Ingenieros Agrónomos y de Montes, Universidad de Córdoba, Campus de Rabanales, 14071 Córdoba, Spain
| | - Cristina C Bastias
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Univ Paul Valéry Montpellier 3, Montpellier, France; Departamento de Ingeniería Forestal, Escuela Técnica Superior de Ingeniería Agronómica y de Montes, Universidad de Córdoba, Córdoba, Spain
| | - Enrique G de la Riva
- Department of Ecology, Brandenburg University of Technology, 03046 Cottbus, Germany
| | - Rafael Villar
- Área de Ecología, Facultad de Ciencias, Universidad de Córdoba, Campus de Rabanales, 14071 Córdoba, Spain
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15
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Noorisameleh Z, Gough WA, Mirza MMQ. Persistence and spatial-temporal variability of drought severity in Iran. Environ Sci Pollut Res Int 2021; 28:48808-48822. [PMID: 33928509 DOI: 10.1007/s11356-021-14100-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
Drought is a natural hazard that can inflict significant damage to agriculture, society, economy, and ecosystems. The assessment of the persistence of drought severity (PDS) assists in understanding the characteristics of droughts better and enables the development of associated prediction tools and models. This work explores the persistence and spatial-temporal variability of drought severity (DS) in the diverse dryland of Iran. Using monthly precipitation and temperature data of 44 synoptic stations from 1989 to 2018, relationships between DS coefficient of precipitation variation, aridity, and the persistence percentage are determined by the application of the standardized precipitation index (SPI), the dryland index, and the Hurst exponent (H). The results confirm the persistence of droughts in Iran as H exceeded the 0.5 threshold for all stations. The PDS average in Iran is 0.78 with high regional variability reflective of different climatic conditions and geographical locations. An inverse relationship exists between the long-term coefficient of variation of monthly precipitation and PDS in the hyper-arid and arid regions of watersheds. Higher PDS values and increasing trend in the DS are detected in dry-subhumid areas. Also, the effect of the El Niño-Southern Oscillation (ENSO), a teleconnection metric, on the DS displays high spatial and temporal variability in Iran. The results show that the PDS is consistent with the spatial variation of DS changes during the period of 2009-2018.
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Affiliation(s)
- Zahra Noorisameleh
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, M1C 1A4, Canada.
| | - William A Gough
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, M1C 1A4, Canada
| | - M Monirul Qader Mirza
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, M1C 1A4, Canada
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16
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Oyanoghafo OO, O’ Brien C, Choat B, Tissue D, Rymer PD. Vulnerability to xylem cavitation of Hakea species (Proteaceae) from a range of biomes and life histories predicted by climatic niche. Ann Bot 2021; 127:909-918. [PMID: 33606015 PMCID: PMC8225280 DOI: 10.1093/aob/mcab020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND AIMS Extreme drought conditions across the globe are impacting biodiversity, with serious implications for the persistence of native species. However, quantitative data on physiological tolerance are not available for diverse flora to inform conservation management. We quantified physiological resistance to cavitation in the diverse Hakea genus (Proteaceae) to test predictions based on climatic origin, life history and functional traits. METHODS We sampled terminal branches of replicate plants of 16 species in a common garden. Xylem cavitation was induced in branches under varying water potentials (tension) in a centrifuge, and the tension generating 50 % loss of conductivity (stem P50) was characterized as a metric for cavitation resistance. The same branches were used to estimate plant functional traits, including wood density, specific leaf area and Huber value (sap flow area to leaf area ratio). KEY RESULTS There was significant variation in stem P50 among species, which was negatively associated with the species climate origin (rainfall and aridity). Cavitation resistance did not differ among life histories; however, a drought avoidance strategy with terete leaf form and greater Huber value may be important for species to colonize and persist in the arid biome. CONCLUSIONS This study highlights climate (rainfall and aridity), rather than life history and functional traits, as the key predictor of variation in cavitation resistance (stem P50). Rainfall for species origin was the best predictor of cavitation resistance, explaining variation in stem P50, which appears to be a major determinant of species distribution. This study also indicates that stem P50 is an adaptive trait, genetically determined, and hence reliable and robust for predicting species vulnerability to climate change. Our findings will contribute to future prediction of species vulnerability to drought and adaptive management under climate change.
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Affiliation(s)
- Osazee O Oyanoghafo
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2751,Australia
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Benin, Benin City, Nigeria
| | - Corey O’ Brien
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2751,Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2751,Australia
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2751,Australia
| | - Paul D Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2751,Australia
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17
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Herrero J, Castañeda C. Data supporting the soil salinity evolution appraisals in the Flumen irrigation district, NE Spain. Data Brief 2021; 37:107171. [PMID: 34136601 PMCID: PMC8181785 DOI: 10.1016/j.dib.2021.107171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/19/2021] [Accepted: 05/25/2021] [Indexed: 10/31/2022] Open
Abstract
The dataset presented comprises (raw data) scans of the marked paper contact prints from a dedicated photogrammetric flight and a diagram showing the location of each of these photograms. The flight was commissioned specifically for the soil survey presented herein. The scanned paper prints are those used in the field to characterize the soil salinity of 27,500 ha within the Flumen irrigation district, in the semi-arid Central Ebro Basin, in Spain. On these prints, the soil surveyors marked the locations of the sampling sites. IRYDA, the extinct Spanish Ministry of Agriculture agency, in charge of designing and implementing new irrigation districts, commissioned the flight in 1975. These paper prints enabled us to resample the soils years later, to: (i) determine the soil salinity evolution from 1975 to 1985 [1], and from 1975 to 1999 [2]; (ii) apply electromagnetic induction (EMI) [3] for the same purpose; (iii) use multivariate analysis to discriminate the salinity trends from 1975 to 1999 in the different soil units [4]; and (iv) for land evaluation [5]. The report and two volumes of annexes [6], [7], [8], prepared by the contractor INYPSA for IRYDA, contain data on the soluble salts and other soil components sampled in 1975 as well as soil descriptions and agronomical data. The aerial photographs presented herein allow the sites sampled in 1975 to be located. This is the first step in exploiting the legacy data to appraise [9] the effects on the salinity and other soil properties recorded in 1975. The irrigation and the change from basin and border flooding to pressurized techniques, with the merging of many plots, govern these effects.
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Affiliation(s)
- Juan Herrero
- Estación Experimental de Aula Dei, CSIC, Ave. Montañana 1005, 50059 Zaragoza, Spain
| | - Carmen Castañeda
- Estación Experimental de Aula Dei, CSIC, Ave. Montañana 1005, 50059 Zaragoza, Spain
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18
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Wang LQ, Ali A. Climate regulates the functional traits - aboveground biomass relationships at a community-level in forests: A global meta-analysis. Sci Total Environ 2021; 761:143238. [PMID: 33158541 DOI: 10.1016/j.scitotenv.2020.143238] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 05/22/2023]
Abstract
The relationships between plant functional traits and aboveground biomass (AGB) stock have been explored across forest biomes. Yet, meta-analyses synthesizing our understanding regarding the influences of climate and soil on the functional traits - AGB relationships at a community-level in global forests are still unavailable. Here, we evaluated the latitudinal gradient in the functional traits -AGB relationships in forests, including functional trait diversity (FTD) - AGB (FTD-AGB), community-weighted mean (CWM) of conservative traits (CWMCT-AGB), CWM of acquisitive traits (CWMAT-AGB), and CWM of plant maximum height or diameter (FunDom-AGB), and then answer the question whether climate and soil conditions modulate the functional traits - AGB relationships in global forests. To do so, we selected those studies which reported the relationships of FTD and CWM with AGB stock (i.e. in Mg ha-1) rather with AGB productivity or growth (i.e. Mg ha-1 yr-1) at a community-level (i.e. forest plot). By using piecewise structural equation meta-modeling, we found that: (1) functional traits - AGB relationships at a community-level were driven by mean annual temperature (MAT), aridity and soil fertility. (2) Higher MAT and low aridity promoted FTD-AGB relationships but the opposite trend was true for CWMCT-AGB, whereas higher MAT promoted CWMAT-AGB and FunDom-AGB at high aridity levels. (3) The FunDom-AGB relationship increased with increasing the number of forest plots but other relationships declined. (4) The negligible or negative FTD-AGB relationships but the positive AGB-FunDom relationships were conspicuous across global forests, indicating the mass ratio effect in terms of functional dominance. Our meta-analysis suggests that functional dominance and conservative species' strategy in relation to favorable abiotic conditions should be promoted to increase AGB stock under global environmental changes.
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Affiliation(s)
- Li-Qiu Wang
- Department of Forest Resources Management, College of Forestry, Nanjing Forestry University, Nanjing 210037, Jiangsu, China; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Arshad Ali
- Department of Forest Resources Management, College of Forestry, Nanjing Forestry University, Nanjing 210037, Jiangsu, China; Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
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Šmíd J, Uvizl M, Shobrak M, Salim AFA, AlGethami RHM, Algethami AR, Alanazi ASK, Alsubaie SD, Busais S, Carranza S. Swimming through the sands of the Sahara and Arabian deserts: Phylogeny of sandfish skinks (Scincidae, Scincus) reveals a recent and rapid diversification. Mol Phylogenet Evol 2021; 155:107012. [PMID: 33217580 DOI: 10.1016/j.ympev.2020.107012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/05/2020] [Accepted: 11/11/2020] [Indexed: 11/18/2022]
Abstract
Large parts of the Sahara Desert and Arabia are covered by sand seas and sand dunes, which are inhabited by specialized animal communities. For example, many lizards have developed adaptations to life in loose sand, including sand-swimming behavior. The best-known sand swimmers of the Saharo-Arabia are the sandfish skinks (genus Scincus). Although there are currently only four Scincus species recognized, their phylogenetic relationships have not yet been addressed in detail. We use eight genetic markers (three mitochondrial, five nuclear) and a complete sampling of species to infer the relationships within the genus. We employ multiple phylogenetic approaches to reconstruct the evolutionary history of these skinks and to assess the level of reticulation at the onset of their radiation. Our results indicate the presence of five strongly supported species-level lineages, four represented by the currently recognized species and the fifth by S. scincus conirostris, which does not form a clade with S. scincus. Based on these results we elevate the Iranian and northern Arabian S. conirostris to the species level. The two Saharan species, S. albifasciatus and S. scincus, are sister in all analyses. Deeper relationships within the genus, however, remained largely unresolved despite the extensive genetic data set. This basal polytomy, together with the fact that we detected no sign of hybridization in the history of the genus, indicates that the diversification of the five Scincus species was rapid, burst-like, and not followed by secondary hybridization events. Divergence time estimations show a Middle Pliocene crown radiation of the genus (3.3 Mya). We hypothesize that the aridification of the Saharo-Arabia that began in the Late Miocene triggered the initial diversification of Scincus, and that the subsequent expansion of sand deserts enabled their dispersal over the large Saharan and Arabian range. We discuss the evolution of body form in sand swimming lizards and ponder how Scincus retained their fully limbed morphology despite being sand swimmers that are typically limbless.
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Pérez-Martínez C, Rühland KM, Smol JP, Jones VJ, Conde-Porcuna JM. Long-term ecological changes in Mediterranean mountain lakes linked to recent climate change and Saharan dust deposition revealed by diatom analyses. Sci Total Environ 2020; 727:138519. [PMID: 32498206 DOI: 10.1016/j.scitotenv.2020.138519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/13/2020] [Accepted: 04/05/2020] [Indexed: 06/11/2023]
Abstract
Anthropogenic climate change and the recent increase of Saharan dust deposition has had substantial effects on Mediterranean alpine regions. We examined changes in diatom assemblage composition over the past ~180 years from high-resolution, dated sediment cores retrieved from six remote lakes in the Sierra Nevada Mountains of Southern Spain. In all lakes, changes in diatom composition began over a century ago, but were more pronounced after ~1970 CE, concurrent with trends in rising regional air temperature, declining precipitation, and increased Saharan dust deposition. Temperature was identified as the main predictor of diatom assemblage changes, whereas both Saharan dust deposition drivers, the Sahel precipitation index and the winter North Atlantic Oscillation, were secondary explanatory variables. Diatom compositional shifts are indicative of lake alkalinization (linked to heightened evapoconcentration and an increase in calcium-rich Saharan dust input) and reduced lake water turbulence (linked to lower water levels and reduced inflows to the lakes). Moreover, decreases in epiphytic diatom species were indicative of increasing aridity and the drying of catchment meadows. Our results support the conclusions of previous chlorophyll-a and cladoceran-based paleolimnological analyses of these same dated sedimentary records which show a regional-scale response to climate change and Saharan dust deposition in Sierra Nevada lakes and their catchments during the 20th century. However, diatom assemblages seem to respond to different atmospheric and climate-related effects than cladoceran assemblages and chlorophyll-a concentrations. The recent impact of climate change and atmospheric Saharan deposition on lake biota assemblages and water chemistry, as well as catchment water availability, will have important implications for the valuable ecosystem services that the Sierra Nevada provides.
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Affiliation(s)
- Carmen Pérez-Martínez
- Institute of Water Research, University of Granada, 18071 Granada, Spain; Department of Ecology, Faculty of Science, University of Granada, 18071 Granada, Spain.
| | - Kathleen M Rühland
- Paleoecological Environmental Assessment and Research Lab (PEARL), Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada
| | - John P Smol
- Paleoecological Environmental Assessment and Research Lab (PEARL), Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Vivienne J Jones
- Environmental Change Research Centre, Department of Geography, University College London, Pearson Building, Gower Street, London WC1E 6BT, UK
| | - José M Conde-Porcuna
- Institute of Water Research, University of Granada, 18071 Granada, Spain; Department of Ecology, Faculty of Science, University of Granada, 18071 Granada, Spain
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Yan Y, Zhang Q, Buyantuev A, Liu Q, Niu J. Plant functional β diversity is an important mediator of effects of aridity on soil multifunctionality. Sci Total Environ 2020; 726:138529. [PMID: 32305761 DOI: 10.1016/j.scitotenv.2020.138529] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/01/2020] [Accepted: 04/05/2020] [Indexed: 06/11/2023]
Abstract
Previous studies have demonstrated that plant diversity not only plays an important role in maintaining ecosystem functions but can also mediate the impact of climate change on ecosystem functions. However, the relative importance of multiple aspects of diversity at different scales remains unclear. In this study, we investigated species, functional, and phylogenetic aspects of diversity at α and β scales, and measured eight soil functions (aboveground productivity, soil organic carbon, total soil nitrogen, total soil phosphorus, soil available nitrogen, soil available phosphorus, soil carbon-nitrogen ratio, and soil nitrogen-phosphorus ratio) to comprehensively assess the relationship between multiple aspects and scales of plant diversity and soil multifunctionality along an aridity gradient across the grasslands of Inner Mongolia. Diversity at α and β scales explained soil multifunctionality synergistically. Functional diversity explained most of the soil multifunctionality, while phylogenetic diversity explained the least. Aridity had both direct effects on soil multifunctionality, and indirect effects mediated mainly by functional α and β diversity. These findings indicate that in addition to α diversity, β diversity also played an important role in maintaining soil multifunctionality, and was an important mediator for the adverse impact of aridity on soil multifunctionality. Our study highlights the critical role of β diversity, especially regarding functional traits, in predicting the consequences of the increasingly arid conditions in the Inner Mongolian grasslands.
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Affiliation(s)
- Yongzhi Yan
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Qing Zhang
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China.
| | - Alexander Buyantuev
- Department of Geography and Planning, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Qingfu Liu
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Center for Biodiversity Dynamics in a Changing World, Aarhus University, Ny Munkegade114, DK-8000 Aarhus C, Denmark
| | - Jianming Niu
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
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Passarella G, Bruno D, Lay-Ekuakille A, Maggi S, Masciale R, Zaccaria D. Spatial and temporal classification of coastal regions using bioclimatic indices in a Mediterranean environment. Sci Total Environ 2020; 700:134415. [PMID: 31629265 DOI: 10.1016/j.scitotenv.2019.134415] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 06/10/2023]
Abstract
Bioclimatic indices combine atmospheric parameters to provide analytical indication of climatic features and their evolution in space and time that can directly relate with natural resource availability, distribution, and related bio-physical processes. The availability of bioclimatic information can provide natural resource managers with analytical means to assess the magnitude and temporal evolution of drought and climate change parameters that could affect the availability, demand and use of natural resources for various sectors. This paper presents a methodology to process bioclimatic data in the space and time domains for assessing the moisture/dryness level and water requirements of a region, and inform water resource planning and management decisions related to drought, climate variability and change. The methodology relies on a modular assembly of statistical tests and methods, and utilizes point scale measurements of meteorological data to perform the analysis of the spatial behavior of derived bioclimatic indicators at the continuous regional scale, and evaluate the significance of the temporal trends. Also, the article presents an application of the proposed methodology to a coastal area of southern Italy (the Apulia Region) that is characterized by recurring water supply limitations, involving the use of the popular De Martonne bioclimatic aridity index. The methodology allowed to obtain qualitative and quantitative information about the aridity level of the Apulia region, the identification of main bioclimatic zones, and the evaluation of spatial pattern and time evolution of aridity. The determination of bioclimatic zones showed that nearly 40% of the regional territory is characterized by dry sub-humid (Mediterranean) climate, about 30% by sub-humid climate, while nearly 10% and 20% are characterized by semi-arid and humid climates, respectively. The temporal analysis revealed that the Salento and the Ionian coastal zone are areas at risk of increasing aridity, with resulting impacts on the water supply and demand for irrigated agriculture.
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Affiliation(s)
| | - Delia Bruno
- CNR-IIA Institute of Atmospheric Pollution, c/o Unical Polifunzionale, 87036 Rende, Italy
| | - Aimé Lay-Ekuakille
- Department of Innovation Engineering, Università del Salento, Via Monteroni, 73100 Lecce, Italy
| | - Sabino Maggi
- CNR-IIA Institute of Atmospheric Pollution, c/o Interateneo Physics Department, 70125 Bari, Italy
| | - Rita Masciale
- CNR-IRSA Water Research Institute, Via F. De Blasio 5, 70132 Bari, Italy
| | - Daniele Zaccaria
- Department of Land, Air and Water Resources, University of California, Davis, CA, USA
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Boyers M, Parrini F, Owen-Smith N, Erasmus BFN, Hetem RS. How free-ranging ungulates with differing water dependencies cope with seasonal variation in temperature and aridity. Conserv Physiol 2019; 7:coz064. [PMID: 31723430 PMCID: PMC6839429 DOI: 10.1093/conphys/coz064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 07/25/2019] [Accepted: 08/18/2019] [Indexed: 06/01/2023]
Abstract
Large mammals respond to seasonal changes in temperature and precipitation by behavioural and physiological flexibility. These responses are likely to differ between species with differing water dependencies. We used biologgers to contrast the seasonal differences in activity patterns, microclimate selection, distance to potential water source and body temperature of the water-independent gemsbok (Oryx gazella gazella) and water-dependent blue wildebeest (Connochaetes taurinus), free-living in the arid Kalahari region of Botswana. Gemsbok were more active nocturnally during the hot seasons than in the cold-dry season, while wildebeest showed no seasonal difference in their nocturnal activity level. Both species similarly selected shaded microclimates during the heat of the day, particularly during the hot seasons. Wildebeest were further than 10 km from surface water 30% or more of the time, while gemsbok were frequently recorded >20 km from potential water sources. In general, both species showed similar body temperature variation with high maximum 24-h body temperature when conditions were hot and low minimum 24-h body temperatures when conditions were dry, resulting in the largest amplitude of 24-h body temperature rhythm during the hot-dry period. Wildebeest thus coped almost as well as gemsbok with the fairly typical seasonal conditions that occurred during our study period. They do need to access surface water and may travel long distances to do so when local water sources become depleted during drought conditions. Thus, perennial water sources should be provided judiciously and only where essential.
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Affiliation(s)
- Melinda Boyers
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
| | - Francesca Parrini
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
| | - Norman Owen-Smith
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
| | - Barend F N Erasmus
- Global Change Institute, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
| | - Robyn S Hetem
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Jan Smuts Avenue, Braamfontein 2000, Johannesburg, South Africa
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Rodríguez-Peñate AE, Escudero A, Martínez I, Madrigal-González J. Unveiling annual growth chronologies from inter-nodal branch elongations in a fruticose lichen in southern Europe. Fungal Biol 2019; 123:824-829. [PMID: 31627858 DOI: 10.1016/j.funbio.2019.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 11/19/2022]
Abstract
Techniques for retrospective analysis of size dynamics at annual resolution remain poorly developed in lichens in general, and fruticose lichens in particular. Only a few attempts in very high latitudes suggested that growth might be studied as a chronosequence of inter-nodal branch elongations. Here we evaluated, for the first time, this hypothesis in a dry Mediterranean environment using the lichen Cladonia rangiformis as a case study. Mixed models supported a strong positive relationship between humidity measured as precipitation/PET and inter-nodal branch elongations. Importantly, model selection suggested that (i) the number of intermodal elongations were a major determinant of stem elongation, and (ii) a second-order temporal autocorrelation denoted legacies of environmental influences at least over the next 2 y. The strong growth-humidity relationship, along with the potential legacies observed, support the idea that inter-nodal branch elongations could be used to reconstruct growth chronologies at annual resolution in drylands. This finding highlights the high vulnerability of these organisms to rising aridity, and opens a new venue for climate reconstruction and other potential applications in Ecology and Earth Science disciplines.
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Affiliation(s)
- Alba E Rodríguez-Peñate
- Departamento de ciencias de la vida, UD Ecología, Facultad de Ciencias, Universidad de Alcalá, ctra. Madrid-Barcelona km 34.6, 28805 Alcalá de Henares, Spain.
| | - Adrián Escudero
- Departamento de Biología y Geología, Física y Química Inorgánica, Unidad de Biodiversidad y Conservación, ESCET, Universidad Rey Juan Carlos, C/ Tulipán s/n, Móstoles, C.P. 28933 Madrid, Spain.
| | - Isabel Martínez
- Departamento de Biología y Geología, Física y Química Inorgánica, Unidad de Biodiversidad y Conservación, ESCET, Universidad Rey Juan Carlos, C/ Tulipán s/n, Móstoles, C.P. 28933 Madrid, Spain.
| | - Jaime Madrigal-González
- Departamento de ciencias de la vida, UD Ecología, Facultad de Ciencias, Universidad de Alcalá, ctra. Madrid-Barcelona km 34.6, 28805 Alcalá de Henares, Spain; Climate Change Impacts and Risks in the Anthropocene (C-CIA), Institute for Environmental Sciences (IES), University of Geneva, 66 Boulevard Carl Vogt, CH-1205 Geneva, Switzerland.
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25
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Nunes A, Köbel M, Pinho P, Matos P, Costantini EAC, Soares C, de Bello F, Correia O, Branquinho C. Local topographic and edaphic factors largely predict shrub encroachment in Mediterranean drylands. Sci Total Environ 2019; 657:310-318. [PMID: 30543980 DOI: 10.1016/j.scitotenv.2018.11.475] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 11/29/2018] [Accepted: 11/30/2018] [Indexed: 06/09/2023]
Abstract
Shrub encroachment influences several ecosystem services in drylands worldwide. Yet, commonly used strategies to reduce encroachment show a low medium-term success, calling for a better understanding of its causes. Previous works identified multiple drivers responsible for this phenomenon, including anthropogenic and environmental causes. However, the relative effect of climate, topography and edaphic factors on shrub encroachment is not fully understood nor has been properly quantified in Mediterranean Basin drylands. Also, understanding how these drivers lead to changes in plant communities' functional traits associated to shrub encroachment is crucial, considering traits influence ecosystem processes and associated ecosystem services. Here, we studied the understory of a Mediterranean dryland ecosystem composed of savanna-like Holm-oak woodlands, along a regional climatic gradient. We specifically assessed (i) how climatic, topographic and edaphic factors influence understory relative shrub cover (RSC) and (ii) their direct and indirect effects (via RSC) on plant functional traits. We studied the mean and diversity of 12 functional traits related to plant regeneration, establishment, and dispersal, at the community-level. We found that, under similar low-intensity land use, topographic and edaphic factors, namely slope variations and soil C:N ratio, were the most important predictors of shrub encroachment, determining communities' functional characteristics. Climate, namely summer precipitation, had a much lesser influence. Our model explained 52% of the variation in relative shrub cover. Climate had a stronger effect on a set of functional traits weakly involved in shrub encroachment, related to flowering and dispersal strategies. We show that shrub encroachment is largely predicted by topo-edaphic factors in Mediterranean drylands subject to conventional low-intensity land use. Hence, management strategies to reduce encroachment need to take these drivers into account for efficient forecasting and higher cost-effectiveness. Our results suggest that climate change might not greatly impact shrub encroachment in the Mediterranean Basin, but may affect functional structure and reduce functional diversity of plant communities, thus affecting ecosystem functioning.
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Affiliation(s)
- Alice Nunes
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2, Piso 5, 1749-016 Lisboa, Portugal.
| | - Melanie Köbel
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2, Piso 5, 1749-016 Lisboa, Portugal.
| | - Pedro Pinho
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2, Piso 5, 1749-016 Lisboa, Portugal; CERENA - Centro de Recursos Naturais e Ambiente, Universidade de Lisboa, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Paula Matos
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2, Piso 5, 1749-016 Lisboa, Portugal.
| | | | - Cristina Soares
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2, Piso 5, 1749-016 Lisboa, Portugal.
| | - Francesco de Bello
- Institute of Botany, Czech Academy of Sciences, CZ-37982 Trebon, Czech Republic.
| | - Otília Correia
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2, Piso 5, 1749-016 Lisboa, Portugal.
| | - Cristina Branquinho
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2, Piso 5, 1749-016 Lisboa, Portugal.
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26
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Koutroulis AG. Dryland changes under different levels of global warming. Sci Total Environ 2019; 655:482-511. [PMID: 30476829 DOI: 10.1016/j.scitotenv.2018.11.215] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/13/2018] [Accepted: 11/14/2018] [Indexed: 06/09/2023]
Abstract
Drylands are vital ecosystems which cover almost 47% of the Earth's surface, hosting 39% of the global population. Dryland areas are highly sensitive to climatic changes and substantial impacts are foreseen under a warming climate. Many studies have examined the evolution of drylands in the future highlighting the need for improved capability of climate models to simulate aridity. The present study takes advantage of new higher resolution climate projections by the HadGEM3A Atmosphere Global Climate Model using prescribed time varying SSTs and sea ice, provided by a range of CMIP5 climate models under RCP8.5. The aim of the higher resolution models is to examine the benefit of the improved representation of atmospheric processes in the dryland research and to see where these results lie in the range of results from previous studies using the original CMIP5 ensemble. The transient response of aridity from the recent past until the end of the 21st century was examined as well as the expansion of global drylands under specific levels of global warming (1.5 °C, 2 °C and 4 °C). Dryland changes were further assessed at the watershed level for a number of major global river basins to discuss implications on hydrological changes and land degradation. The areal coverage of drylands could increase by an additional 7% of the global land surface by 2100 under high end climate change. At a 4 °C warmer world above pre-industrial, 11.2% of global land area is projected to shift towards drier types and 4.24% to wetter. At the same level of warming the number of humans projected to live in drylands varies between 3.3 and 5.2 billion, depending on the socioeconomic developments. By keeping global warming levels to 1.5 °C, up to 1.9 billion people could avoid living in drylands compared to a 4 °C warmer world of low environmental concern.
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Lian C, Zuo X, Tian L. A possible role of biogenic silica in esophageal cancer in North China? Environ Sci Pollut Res Int 2019; 26:8340-8343. [PMID: 30689109 DOI: 10.1007/s11356-019-04332-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Certain areas in North China have the highest incidence of esophageal squamous cell carcinoma (ESCC) in the world, which has not seen convincing explanation by any risk factor yet. Biogenic silica in millet bran was linked to ESCC in the early 1980s but the hypothesis was largely dismissed because of the lack of geographic correlation between millet consumption and ESCC. Later epidemiological studies disclosed the linkage of wheat consumption in North China to ESCC instead. Now, we hypothesize silica phytoliths (silicified bodies that have definite shapes) from wheat chaff are a major etiologic factor of ESCC in this region. This hypothesis is supported by the potentially high abundance of silica phytoliths on the bracts of wheat (Triticum aestivum) in North China due to favorable Si-accumulation genotype, arid climate, and siallitic soil with bioavailable Si. These silica phytoliths can contaminate wheat flour and cause repeated local injuries in the esophagus and stimulate proliferation by providing anchorage.
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Affiliation(s)
- Changhong Lian
- Department of Surgical Oncology, Heping Hospital, Changzhi Medical College, Changzhi, China
| | - Xinxin Zuo
- State Key Laboratory for Subtropical Mountain Ecology, College of Geogrophical Sciences, Fujian Normal University, Fuzhou, China
| | - Linwei Tian
- School of Public Health, The University of Hong Kong, 7 Sassoon Road, Hong Kong, SAR, China.
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Šmíd J, Göçmen B, Crochet PA, Trape JF, Mazuch T, Uvizl M, Nagy ZT. Ancient diversification, biogeography, and the role of climatic niche evolution in the Old World cat snakes (Colubridae, Telescopus). Mol Phylogenet Evol 2019; 134:35-49. [PMID: 30703516 DOI: 10.1016/j.ympev.2019.01.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 01/25/2023]
Abstract
The process of species diversification is often associated with niche shifts in the newly arising lineages so that interspecific competition is minimized. However, an opposing force known as niche conservatism causes that related species tend to resemble each other in their niche requirements. Due to the inherent multidimensionality of niche space, some niche components may be subject to divergent evolution while others remain conserved in the process of speciation. One such possible component is the species' climatic niche. Here, we test the role of climatic niche evolution on the diversification of the Old World cat snakes of the genus Telescopus. These slender, nocturnal snakes are distributed in arid and semiarid areas throughout Africa, southwest Asia and adjoining parts of Europe. Because phylogenetic relationships among the Telescopus species are virtually unknown, we generated sequence data for eight genetic markers from ten of the 14 described species and reconstructed a time-calibrated phylogeny of the genus. Phylogenetic analysesindicate that the genus is of considerably old origin that dates back to the Eocene/Oligocene boundary. Biogeographical analyses place the ancestor of the genus in Africa, where it diversified into the species observed today and from where it colonized Arabia and the Levant twice independently. The colonization of Arabia occurred in the Miocene, that of the Levant either in the Late Oligocene or Early Miocene. We then identified temperature and precipitation niche space and breadth of the species included in the phylogeny and examined whether there is phylogenetic signal in these climatic niche characteristics. Despite the vast range of the genus and its complex biogeographic history, most Telescopus species have similar environmental requirements with preference for arid to semiarid conditions. One may thus expect that the genus' climatic niche will be conserved. However, our results suggest that most of the climatic niche axes examined show no phylogenetic signal, being indicative of no evolutionary constraints on the climatic niche position and niche breadth in Telescopus. The only two variables with positive phylogenetic signal (temperature niche position and precipitation niche breadth) evolved under the Brownian motion model, also indicating no directional selection on these traits. As a result, climatic niche evolution does not seem to be the major driver for the diversification in Telescopus.
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29
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Huang M, Chai L, Jiang D, Zhang M, Zhao Y, Huang Y. Increasing aridity affects soil archaeal communities by mediating soil niches in semi-arid regions. Sci Total Environ 2019; 647:699-707. [PMID: 30092526 DOI: 10.1016/j.scitotenv.2018.07.305] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 07/21/2018] [Accepted: 07/22/2018] [Indexed: 05/15/2023]
Abstract
Soil archaea plays a vital role in the functioning of dryland ecosystems, which are expected to expand and get drier in the future as a result of climate change. However, compared with bacteria and fungi, the impacts of increasing aridity on archaea in these ecosystems remain largely unknown. Here, soil samples were collected along a typical aridity gradient in semi-arid regions in Inner Mongolia, China, to investigate whether and how the increasing aridity affects archaeal communities. The results showed that archaeal richness linearly decreased with increasing aridity. After partialling out the effects of soil properties based on partial least squares regression, the significant aridity-richness relationship vanished. The composition of archaeal communities was distributed according to the aridity gradient. These variations were largely driven by the changes in the relative abundance of Thaumarchaeota, Euryarchaeota and unclassified phyla. Niche-based processes were predominant in structuring the observed archaeal aridity-related pattern. The structural equation models further showed that aridity indirectly reduced archaeal richness through improving soil electrical conductivity (EC) and structured community composition by changing soil total nitrogen (TN). These results suggested that soil salinization and N-losses might be important mechanisms underlying the increasing aridity-induced alterations in archaeal communities, and highlighted the importance of soil niches in mediating the indirect impacts of increasing aridity on archaea.
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Affiliation(s)
- Muke Huang
- College of Environmental Science and Engineering, Peking University, Beijing 100871, China
| | - Liwei Chai
- College of Environmental Science and Engineering, Peking University, Beijing 100871, China
| | - Dalin Jiang
- Graduate School of Life and Environmental Science, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Mengjun Zhang
- College of Environmental Science and Engineering, Peking University, Beijing 100871, China
| | - Yanran Zhao
- College of Environmental Science and Engineering, Peking University, Beijing 100871, China
| | - Yi Huang
- College of Environmental Science and Engineering, Peking University, Beijing 100871, China.
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Liu C, Huang W, Feng S, Chen J, Zhou A. Spatiotemporal variations of aridity in China during 1961-2015: decomposition and attribution. Sci Bull (Beijing) 2018; 63:1187-99. [PMID: 36751088 DOI: 10.1016/j.scib.2018.07.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/11/2018] [Accepted: 07/05/2018] [Indexed: 11/21/2022]
Abstract
Changes in global climate intensify the hydrological cycle, directly influence precipitation, evaporation, runoff, and cause the re-distribution of water resources in time and space. The aridity index (AI), defined as the ratio of annual precipitation to annual potential evapotranspiration, is a widely used numerical indicator to quantify the degree of dryness at a given location. This study examined the effects of climate change on AI in China during 1961-2015. The results showed that the nationally averaged AI experienced a notable interdecadal transition in 1993, characterized by increasing AI (wetter) between 1961 and 1993, and decreasing AI (drier) after 1993. Overall, the decreased solar radiation (solar dimming) was the main factor affected the nationally averaged AI during 1961-1993, while the relative humidity dominated the variations of nationally averaged AI during 1993-2015. However, the roles of individual factors on the changes in AI vary in different subregions. Precipitation is one of the important contributing factors for the changes of AI in almost all subregions, except the Mid-Lower Yangtze and Huaihe basins. Solar radiation has been significantly decreased during 1961-1993 in South China, Southwest China, Mid-Lower Yangtze and Huaihe basins, and the Tibetan Plateau. Therefore, it dominated the trends of AI in these subregions. The relative humidity mainly affected the Mid-Lower Yangtze and Huaihe basins, Southwest China, and the Tibetan Plateau during 1993-2015, hence dominated the trends of AI in these subregions. The changes of temperature and wind speed, however, played a relatively weak role in the variations of AI.
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deCastro-Arrazola I, Hortal J, Moretti M, Sánchez-Piñero F. Spatial and temporal variations of aridity shape dung beetle assemblages towards the Sahara desert. PeerJ 2018; 6:e5210. [PMID: 30258704 PMCID: PMC6151256 DOI: 10.7717/peerj.5210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 06/19/2018] [Indexed: 11/30/2022] Open
Abstract
Background Assemblage responses to environmental gradients are key to understand the general principles behind the assembly and functioning of communities. The spatially and temporally uneven distribution of water availability in drylands creates strong aridity gradients. While the effects of spatial variations of aridity are relatively well known, the influence of the highly-unpredictable seasonal and inter-annual precipitations on dryland communities has been seldom addressed. Aims Here, we study the seasonal and inter-annual responses of dung beetle (Coleoptera, Scarabaeidae) communities to the variations of water availability along a semiarid region of the Mediterranean. Methods We surveyed a 400 km linear transect along a strong aridity gradient from the Mediterranean coast to the Sahara (Eastern Morocco), during four sampling campaigns: two in the wet season and two in the dry season. We measured species richness, abundance and evenness. Variations in community composition between sites, seasons and years were assessed through beta diversity partitioning of dissimiliarity metrics based on species occurrences and abundances. The effects of climate, soil, vegetation and dung availability were evaluated using Spearman-rank correlations, general linear regressions and partial least-squares generalized linear regressions for community structure, and non-metric multi-dimensional scaling, Permutational Analysis of Variance (PERMANOVA) and distance-based RDA variation partitioning for compositional variations. Results Dung beetle abundance and species richness showed large seasonal variations, but remained relatively similar between years. Indeed, aridity and its interaction with season and year were the strongest correlates of variations in species richness and composition. Increasing aridity resulted in decreasing species richness and an ordered replacement of species, namely the substitution of the Mediterranean fauna by desert assemblages dominated by saprophagous and generalist species both in space towards the Sahara and in the dry season. Discussion Our study shows that aridity determines composition in dung beetle communities, filtering species both in space and time. Besides the expected decrease in species richness, such environmental filtering promotes a shift towards generalist and saprophagous species in arid conditions, probably related to changes in resource quality along the transect and through the year. Our results highlight the importance of considering the effects of the highly-unpredictable seasonal and inter-annual variations in precipitation when studying dryland communities.
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Affiliation(s)
- Indradatta deCastro-Arrazola
- Department of Biogeography and Global Change, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain.,Departamento de Zoología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Joaquín Hortal
- Department of Biogeography and Global Change, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain.,Department of Ecology, Instituto de Ciências Biologicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Marco Moretti
- Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
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Robertson LP, Hall CR, Forster PI, Carroll AR. Alkaloid diversity in the leaves of Australian Flindersia (Rutaceae) species driven by adaptation to aridity. Phytochemistry 2018; 152:71-81. [PMID: 29734038 DOI: 10.1016/j.phytochem.2018.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/06/2018] [Accepted: 04/22/2018] [Indexed: 06/08/2023]
Abstract
The genus Flindersia (Rutaceae) comprises 17 species of mostly Australian endemic trees. Although most species are restricted to rainforests, four have evolved to grow in semi-arid and arid environments. In this study, the leaf alkaloid diversity of rainforest and semi-arid/arid zone adapted Australian Flindersia were compared by LC/MS-MS and NMR spectroscopy. Contrary to expectations, Flindersia alkaloid diversity was strongly correlated with environmental aridity, where species predominating in drier regions produced more alkaloids than their wet rainforest congenerics. Rainforest species were also more chemically similar to each other than were the four semi-arid/arid zone species. There was a significant relationship between the presence of alkaloid structural classes and phylogenetic distance, suggesting that alkaloid profiles are influenced by both genetic and environmental factors. The results suggest that the radiation of Flindersia species out of the rainforest and into drier environments has promoted the evolution of unique alkaloid diversity. Plants growing in arid and semi-arid regions of Australia may represent an untapped source of undescribed specialised metabolites.
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Affiliation(s)
- Luke P Robertson
- Environmental Futures Research Institute, Griffith University, Southport 4222, Gold Coast, Australia; Griffith Institute for Drug Discovery, Griffith University, Nathan 4111, Brisbane, Australia
| | - Casey R Hall
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond 2753, Australia
| | - Paul I Forster
- Queensland Herbarium, Department of Science, Information Technology, Innovation and the Arts, Brisbane Botanic Gardens, Toowong 4066, Queensland, Australia
| | - Anthony R Carroll
- Environmental Futures Research Institute, Griffith University, Southport 4222, Gold Coast, Australia; Griffith Institute for Drug Discovery, Griffith University, Nathan 4111, Brisbane, Australia.
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Duncan FD, Hanrahan SA. Respiratory patterns in field collected brown locust, Locustana pardalina, in the gregarious phase. J Insect Physiol 2018; 106:209-216. [PMID: 29339231 DOI: 10.1016/j.jinsphys.2018.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 11/22/2017] [Accepted: 01/11/2018] [Indexed: 06/07/2023]
Abstract
In this paper we report on the metabolic rates and respiratory patterns measured from gregarious brown locusts, Locustana pardalina, collected from the Nama Karoo region in South Africa. All five instar hopper stages and adults were collected over a three year period when significant numbers of locust swarms were seen. Flow-through respirometry was used to measure the CO2 emission from individual locusts from all the developmental stages and adults within a week of collection. Carbon dioxide emission scaled hypometrically with mass, 0.863 ± 0.026. Except in the 1st and 5th instar stage there was no difference in the mass specific rate of CO2 emission (V̇<ce:small-caps>CO2</ce:small-caps>). These had significantly higher metabolic rates compared to the other stages which reflects their biology, with the 1st instar undergoing rapid growth and the 5th instar also undergoing rapid growth and development in preparation for becoming an adult. The 1st instars used a form of continuous gas exchange while all the other stages showed discontinuous gas exchange cycles. A clear burst phase and interburst periods could be seen. The 2nd and 3rd instars use mainly diffusion to expel CO2 and so exhibited an open form of the burst phase. There was an increase in CO2 volleys seen in the burst phase from the 4th instar stage onwards thus indicating an increased use of convection. There was no change in the duration or frequency of the discontinuous gas exchange cycles through the locust development or with body mass.
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Affiliation(s)
- Frances D Duncan
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, Private Bag 3, WITS 2050, South Africa.
| | - Shirley A Hanrahan
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, Private Bag 3, WITS 2050, South Africa
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Nolan RH, Sinclair J, Eldridge DJ, Ramp D. Biophysical risks to carbon sequestration and storage in Australian drylands. J Environ Manage 2018; 208:102-111. [PMID: 29248786 DOI: 10.1016/j.jenvman.2017.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/29/2017] [Accepted: 12/02/2017] [Indexed: 06/07/2023]
Abstract
Carbon abatement schemes that reduce land clearing and promote revegetation are now an important component of climate change policy globally. There is considerable potential for these schemes to operate in drylands which are spatially extensive. However, projects in these environments risk failure through unplanned release of stored carbon to the atmosphere. In this review, we identify factors that may adversely affect the success of vegetation-based carbon abatement projects in dryland ecosystems, evaluate their likelihood of occurrence, and estimate the potential consequences for carbon storage and sequestration. We also evaluate management strategies to reduce risks posed to these carbon abatement projects. Identified risks were primarily disturbances, including unplanned fire, drought, and grazing. Revegetation projects also risk recruitment failure, thereby failing to reach projected rates of sequestration. Many of these risks are dependent on rainfall, which is highly variable in drylands and susceptible to further variation under climate change. Resprouting vegetation is likely to be less vulnerable to disturbance and have faster recovery rates upon release from disturbance. We conclude that there is a strong impetus for identifying management strategies and risk reduction mechanisms for carbon abatement projects. Risk mitigation would be enhanced by effective co-ordination of mitigation strategies at scales larger than individual abatement project boundaries, and by implementing risk assessment throughout project planning and implementation stages. Reduction of risk is vital for maximising carbon sequestration of individual projects and for reducing barriers to the establishment of new projects entering the market.
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Affiliation(s)
- Rachael H Nolan
- Centre for Compassionate Conservation, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia.
| | - Jennifer Sinclair
- Centre for Compassionate Conservation, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia; GreenCollar, The Rocks, Sydney, NSW 2000, Australia
| | - David J Eldridge
- School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052, Australia
| | - Daniel Ramp
- Centre for Compassionate Conservation, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
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Wright BR, Fensham RJ. Fire after a mast year triggers mass recruitment of slender mulga (Acacia aptaneura), a desert shrub with heat-stimulated germination. Am J Bot 2017; 104:1474-1483. [PMID: 29885224 DOI: 10.3732/ajb.1700008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 09/19/2017] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Fire typically triggers extensive regeneration of plants with heat-stimulated germination by causing short periods of intense soil heating. If plants with heat-stimulated germination are also subject to seed predation and display mast-seeding cycles, postfire recruitment may be contingent on the seedfall density of prefire masts, and on whether granivores are satiated at the time of fire. METHODS We conducted a longitudinal seedbank study and a mensurative field experiment in central Australia to examine whether fire and the variation in seedfall density across sites in a mast year interact to influence recruitment of slender mulga (Acacia aptaneura), an iteroparous masting shrub with heat-stimulated germination. KEY RESULT The seedbank study showed seedbank pulsing after masting, with mean seed counts in the upper 4-cm soil layer being 132.8 seeds/m2 12-mo after a dense seedfall, but only 3.8 seeds/m2 following a year with no seed production. Consistent with this, recruitment increased postfire at sites where denser seedfall had occurred during the preburn mast year. Conversely, little recruitment occurred at unburnt populations, irrespective of prefire seedfall density. CONCLUSIONS We attribute our findings to: (1) elevated soil temperatures during fires stimulating germination of heat-cued seeds; and (2) granivore satiation following masting facilitating assimilation of seeds into the soil seedbank. These results highlight the importance of rare seed-input events for regeneration in fire-prone systems dominated by masting plants, and provide the first example from an arid biome of fire interacting with masting to influence recruitment.
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Affiliation(s)
- Boyd R Wright
- Botany, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2350, Australia
- School of Agriculture and Food Sciences, University of Queensland, St. Lucia, Queensland 4072, Australia
- The Northern Territory Herbarium, Department of Land Resource Management, Alice Springs, Northern Territory 0871, Australia
| | - Roderick J Fensham
- School of Biological Sciences, University of Queensland, St. Lucia, Queensland 4072, Australia
- Queensland Herbarium, Mt Coot-tha Rd, Toowong, Brisbane, Queensland 4066, Australia
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Liancourt P, Le Bagousse-Pinguet Y, Rixen C, Dolezal J. SGH: stress or strain gradient hypothesis? Insights from an elevation gradient on the roof of the world. Ann Bot 2017; 120:29-38. [PMID: 28444363 PMCID: PMC5737727 DOI: 10.1093/aob/mcx037] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/15/2017] [Indexed: 06/01/2023]
Abstract
BACKGROUND AND AIMS The stress gradient hypothesis (SGH), the view that competition prevails in undisturbed and productive environments, and shifts to facilitation in disturbed or stressful environments, has become a central paradigm in ecology. However, an alternative view proposes that the relationship between biotic interactions and environmental severity should be unimodal instead of monotonic. Possible causes of discrepancies between these two views were examined in the high elevation desert of the arid Trans-Himalayas. METHODS A putative nurse species and its associated plant community was surveyed over its entire elevation range, spanning from alpine to desert vegetation belts. The results were analysed at the community level (vegetation cover and species richness), considering the distinction between the intensity and the importance of biotic interactions. Interactions at the species level (pairwise interactions) were also considered, i.e. the variation of biotic interactions within the niche of a species, for which the abundance (species cover) and probability of occurrence (presence/absence) for the most widespread species along the gradient were distinguished. KEY RESULTS Overall, facilitation was infrequent in our study system; however, it was observed for the two most widespread species. At the community level, the intensity and importance of biotic interactions showed a unimodal pattern. The departure from the prediction of the SGH happened abruptly where the nurse species entered the desert vegetation belt at the lowest elevation. This abrupt shift was attributed to the turnover of species with contrasting tolerances. At the species level, however, facilitation increased consistently as the level of stress increases and individuals deviate from their optimum (increasing strain). CONCLUSION While the stress gradient hypothesis was not supported along our elevation gradient at the community level, the strain gradient hypothesis, considering how species perceive the ambient level of stress and deviate from their optimum, provided a parsimonious explanation for the outcome of plant-plant interactions at both scales.
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Affiliation(s)
- Pierre Liancourt
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, 379 82 Trebon, Czech Republic
| | - Yoann Le Bagousse-Pinguet
- Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/ Tulipán s/n, 28933 Móstoles, Spain
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland
| | - Jiri Dolezal
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, 379 82 Trebon, Czech Republic
- Department of Botany, Faculty of Science, University of South Bohemia, Na Zlate stoce 1, 370 05 Ceske Budejovice, Czech Republic
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Martin C, Maureille B, Amiot R, Touzeau A, Royer A, Fourel F, Panczer G, Flandrois JP, Lécuyer C. Record of Nile seasonality in Nubian neonates. Isotopes Environ Health Stud 2017; 53:223-242. [PMID: 28276733 DOI: 10.1080/10256016.2016.1229667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/30/2016] [Indexed: 06/06/2023]
Abstract
The oxygen isotope compositions of bones (n = 11) and teeth (n = 20) from 12 Sudanese individuals buried on Sai Island (Nubia) were analysed to investigate the registration of the evolution of the Nile environment from 3700 to 500 years BP and the potential effects of ontogeny on the oxygen isotope ratios. The isotopic compositions were converted into the composition of drinking water, ultimately originating from the Nile. δ18O values decrease during ontogeny; this is mainly related to breastfeeding and physiology. Those of neonates present very large variations. Neonates have a very high bone turnover and are thus able to record seasonal δ18O variations of the Nile waters. These variations followed a pattern very similar to the present one. Nile δ18O values increased from 1.4 to 4.4 ‰ (Vienna Standard Mean Ocean Water) from the Classic Kerma (∼3500 BP) through the Christian period (∼1000 BP), traducing a progressive drying of Northeast Africa.
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Affiliation(s)
- Céline Martin
- a Laboratoire de Géologie de Lyon LGL-TPE, UMR CNRS 5276, Université Claude Bernard Lyon 1 , Villeurbanne , France
- h Aix-Marseille Université, CNRS, IRD, CEREGE UM34 , Aix-en-Provence , France
| | - Bruno Maureille
- b PACEA, UMR CNRS 5199, Université de Bordeaux , Pessac , France
| | - Romain Amiot
- a Laboratoire de Géologie de Lyon LGL-TPE, UMR CNRS 5276, Université Claude Bernard Lyon 1 , Villeurbanne , France
| | | | - Aurélien Royer
- d Université de Bourgogne, Biogéosciences, UMR CNRS 6282 , Dijon , France
- e Ecole Pratique des Hautes Etudes, Laboratoire EPHE PALEVO , Dijon , France
| | - François Fourel
- a Laboratoire de Géologie de Lyon LGL-TPE, UMR CNRS 5276, Université Claude Bernard Lyon 1 , Villeurbanne , France
| | - Gérard Panczer
- f Institut Lumière Matière, UMR5306, Université Claude Bernard Lyon1-CNRS, Université de Lyon , Villeurbanne , France
| | - Jean-Pierre Flandrois
- g LBBE, UMR CNRS 5558, Université de Lyon 1 , Faculté de Médecine Lyon-Sud , Villeurbanne , France
| | - Christophe Lécuyer
- a Laboratoire de Géologie de Lyon LGL-TPE, UMR CNRS 5276, Université Claude Bernard Lyon 1 , Villeurbanne , France
- i Institut Universitaire de France , Paris , France
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Cerdán M, Sánchez-Sánchez A, Jordá JD, Amat B, Cortina J, Ruiz-Vicedo N, El-Khattabi M. Characterization of water dissolved organic matter under woody vegetation patches in semi-arid Mediterranean soils. Sci Total Environ 2016; 553:340-348. [PMID: 26930307 DOI: 10.1016/j.scitotenv.2016.02.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/03/2016] [Accepted: 02/13/2016] [Indexed: 06/05/2023]
Abstract
Woody patches in semiarid environments favor the establishment of other plants. Facilitation may be favored by an increase in soil fertility. Dissolved organic matter (DOM), is the most active fraction of soil organic matter and may contain compounds affecting plant establishment, as allelochemicals, hormone-like substances and metal carriers. However, information on DOM contents and composition in these environments is scarce. In this paper, we study the impact of woody patches on DOM in Stipa tenacissima L. steppes and discuss its implications for community dynamics. DOM under patch- and inter-patch areas, was analyzed for elemental composition, UV-Vis indices and organic acid content. Element concentration and composition in DOM, and organic acid concentration were similar in patch- and inter-patch areas. Yet, soils under patches were richer in DOC, aromatic species and organic acids (particularly fumaric acid) than soils in inter-patch areas. Dominant species affected organic matter concentration and quality in complex ways. Thus, patches dominated by Ephedra fragilis showed higher concentrations of TOC and aromatics than those dominated by other species. Rhamnus lycioides patches showed the highest accumulation of fumaric acid, which may contribute to its successful recruitment rate and expansion in the area. Our results show substantial differences in the amount and composition of DOM and specific compounds affecting soil functionality and plant dynamics. Further studies on the effects of such changes on seedling performance are needed to increase our understanding of plant-plant interactions in semiarid environments.
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Affiliation(s)
- M Cerdán
- Dep. Agrochemistry and Biochemistry, Faculty of Sciences, University of Alicante, Ap. 99, 03080 Alicante, Spain
| | - A Sánchez-Sánchez
- Dep. Agrochemistry and Biochemistry, Faculty of Sciences, University of Alicante, Ap. 99, 03080 Alicante, Spain
| | - J D Jordá
- Institute for Environmental Research, Ramon Margalef, University of Alicante, Ap. 99, 03080 Alicante, Spain.
| | - B Amat
- Department of Ecology, Faculty of Sciences, University of Alicante, Ap. 99, 03080 Alicante, Spain
| | - J Cortina
- Institute for Environmental Research, Ramon Margalef, University of Alicante, Ap. 99, 03080 Alicante, Spain; Department of Ecology, Faculty of Sciences, University of Alicante, Ap. 99, 03080 Alicante, Spain
| | - N Ruiz-Vicedo
- Dep. Agrochemistry and Biochemistry, Faculty of Sciences, University of Alicante, Ap. 99, 03080 Alicante, Spain
| | - M El-Khattabi
- Dep. Agrochemistry and Biochemistry, Faculty of Sciences, University of Alicante, Ap. 99, 03080 Alicante, Spain
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Soliveres S, Maestre FT, Ulrich W, Manning P, Boch S, Bowker MA, Prati D, Delgado-Baquerizo M, Quero JL, Schöning I, Gallardo A, Weisser W, Müller J, Socher SA, García-Gómez M, Ochoa V, Schulze ED, Fischer M, Allan E. Intransitive competition is widespread in plant communities and maintains their species richness. Ecol Lett 2015; 18:790-798. [PMID: 26032242 DOI: 10.1111/ele.12456] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/20/2015] [Accepted: 04/28/2015] [Indexed: 11/27/2022]
Abstract
Intransitive competition networks, those in which there is no single best competitor, may ensure species coexistence. However, their frequency and importance in maintaining diversity in real-world ecosystems remain unclear. We used two large data sets from drylands and agricultural grasslands to assess: (1) the generality of intransitive competition, (2) intransitivity-richness relationships and (3) effects of two major drivers of biodiversity loss (aridity and land-use intensification) on intransitivity and species richness. Intransitive competition occurred in > 65% of sites and was associated with higher species richness. Intransitivity increased with aridity, partly buffering its negative effects on diversity, but was decreased by intensive land use, enhancing its negative effects on diversity. These contrasting responses likely arise because intransitivity is promoted by temporal heterogeneity, which is enhanced by aridity but may decline with land-use intensity. We show that intransitivity is widespread in nature and increases diversity, but it can be lost with environmental homogenisation.
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Affiliation(s)
- Santiago Soliveres
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Fernando T Maestre
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Calle Tulipán S/N, 28933, Móstoles, Spain
| | - Werner Ulrich
- Chair of Ecology and Biogeography Nicolaus Copernicus University in Toruń Lwowska1, 87-100, Toruń, Poland
| | - Peter Manning
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Steffen Boch
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Matthew A Bowker
- School of Forestry, Northern Arizona University, 200 East Pine Knoll Drive, 86011, Flagstaff, AZ, USA
| | - Daniel Prati
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Manuel Delgado-Baquerizo
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, 2751, New South Wales, Australia
| | - José L Quero
- Departamento de Ingeniería Forestal, Escuela Técnica Superior de Ingeniería Agronómica y de Montes, Universidad de Córdoba, Edificio Leonardo da Vinci, 1ª planta. Campus de Rabanales, Ctra N-IV km 396. C.P, 14071, Córdoba, Spain
| | - Ingo Schöning
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Antonio Gallardo
- Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Carretera de Utrera kilómetro 1, 41013, Sevilla, Spain
| | - Wolfgang Weisser
- Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, School of Life Sciences Weihenstephan, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, Freising, Germany
| | - Jörg Müller
- Institut für Biochemie und Biologie, Universität Potsdam, Maulbeerallee 1, 14469, Potsdamm, Germany
| | - Stephanie A Socher
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Miguel García-Gómez
- Departamento de Ingeniería y Morfología del Terreno, Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Calle Profesor Aranguren S/N, 28040, Madrid, Spain
| | - Victoria Ochoa
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Calle Tulipán S/N, 28933, Móstoles, Spain
| | - Ernst-Detlef Schulze
- Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany
| | - Markus Fischer
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
| | - Eric Allan
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland
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Horrocks NP, Hine K, Hegemann A, Ndithia HK, Shobrak M, Ostrowski S, Williams JB, Matson KD, Tieleman BI. Are antimicrobial defences in bird eggs related to climatic conditions associated with risk of trans-shell microbial infection? Front Zool 2014; 11:49. [PMID: 25057281 PMCID: PMC4107615 DOI: 10.1186/1742-9994-11-49] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 06/21/2014] [Indexed: 11/23/2022] Open
Abstract
Introduction All bird eggs are exposed to microbes in the environment, which if transmitted to the developing embryo, could cause hatching failure. However, the risk of trans-shell infection varies with environmental conditions and is higher for eggs laid in wetter environments. This might relate to generally higher microbial abundances and diversity in more humid environments, including on the surface of eggshells, as well as the need for moisture to facilitate microbial penetration of the eggshell. To protect against microbial infection, the albumen of avian eggs contains antimicrobial proteins, including lysozyme and ovotransferrin. We tested whether lysozyme and ovotransferrin activities varied in eggs of larks (Alaudidae) living along an arid-mesic gradient of environmental aridity, which we used as a proxy for risk of trans-shell infection. Results Contrary to expectations, lysozyme activity was highest in eggs from hotter, more arid locations, where we predicted the risk of trans-shell infection would be lower. Ovotransferrin concentrations did not vary with climatic factors. Temperature was a much better predictor of antimicrobial protein activity than precipitation, a result inconsistent with studies stressing the importance of moisture for trans-shell infection. Conclusions Our study raises interesting questions about the links between temperature and lysozyme activity in eggs, but we find no support for the hypothesis that antimicrobial protein deposition is higher in eggs laid in wetter environments.
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Affiliation(s)
- Nicholas Pc Horrocks
- Animal Ecology Group, Centre for Ecological & Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands ; Department of Zoology, University of Cambridge, Downing Street, CB2 3EJ Cambridge, UK
| | - Kathryn Hine
- Animal Ecology Group, Centre for Ecological & Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands
| | - Arne Hegemann
- Animal Ecology Group, Centre for Ecological & Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands
| | - Henry K Ndithia
- Animal Ecology Group, Centre for Ecological & Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands ; Department of Ornithology, National Museums of Kenya, PO Box 40658, Nairobi, Kenya
| | - Mohammed Shobrak
- Biology Department, Science College, Taif University, P.O. Box 888, 21974 Taif, Saudi Arabia
| | - Stéphane Ostrowski
- Wildlife Conservation Society, 2300 Southern Boulevard, 10460 Bronx, NY, USA
| | - Joseph B Williams
- Department of Evolution, Ecology & Organismal Biology, Ohio State University, 43210 Columbus, OH, USA
| | - Kevin D Matson
- Animal Ecology Group, Centre for Ecological & Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands
| | - B Irene Tieleman
- Animal Ecology Group, Centre for Ecological & Evolutionary Studies, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands
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Abstract
We present a phylogenetic study of black fungi in lichens, primarily
focusing on saxicolous samples from seasonally arid habitats in Armenia, but
also with examples from other sites. Culturable strains of lichen-associated
black fungi were obtained by isolation from surface-washed lichen material.
Determination is based on ITS rDNA sequence data and comparison with published
sequences from other sources. The genera Capnobotryella,
Cladophialophora, Coniosporium, Mycosphaerella, and
Rhinocladiella were found in different lichen species, which showed
no pathogenic symptoms. A clade of predominantly lichen-associated strains is
present only in Rhinocladiella, whereas samples of the remaining
genera were grouped more clearly in clades with species from other sources.
The ecology of most-closely related strains indicates that
Capnobotryella and Coniosporium, and perhaps also
Rhinocladiella strains opportunistically colonise lichens. In
contrast, high sequence divergence in strains assigned to
Mycosphaerella could indicate the presence of several lichen-specific
species with unknown range of hosts or habitats, which are distantly related
to plant-inhabitants. Similar applies to Cladophialophora strains,
where the closest relatives of the strains from lichens are serious human
pathogens.
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Affiliation(s)
- S Harutyunyan
- Institut für Pflanzenwissenschaften, Karl-Franzens-Universität Graz, Holteigasse 6, A-8010 Graz, Austria
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