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Kou X, Liu H, Chen H, Xu Z, Yu X, Cao X, Liu D, Wen L, Zhuo Y, Wang L. Multifunctionality and maintenance mechanism of wetland ecosystems in the littoral zone of the northern semi-arid region lake driven by environmental factors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 870:161956. [PMID: 36737024 DOI: 10.1016/j.scitotenv.2023.161956] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/28/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
The relationship between biodiversity and ecosystem multifunctionality (BEMF) has become an ecological research hot spot in recent years. Changes in biodiversity are non-randomly distributed in space and time in natural ecosystems, and the BEMF relationship is affected by a combination of biotic and abiotic factors. These complex, uncertain relationships are affected by research scale and quantification and measurement indicators. This paper took the Daihai littoral zone wetlands in Inner Mongolia as the research object to reveal the dynamic succession of wetland vegetation and ecosystem function change characteristics and processes during the shrinkage of the lake. The main findings were as follows: the combined effect of aboveground (species and functions) and belowground (bacteria and fungi) diversity was greater than the effect of single components on ecosystem multifunctionality (EMF) (R2 = 80.00 %). Soil salinity (EC) had a direct negative effect on EMF (λ = -0.22), and soil moisture (SM) had a direct positive effect on EMF (λ = 0.19). The results of the hierarchical partitioning analysis showed that plant species richness (Margalef index) was the ideal indicator to explain the EMF and C, N, and P cycling functions in littoral zone wetlands with explanations of 12.25 %, 7.31 %, 7.83 %, and 5.33 %, respectively. The EMF and C and P cycles were mainly affected by bacterial diversity, and the N cycle was mainly affected by fungal abundance in belowground biodiversity. Margalef index and sand content affected EMF through cascading effects of multiple nutrients (FDis, CWMRV, CWMLCC, and bacterial and fungal abundance and diversity) in littoral zone wetlands. This paper provides a reference for exploring the multifunctionality maintenance mechanisms of natural littoral zone wetland ecosystems in the context of global change, and it also provides important theoretical support and basic data for the implementation of ecological restoration in Daihai lake.
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Affiliation(s)
- Xin Kou
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Huamin Liu
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Han Chen
- School of Business Administration and Humanities, Mongolian University of Science & Technology, Ulaanbaatar 46/520, Mongolia
| | - Zhichao Xu
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Xiaowen Yu
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Xiaoai Cao
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Dongwei Liu
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Lu Wen
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Yi Zhuo
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Lixin Wang
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Collaborative Innovation Center for Grassland Ecological Security (Jointly Supported by the Ministry of Education of China and Inner Mongolia Autonomous Region), Hohhot 010021, China; Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, Hohhot 010021, China.
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2
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Raath‐Krüger MJ, Schöb C, McGeoch MA, Burger DA, Strydom T, le Roux PC. Long‐term spatially‐replicated data show no physical cost to a benefactor species in a facilitative plant–plant interaction. OIKOS 2022. [DOI: 10.1111/oik.09617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Morgan J. Raath‐Krüger
- Dept of Zoology, Centre for Ecological Genomics and Wildlife Conservation, Univ. of Johannesburg Auckland Park South Africa
| | - Christian Schöb
- Inst. of Agricultural Sciences, ETH Zürich Zürich Switzerland
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Móstoles Madrid Spain
| | - Melodie A. McGeoch
- Dept of Ecology, Environment and Evolution, School of Life Sciences, La Trobe Univ. Bundoora Victoria Australia
| | - Divan A. Burger
- Dept of Statistics, Univ. of Pretoria Pretoria South Africa
- Cytel Inc. Waltham MA USA
| | - Tanya Strydom
- Dept of Plant and Soil Sciences, Univ. of Pretoria Pretoria South Africa
| | - Peter C. le Roux
- Dept of Plant and Soil Sciences, Univ. of Pretoria Pretoria South Africa
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3
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Song G, Hui R, Yang H, Wang B, Li X. Biocrusts mediate the plant community composition of dryland restoration ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 844:157135. [PMID: 35809721 DOI: 10.1016/j.scitotenv.2022.157135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
Degradation and expansion are current threats associated with drylands. During natural or artificial restoration, dryland ecosystems tend to contain a unique community, namely, biocrusts. Studies have shown that biocrusts serve multiple functions and have the potential to accelerate or inhibit degradation. However, the mechanisms by which biocrusts mediate dryland plant community structure and composition remain largely unknown. In this study, we performed a series of pot experiments under greenhouse conditions at three disturbance levels (strong, moderate and no disturbance) and at three rainfall gradients (- 50 %, normal, + 50 %) for different biocrust types. Our objective was to examine how biocrusts influence the introduction and establishment of different functional forms of plant species during the different succession stages of dryland recovery. Our results showed that biocrusts have significantly different effects on the seed germination and survival of the tested plant species. Although strong disturbances to the biocrusts and increasing rainfall alleviated the inhibitory effects of biocrusts on the perennial herb (S. glareosa) and subshrub (C. latens) species, these factors could only promote the temporary survival of these two plants in the revegetated area. These results indicate that biocrusts in revegetated systems play important sieving functions during plant species establishment. Additionally, the survival of S. viridis, a plant species with small seeds adapted to the current habitat, was promoted in the community, but two plant species that are currently unsuitable, S. glareosa and C. latens, were filtered out by the biocrusts. Our conclusions suggest that biocrusts play an ecological filtering role in plant species introduction and establishment in revegetated ecosystems and demonstrate the scientific significance of biocrusts in maintaining the health and stability of dryland ecosystems.
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Affiliation(s)
- Guang Song
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou, Gansu 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
| | - Rong Hui
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou, Gansu 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
| | - Haotian Yang
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou, Gansu 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
| | - Bingyao Wang
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou, Gansu 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
| | - Xinrong Li
- Shapotou Desert Research and Experimental Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou, Gansu 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China.
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4
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Wei Y, Jing X, Su F, Li Z, Wang F, Guo H. Does
pH
matter for ecosystem multifunctionality? An empirical test in a semi‐arid grassland on the Loess Plateau. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Yanan Wei
- College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing, Jiangsu 210095 China
- Chinese Research Academy of Environmental Sciences Beijing, 100012 China
| | - Xin Jing
- State Key Laboratory of Grassland Agro‐Ecosystems, and College of Pastoral Agriculture Science and Technology Lanzhou University Lanzhou, Gansu, 730020 China
| | - Fanglong Su
- College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing, Jiangsu 210095 China
| | - Zhen Li
- College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing, Jiangsu 210095 China
| | - Fuwei Wang
- College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing, Jiangsu 210095 China
| | - Hui Guo
- College of Resources and Environmental Sciences Nanjing Agricultural University Nanjing, Jiangsu 210095 China
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5
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Morillas L, Roales J, Cruz C, Munzi S. Non-Toxic Increases in Nitrogen Availability Can Improve the Ability of the Soil Lichen Cladonia rangiferina to Cope with Environmental Changes. J Fungi (Basel) 2022; 8:jof8040333. [PMID: 35448564 PMCID: PMC9025437 DOI: 10.3390/jof8040333] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/11/2022] [Accepted: 03/16/2022] [Indexed: 11/30/2022] Open
Abstract
Climate change and atmospheric nitrogen (N) deposition on drylands are greatly threatening these especially vulnerable areas. Soil biocrust-forming lichens in drylands can provide early indicators of these disturbances and play a pivotal role, as they contribute to key ecosystem services. In this study, we explored the effects of different long-term water availability regimes simulating climate changes and their interaction with N addition on the physiological response of the soil lichen Cladonia rangiferina. Three sets of this lichen were subjected to control, reduced watering, and reduced watering and N addition (40 kg NH4NO3 ha−1 year−1) treatments for 16 months. Finally, all samples were subjected to daily hydration cycles with N-enriched water at two levels (40 and 80 kg NH4NO3 ha−1 year−1) for 23 days. We found that reduced watering significantly decreased the vitality of this lichen, whereas N addition unexpectedly helped lichens subjected to reduced watering to cope with stress produced by high temperatures. We also found that long-term exposure to N addition contributed to the acclimation to higher N availability. Overall, our data suggest that the interactions between reduced watering and increased N supply and temperature have an important potential to reduce the physiological performance of this soil lichen.
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Affiliation(s)
- Lourdes Morillas
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016 Lisbon, Portugal; (J.R.); (C.C.); (S.M.)
- Correspondence:
| | - Javier Roales
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016 Lisbon, Portugal; (J.R.); (C.C.); (S.M.)
- Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Ctra. Utrera Km 1, 41013 Seville, Spain
| | - Cristina Cruz
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016 Lisbon, Portugal; (J.R.); (C.C.); (S.M.)
| | - Silvana Munzi
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 1749-016 Lisbon, Portugal; (J.R.); (C.C.); (S.M.)
- Centro Interuniversitário de História das Ciências e da Tecnologia Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
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6
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Souza JMT, Vázquez DP, Varassin IG. Abundance and phenology drive plant–pollinator network responses to restoration in the Southern Atlantic rainforest in Brazil. Restor Ecol 2021. [DOI: 10.1111/rec.13588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Jana M. T. Souza
- Departamento Acadêmico de Química e Biologia Universidade Tecnológica Federal do Paraná Rua Deputado Heitor de Alencar Furtado, 5000, CEP 81280‐340, Curitiba, Paraná Brazil
| | - Diego P. Vázquez
- Instituto Argentino de Investigaciones de las Zonas Áridas CONICET and Universidad Nacional de Cuyo CC 507, 5500 Mendoza Argentina
- Facultad de Ciencias Exactas y Naturales Universidad Nacional de Cuyo Mendoza Argentina
| | - Isabela G. Varassin
- Laboratório de Interações e Biologia Reprodutiva Universidade Federal do Paraná CEP 81531‐980, Curitiba, Paraná Brazil
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7
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Kang L, Chen L, Zhang D, Peng Y, Song Y, Kou D, Deng Y, Yang Y. Stochastic processes regulate belowground community assembly in alpine grasslands on the Tibetan Plateau. Environ Microbiol 2021; 24:179-194. [PMID: 34750948 DOI: 10.1111/1462-2920.15827] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/13/2021] [Accepted: 10/19/2021] [Indexed: 01/10/2023]
Abstract
Understanding biogeographical patterns and underlying processes of belowground community assembly is crucial for predicting soil functions and their responses to global environmental change. However, little is known about potential differences of belowground community assembly among bacteria, fungi, protists and soil animals, particularly for alpine ecosystems. Based on the combination of large-scale field sampling, high-throughput marker-gene sequencing and multiple statistical analyses, we explored patterns and drivers of belowground community assembly in alpine grasslands on the Tibetan Plateau. Our results revealed that the distance-decay rates varied among trophic levels, with organisms of higher trophic level having weaker distance-decay pattern. The spatial and environmental variables explained limited variations of belowground communities. By contrast, the stochastic processes, mainly consisting of dispersal limitation and drift, played a primary role in regulating belowground community assembly. Moreover, the relative importance of stochastic processes varied among trophic levels, with the role of dispersal limitation weakening whereas that of drift enhancing in the order of bacteria, fungi, protists and soil animals. These findings advance our understanding of patterns and mechanisms driving belowground community assembly in alpine ecosystems and provide a reference basis for predicting the dynamics of ecosystem functions under changing environment.
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Affiliation(s)
- Luyao Kang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Leiyi Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Dianye Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yunfeng Peng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yutong Song
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dan Kou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Ye Deng
- University of Chinese Academy of Sciences, Beijing 100049, China.,CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuanhe Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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8
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Snail Mucus Increases the CO2 Efflux of Biological Soil Crusts. Ecosystems 2021. [DOI: 10.1007/s10021-021-00670-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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9
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Biogeographical patterns and mechanisms of microbial community assembly that underlie successional biocrusts across northern China. NPJ Biofilms Microbiomes 2021; 7:15. [PMID: 33547284 PMCID: PMC7864921 DOI: 10.1038/s41522-021-00188-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/14/2021] [Indexed: 01/30/2023] Open
Abstract
Biocrusts play critical eco-functions in many drylands, however it is challenging to explore their community assembly, particularly within patched successional types and across climate zones. Here, different successional biocrusts (alga, lichen, and moss-dominated biocrusts) were collected across the northern China, and assembly of biocrust microbial communities was investigated by high-throughput sequencing combined with measurements of soil properties and microclimate environments. Bacterial and eukaryotic communities showed that the maximum and minimum community variation occurred across longitude and latitude, respectively. In the regions where all three stages of biocrusts were involved, the highest community difference existed between successional stages, and decreased with distance. The community assembly was generally driven by dispersal limitation, although neutral processes have controlled the eukaryotic community assembly in hyperarid areas. Along the succession, bacterial community had no obvious patterns, but eukaryotic community showed increasing homogeneity, with increased species sorting and decreased dispersal limitation for community assembly. Compared to early successional biocrusts, there were higher microbial mutual exclusions and more complex networks at later stages, with distinct topological features. Correlation analysis further indicated that the balance between deterministic and stochastic processes might be mediated by aridity, salinity, and total phosphorus, although the mediations were opposite for bacteria and eukaryotes.
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10
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Wetland hydroperiod predicts community structure, but not the magnitude of cross-community congruence. Sci Rep 2021; 11:429. [PMID: 33432086 PMCID: PMC7801406 DOI: 10.1038/s41598-020-80027-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 12/11/2020] [Indexed: 01/29/2023] Open
Abstract
A major focus in community ecology is understanding how biological interactions and environmental conditions shape horizontal communities. However, few studies have explored whether cross-community interactions are consistent or non-stationary across environmental gradients. Using the relative abundance of birds, aquatic macroinvertebrates and plants, we examined how cross-community congruence varied between short and long-hydroperiod prairie pothole wetlands in southern Alberta. These wetlands are structured by their hydroperiod: the length of time that ponded water is present in the wetland. We compared the strength of cross-community congruence and the strength of congruence between each horizontal community and wetland hydroperiod in wetlands that typically contain ponded water throughout the year to wetlands that dry up every summer. The strength of cross-community relationships was similar between more permanent and more ephemeral wetland classes, suggesting that biological interactions have a near equivalent role in shaping community composition, regardless of hydroperiod. However, because cross-community congruence, measured as the Procrustes pseudo-R value, was, on average, 77% ± SE 12% greater than that between each horizontal community and measures of wetland hydroperiod, we concluded that community structure is not shaped by hydroperiod alone. We attribute the observed cross-community congruence to (1) plants and aquatic macroinvertebrates influence birds through habitat and food provisioning, and (2) birds influence plants and aquatic macroinvertebrates by dispersing their propagules.
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11
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Guo T. Grazing Exclusion Effects on the Relationship between Species Richness and Vegetation Cover in Mongolian Grasslands. POLISH JOURNAL OF ECOLOGY 2020. [DOI: 10.3161/15052249pje2020.68.3.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Tong Guo
- Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China e-mail:
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12
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Duncan C, Good MK, Sluiter I, Cook S, Schultz NL. Soil reconstruction after mining fails to restore soil function in an Australian arid woodland. Restor Ecol 2020. [DOI: 10.1111/rec.13166] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Corrine Duncan
- School of Health and Life Sciences Federation University Mount Helen Victoria 3350 Australia
| | - Megan K. Good
- BioSciences University of Melbourne Parkville Victoria 3052 Australia
| | - Ian Sluiter
- School of Health and Life Sciences Federation University Mount Helen Victoria 3350 Australia
| | - Simon Cook
- School of Health and Life Sciences Federation University Mount Helen Victoria 3350 Australia
| | - Nick L. Schultz
- School of Health and Life Sciences Federation University Mount Helen Victoria 3350 Australia
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13
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Habitat-dependent composition of bacterial and fungal communities in biological soil crusts from Oman. Sci Rep 2019; 9:6468. [PMID: 31015576 PMCID: PMC6478931 DOI: 10.1038/s41598-019-42911-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 04/09/2019] [Indexed: 11/08/2022] Open
Abstract
Biological soil crusts (biocrusts) occur within drylands throughout the world, covering ~12% of the global terrestrial soil surface. Their occurrence in the deserts of the Arabian Peninsula has rarely been reported and their spatial distribution, diversity, and microbial composition remained largely unexplored. We investigated biocrusts at six different locations in the coastal and central deserts of Oman. The biocrust types were characterized, and the bacterial and fungal community compositions of biocrusts and uncrusted soils were analysed by amplicon sequencing. The results were interpreted based on the environmental parameters of the different sites. Whereas at lowland sites, mainly cyanobacteria-dominated biocrusts were observed, both cyanobacteria- and lichen-dominated biocrusts occurred at mountain sites. The majority of bacterial sequences (32–83% of total sequences) belonged to Actinobacteria, Cyanobacteria, Alphaproteobacteria, and Bacteroidetes, whereas fungal sequences belonged to Ascomycota, Basidiomycota, and Chytridiomycota (>95%). With biocrust development, a notable increase in cyanobacterial and decrease in actinobacterial proportions was observed for cyanobacteria-dominated crusts. In coastal areas, where salinity is high, biocrusts were replaced by a unique marine mat-like microbial community, dominated by halotolerant taxa. Redundancy analysis revealed a significant contribution of soil texture, cover type, carbon content, and elevation to the variations in bacterial and fungal communities. Multivariate analysis placed microbial communities in significantly separated clusters based on their carbon content, elevation and electrical conductivity. We conclude that Oman hosts a variety of cyanobacteria- and lichen-dominated crusts with their bacterial and fungal communities being largely dictated by soil properties and environmental parameters.
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14
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van der Plas F. Biodiversity and ecosystem functioning in naturally assembled communities. Biol Rev Camb Philos Soc 2019; 94:1220-1245. [PMID: 30724447 DOI: 10.1111/brv.12499] [Citation(s) in RCA: 117] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 01/08/2019] [Accepted: 01/11/2019] [Indexed: 01/10/2023]
Abstract
Approximately 25 years ago, ecologists became increasingly interested in the question of whether ongoing biodiversity loss matters for the functioning of ecosystems. As such, a new ecological subfield on Biodiversity and Ecosystem Functioning (BEF) was born. This subfield was initially dominated by theoretical studies and by experiments in which biodiversity was manipulated, and responses of ecosystem functions such as biomass production, decomposition rates, carbon sequestration, trophic interactions and pollination were assessed. More recently, an increasing number of studies have investigated BEF relationships in non-manipulated ecosystems, but reviews synthesizing our knowledge on the importance of real-world biodiversity are still largely missing. I performed a systematic review in order to assess how biodiversity drives ecosystem functioning in both terrestrial and aquatic, naturally assembled communities, and on how important biodiversity is compared to other factors, including other aspects of community composition and abiotic conditions. The outcomes of 258 published studies, which reported 726 BEF relationships, revealed that in many cases, biodiversity promotes average biomass production and its temporal stability, and pollination success. For decomposition rates and ecosystem multifunctionality, positive effects of biodiversity outnumbered negative effects, but neutral relationships were even more common. Similarly, negative effects of prey biodiversity on pathogen and herbivore damage outnumbered positive effects, but were less common than neutral relationships. Finally, there was no evidence that biodiversity is related to soil carbon storage. Most BEF studies focused on the effects of taxonomic diversity, however, metrics of functional diversity were generally stronger predictors of ecosystem functioning. Furthermore, in most studies, abiotic factors and functional composition (e.g. the presence of a certain functional group) were stronger drivers of ecosystem functioning than biodiversity per se. While experiments suggest that positive biodiversity effects become stronger at larger spatial scales, in naturally assembled communities this idea is too poorly studied to draw general conclusions. In summary, a high biodiversity in naturally assembled communities positively drives various ecosystem functions. At the same time, the strength and direction of these effects vary highly among studies, and factors other than biodiversity can be even more important in driving ecosystem functioning. Thus, to promote those ecosystem functions that underpin human well-being, conservation should not only promote biodiversity per se, but also the abiotic conditions favouring species with suitable trait combinations.
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Affiliation(s)
- Fons van der Plas
- Systematic Botany and Functional Biodiversity, Institute of Biology, Leipzig University, Johannisallee 21-23, 04103 Leipzig, Germany
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15
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Baecher JA, Richter SC. Environmental gradients in old-growth Appalachian forest predict fine-scale distribution, co-occurrence, and density of woodland salamanders. Ecol Evol 2018; 8:12940-12952. [PMID: 30619595 PMCID: PMC6308888 DOI: 10.1002/ece3.4736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 07/18/2018] [Accepted: 09/14/2018] [Indexed: 11/09/2022] Open
Abstract
Woodland salamanders are among the most abundant vertebrate animals in temperate deciduous forests of eastern North America. Because of their abundance, woodland salamanders are responsible for the transformation of nutrients and translocation of energy between highly disparate levels of trophic organization: detrital food webs and high-order predators. However, the spatial extent of woodland salamanders' role in the ecosystem is likely contingent upon the distribution of their biomass throughout the forest. We sought to determine if natural environmental gradients influence the fine-scale distribution and density of Southern Ravine Salamanders (Plethodon richmondi) and Cumberland Plateau Salamanders (P. kentucki). We addressed this objective by constructing occupancy, co-occurrence, and abundance models from temporally replicated surveys within an old-growth forest in the Cumberland Plateau region of Kentucky. We found that Plethodon richmondi had a more restricted fine-scale distribution than P. kentucki (mean occupancy probability [ψ ¯ ^ ] = 0.737) and exhibited variable density, from <250 to >1000 individuals per hectare, associated with increased soil moisture and reduced solar exposure due to slope face. While more ubiquitously distributed (ψ ¯ ^ = 0.95), P. kentucki density varied from <400 to >1,000 individuals per hectare and was inversely related to increased solar exposure from canopy disturbance and landscape convexity. Our data suggest co-occurrence patterns of P. richmondi and P. kentucki are influenced primarily by abiotic conditions within the forest, and that populations likely occur independently and without evidence of biotic interaction. Given the critical role that woodland salamanders play in the maintenance of forest health, regions that support large populations of woodland salamanders, such as those highlighted in this study-mesic forest stands on north-to-east facing slopes with dense canopy and abundant natural cover, may provide enhanced ecosystem services and support the stability of the total forest.
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Affiliation(s)
- J. Alex Baecher
- Department of Biological Sciences and Division of Natural AreasEastern Kentucky UniversityRichmondKentucky
| | - Stephen C. Richter
- Department of Biological Sciences and Division of Natural AreasEastern Kentucky UniversityRichmondKentucky
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16
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Mensens C, De Laender F, Janssen CR, Rivera FC, Sabbe K, De Troch M. Selective and context-dependent effects of chemical stress across trophic levels at the basis of marine food webs. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:1342-1353. [PMID: 29698586 DOI: 10.1002/eap.1737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 11/01/2017] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Human activities increasingly impact the functioning of marine food webs, but anthropogenic stressors are seldom included in ecological study designs. Diet quality, as distinct from just diet quantity, has moreover rarely been highlighted in food web studies in a stress context. We measured the effects of metal and pesticide stress (copper and atrazine) on the contribution of a benthic intertidal diatom community to two processes that are key to the functioning of intertidal systems: biomass (diet quantity) and lipid (diet quality) production. We then examined if stressors affected diatom functioning by selectively targeting the species contributing most to functioning (selective stress effects) or by changing the species' functional contribution (context-dependent effects). Finally, we tested if stress-induced changes in diet quality altered the energy flow to the diatoms' main grazers (harpacticoid copepods). Diatom diet quantity was reduced by metal stress but not by low pesticide levels due to the presence of an atrazine-tolerant, mixotrophic species. Selective effects of the pesticide reduced diatom diet quality by 60% and 75% at low and high pesticide levels respectively, by shifting diatom community structure from dominance by lipid-rich species toward dominance by an atrazine-tolerant, but lipid-poor, species. Context-dependent effects did not affect individual diatom lipid content at low levels of both stressors, but caused diatoms to lose 40% of their lipids at high copper stress. Stress-induced changes in diet quality predicted the energy flow from the diatoms to their copepod consumers, which lost half of their lipids when feeding on diatoms grown under low and high pesticide and high metal stress. Selective pesticide effects were a more important threat for trophic energy transfer than context-dependent effects of both stressors, with shifts in diatom community structure affecting the energy flow to their copepod grazers at stress levels where no changes in diatom lipid content were detected.
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Affiliation(s)
- Christoph Mensens
- Biology Department, Marine Biology, Ghent University, Krijgslaan 281 - S8, 9000, Ghent, Belgium
- Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Coupure Links 653, Building F, 9000, Ghent, Belgium
| | - Frederik De Laender
- Research Unit in Environmental and Evolutionary Biology, Biology Department, Université de Namur, Rue de Bruxelles 61, 5000, Namur, Belgium
| | - Colin R Janssen
- Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Coupure Links 653, Building F, 9000, Ghent, Belgium
| | - Frances Camille Rivera
- Biology Department, Marine Biology, Ghent University, Krijgslaan 281 - S8, 9000, Ghent, Belgium
| | - Koen Sabbe
- Biology Department, Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281 - S8, 9000, Ghent, Belgium
| | - Marleen De Troch
- Biology Department, Marine Biology, Ghent University, Krijgslaan 281 - S8, 9000, Ghent, Belgium
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17
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Baert JM, Eisenhauer N, Janssen CR, De Laender F. Biodiversity effects on ecosystem functioning respond unimodally to environmental stress. Ecol Lett 2018; 21:1191-1199. [PMID: 29869373 DOI: 10.1111/ele.13088] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 03/18/2018] [Accepted: 04/17/2018] [Indexed: 01/03/2023]
Abstract
Understanding how biodiversity (B) affects ecosystem functioning (EF) is essential for assessing the consequences of ongoing biodiversity changes. An increasing number of studies, however, show that environmental conditions affect the shape of BEF relationships. Here, we first use a game-theoretic community model to reveal that a unimodal response of the BEF slope can be expected along environmental stress gradients, but also how the ecological mechanisms underlying this response may vary depending on how stress affects species interactions. Next, we analysed a global dataset of 44 experiments that crossed biodiversity with environmental conditions. Confirming our main model prediction, the effect of biodiversity on ecosystem functioning tends to be greater at intermediate levels of environmental stress, but varies among studies corresponding to differences in stress-effects on species interactions. Together, these results suggest that increases in stress from ongoing global environmental changes may amplify the consequences of biodiversity changes.
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Affiliation(s)
- Jan M Baert
- Laboratory of Environmental Toxicology and Applied Ecology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.,Behavioural Ecology and Ecophysiology Research Group, University of Antwerp, Universiteitsplein 1, 2610, Antwerp, Belgium.,Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany.,Institute of Biology, Leipzig University, Deutscher Platz 5e, 04103, Leipzig, Germany
| | - Colin R Janssen
- Laboratory of Environmental Toxicology and Applied Ecology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Frederik De Laender
- Institute of Life-Earth-Environment, Namur Institute of Complex Systems, Research Unit of Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, 5000, Namur, Belgium
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18
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Yue K, García‐Palacios P, Parsons SA, Yang W, Peng Y, Tan B, Huang C, Wu F. Assessing the temporal dynamics of aquatic and terrestrial litter decomposition in an alpine forest. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13143] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Kai Yue
- Long‐term Research Station of Alpine Forest EcosystemsProvincial Key Laboratory of Ecological Forestry EngineeringInstitute of Ecology and ForestrySichuan Agricultural University Chengdu China
- Center for Biodiversity Dynamics in a Changing Word (BIOCHANGE)Aarhus University Aarhus C Denmark
| | - Pablo García‐Palacios
- Departamento de Biología y Geología, Física y Química Inorgánica y Analítica, Área de Biodiversidad y ConservaciónUniversidad Rey Juan Carlos Móstoles Spain
| | - Scott A. Parsons
- Collage of Science and EngineeringJames Cook University Douglas Qld Australia
| | - Wanqin Yang
- Long‐term Research Station of Alpine Forest EcosystemsProvincial Key Laboratory of Ecological Forestry EngineeringInstitute of Ecology and ForestrySichuan Agricultural University Chengdu China
| | - Yan Peng
- Department of Geosciences and Natural Resource ManagementUniversity of Copenhagen Frederiksberg C Denmark
| | - Bo Tan
- Long‐term Research Station of Alpine Forest EcosystemsProvincial Key Laboratory of Ecological Forestry EngineeringInstitute of Ecology and ForestrySichuan Agricultural University Chengdu China
| | - Chunping Huang
- College of Life ScienceSichuan Normal University Chengdu China
| | - Fuzhong Wu
- Long‐term Research Station of Alpine Forest EcosystemsProvincial Key Laboratory of Ecological Forestry EngineeringInstitute of Ecology and ForestrySichuan Agricultural University Chengdu China
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19
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Maier S, Tamm A, Wu D, Caesar J, Grube M, Weber B. Photoautotrophic organisms control microbial abundance, diversity, and physiology in different types of biological soil crusts. ISME JOURNAL 2018; 12:1032-1046. [PMID: 29445133 PMCID: PMC5864206 DOI: 10.1038/s41396-018-0062-8] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/21/2017] [Accepted: 01/10/2018] [Indexed: 01/10/2023]
Abstract
Biological soil crusts (biocrusts) cover about 12% of the Earth’s land masses, thereby providing ecosystem services and affecting biogeochemical fluxes on a global scale. They comprise photoautotrophic cyanobacteria, algae, lichens and mosses, which grow together with heterotrophic microorganisms, forming a model system to study facilitative interactions and assembly principles in natural communities. Biocrusts can be classified into cyanobacteria-, lichen-, and bryophyte-dominated types, which reflect stages of ecological succession. In this study, we examined whether these categories include a shift in heterotrophic communities and whether this may be linked to altered physiological properties. We analyzed the microbial community composition by means of qPCR and high-throughput amplicon sequencing and utilized flux measurements to investigate their physiological properties. Our results revealed that once 16S and 18S rRNA gene copy numbers increase, fungi become more predominant and alpha diversity increases with progressing succession. Bacterial communities differed significantly between biocrust types with a shift from more generalized to specialized organisms along succession. CO2 gas exchange measurements revealed large respiration rates of late successional crusts being significantly higher than those of initial biocrusts, and different successional stages showed distinct NO and HONO emission patterns. Thus, our study suggests that the photoautotrophic organisms facilitate specific microbial communities, which themselves strongly influence the overall physiological properties of biocrusts and hence local to global nutrient cycles.
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Affiliation(s)
- Stefanie Maier
- Max Planck Institute for Chemistry, Multiphase Chemistry, Mainz, Germany.
| | - Alexandra Tamm
- Max Planck Institute for Chemistry, Multiphase Chemistry, Mainz, Germany
| | - Dianming Wu
- Max Planck Institute for Chemistry, Multiphase Chemistry, Mainz, Germany.,Key Laboratory of Geographic Information Sciences, Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, China
| | - Jennifer Caesar
- Department of Agriculture & Food Sciences, University of Applied Sciences, Neubrandenburg, Germany
| | - Martin Grube
- Institute of Plant Sciences, University of Graz, Graz, Austria
| | - Bettina Weber
- Max Planck Institute for Chemistry, Multiphase Chemistry, Mainz, Germany.
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20
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Sauze J, Ogée J, Maron PA, Crouzet O, Nowak V, Wohl S, Kaisermann A, Jones SP, Wingate L. The interaction of soil phototrophs and fungi with pH and their impact on soil CO 2, CO 18O and OCS exchange. SOIL BIOLOGY & BIOCHEMISTRY 2017; 115:371-382. [PMID: 29200510 PMCID: PMC5666291 DOI: 10.1016/j.soilbio.2017.09.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 09/06/2017] [Accepted: 09/10/2017] [Indexed: 06/07/2023]
Abstract
The stable oxygen isotope composition of atmospheric CO2 and the mixing ratio of carbonyl sulphide (OCS) are potential tracers of biospheric CO2 fluxes at large scales. However, the use of these tracers hinges on our ability to understand and better predict the activity of the enzyme carbonic anhydrase (CA) in different soil microbial groups, including phototrophs. Because different classes of the CA family (α, β and γ) may have different affinities to CO2 and OCS and their expression should also vary between different microbial groups, differences in the community structure could impact the 'community-integrated' CA activity differently for CO2 and OCS. Four soils of different pH were incubated in the dark or with a diurnal cycle for forty days to vary the abundance of native phototrophs. Fluxes of CO2, CO18O and OCS were measured to estimate CA activity alongside the abundance of bacteria, fungi and phototrophs. The abundance of soil phototrophs increased most at higher soil pH. In the light, the strength of the soil CO2 sink and the CA-driven CO2-H2O isotopic exchange rates correlated with phototrophs abundance. OCS uptake rates were attributed to fungi whose abundance was positively enhanced in alkaline soils but only in the presence of increased phototrophs. Our findings demonstrate that soil-atmosphere CO2, OCS and CO18O fluxes are strongly regulated by the microbial community structure in response to changes in soil pH and light availability and supports the idea that different members of the microbial community express different classes of CA, with different affinities to CO2 and OCS.
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Affiliation(s)
- Joana Sauze
- ISPA, Bordeaux Science Agro, INRA, 33140 Villenave d’Ornon, France
| | - Jérôme Ogée
- ISPA, Bordeaux Science Agro, INRA, 33140 Villenave d’Ornon, France
| | - Pierre-Alain Maron
- Agroécologie, AgroSup Dijon, INRA, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Olivier Crouzet
- INRA, UR 251 PESSAC, Centre Versailles-Grignon, RD 10, 78026 Versailles Cedex, France
| | - Virginie Nowak
- Agroécologie, AgroSup Dijon, INRA, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Steven Wohl
- ISPA, Bordeaux Science Agro, INRA, 33140 Villenave d’Ornon, France
| | | | - Sam P. Jones
- ISPA, Bordeaux Science Agro, INRA, 33140 Villenave d’Ornon, France
| | - Lisa Wingate
- ISPA, Bordeaux Science Agro, INRA, 33140 Villenave d’Ornon, France
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21
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Alados CL, Saiz H, Gartzia M, Nuche P, Escós J, Navarro T, Pueyo Y. Plant-plant interactions scale up to produce vegetation spatial patterns: the influence of long- and short-term process. Ecosphere 2017. [DOI: 10.1002/ecs2.1915] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Concepción L. Alados
- Instituto Pirenaico de Ecología (CSIC); Avda Montañana 1005 P. O. Box 13034 E- 50080 Zaragoza Spain
| | - Hugo Saiz
- Instituto Pirenaico de Ecología (CSIC); Avda Montañana 1005 P. O. Box 13034 E- 50080 Zaragoza Spain
- Departamento de Biología y Geología; Física y Química Inorgánica; Universidad Rey Juan. Carlos; C/Tulipán s/n 28933 Móstoles Spain
| | - Maite Gartzia
- Instituto Pirenaico de Ecología (CSIC); Avda Montañana 1005 P. O. Box 13034 E- 50080 Zaragoza Spain
| | - Paloma Nuche
- Instituto Pirenaico de Ecología (CSIC); Avda Montañana 1005 P. O. Box 13034 E- 50080 Zaragoza Spain
| | - Juan Escós
- Departamento de Producción Animal y Tecnología de los Alimentos; Escuela Politécnica Superior de Huesca; Universidad de Zaragoza; E-22071 Zaragoza Spain
| | - Teresa Navarro
- Departmento de Biología Vegetal; Universidad de Málaga; PO Box 59 29080 Málaga Spain
| | - Yolanda Pueyo
- Instituto Pirenaico de Ecología (CSIC); Avda Montañana 1005 P. O. Box 13034 E- 50080 Zaragoza Spain
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22
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Al-Namazi AA, El-Bana MI, Bonser SP. Competition and facilitation structure plant communities under nurse tree canopies in extremely stressful environments. Ecol Evol 2017; 7:2747-2755. [PMID: 28428865 PMCID: PMC5395439 DOI: 10.1002/ece3.2690] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/10/2016] [Accepted: 11/20/2016] [Indexed: 11/24/2022] Open
Abstract
Nurse plant facilitation in stressful environments can produce an environment with relatively low stress under its canopy. These nurse plants may produce the conditions promoting intense competition between coexisting species under the canopy, and canopies may establish stress gradients, where stress increases toward the edge of the canopy. Competition and facilitation on these stress gradients may control species distributions in the communities under canopies. We tested the following predictions: (1) interactions between understory species shift from competition to facilitation in habitats experiencing increasing stress from the center to the edge of canopy of a nurse plant, and (2) species distributions in understory communities are controlled by competitive interactions at the center of canopy, and facilitation at the edge of the canopy. We tested these predictions using a neighbor removal experiment under nurse trees growing in arid environments. Established individuals of each of four of the most common herbaceous species in the understory were used in the experiment. Two species were more frequent in the center of the canopy, and two species were more frequent at the edge of the canopy. Established individuals of each species were subjected to neighbor removal or control treatments in both canopy center and edge habitats. We found a shift from competitive to facilitative interactions from the center to the edge of the canopy. The shift in the effect of neighbors on the target species can help to explain species distributions in these canopies. Canopy‐dominant species only perform well in the presence of neighbors in the edge microhabitat. Competition from canopy‐dominant species can also limit the performance of edge‐dominant species in the canopy microhabitat. The shift from competition to facilitation under nurse plant canopies can structure the understory communities in extremely stressful environments.
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Affiliation(s)
- Ali A Al-Namazi
- Evolution and Ecology Research Centre School of Biological, Earth and Environmental Sciences UNSW Australia Sydney NSW Australia.,King Abdulaziz City for Science and Technology (KACST) Riyadh Saudi Arabia
| | - Magdy I El-Bana
- Department of Botany Faculty of Science Port Said University Port Said Egypt
| | - Stephen P Bonser
- Evolution and Ecology Research Centre School of Biological, Earth and Environmental Sciences UNSW Australia Sydney NSW Australia
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23
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Schile LM, Callaway JC, Suding KN, Kelly NM. Can community structure track sea-level rise? Stress and competitive controls in tidal wetlands. Ecol Evol 2017; 7:1276-1285. [PMID: 28303196 PMCID: PMC5305999 DOI: 10.1002/ece3.2758] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/21/2016] [Accepted: 12/29/2016] [Indexed: 12/02/2022] Open
Abstract
Climate change impacts, such as accelerated sea-level rise, will affect stress gradients, yet impacts on competition/stress tolerance trade-offs and shifts in distributions are unclear. Ecosystems with strong stress gradients, such as estuaries, allow for space-for-time substitutions of stress factors and can give insight into future climate-related shifts in both resource and nonresource stresses. We tested the stress gradient hypothesis and examined the effect of increased inundation stress and biotic interactions on growth and survival of two congeneric wetland sedges, Schoenoplectus acutus and Schoenoplectus americanus. We simulated sea-level rise across existing marsh elevations and those not currently found to reflect potential future sea-level rise conditions in two tidal wetlands differing in salinity. Plants were grown individually and together at five tidal elevations, the lowest simulating an 80-cm increase in sea level, and harvested to assess differences in biomass after one growing season. Inundation time, salinity, sulfides, and redox potential were measured concurrently. As predicted, increasing inundation reduced biomass of the species commonly found at higher marsh elevations, with little effect on the species found along channel margins. The presence of neighbors reduced total biomass of both species, particularly at the highest elevation; facilitation did not occur at any elevation. Contrary to predictions, we documented the competitive superiority of the stress tolerator under increased inundation, which was not predicted by the stress gradient hypothesis. Multifactor manipulation experiments addressing plant response to accelerated climate change are integral to creating a more realistic, valuable, and needed assessment of potential ecosystem response. Our results point to the important and unpredicted synergies between physical stressors, which are predicted to increase in intensity with climate change, and competitive forces on biomass as stresses increase.
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Affiliation(s)
- Lisa M. Schile
- Department of Environmental Science, Policy, and ManagementUniversity of CaliforniaBerkeleyCAUSA
- Present address: Smithsonian Environmental Research Center647 Contees Wharf Rd.EdgewaterMD21037USA
| | - John C. Callaway
- Department of Environmental ScienceUniversity of San FranciscoSan FranciscoCAUSA
| | - Katharine N. Suding
- Department of Environmental Science, Policy, and ManagementUniversity of CaliforniaBerkeleyCAUSA
- Present address: Department of Ecology and Evolutionary BiologyUniversity of ColoradoRamaley N122Campus Box 334BoulderCO80309USA
| | - N. Maggi Kelly
- Department of Environmental Science, Policy, and ManagementUniversity of CaliforniaBerkeleyCAUSA
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24
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Plant spatial patterns identify alternative ecosystem multifunctionality states in global drylands. Nat Ecol Evol 2017; 1:3. [PMID: 28812618 DOI: 10.1038/s41559-016-0003] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 10/11/2016] [Indexed: 11/09/2022]
Abstract
The response of drylands to environmental gradients can be abrupt rather than gradual. These shifts largely occur unannounced and are difficult to reverse once they happen; their prompt detection is of crucial importance. The distribution of vegetation patch sizes may indicate the proximity to these shifts, but the use of this metric is hampered by a lack of large-scale studies relating these distributions to the provision of multiple ecosystem functions (multifunctionality) and comparing them to other ecosystem attributes, such as total plant cover. Here we sampled 115 dryland ecosystems across the globe and related their vegetation attributes (cover and patch size distributions) to multifunctionality. Multifunctionality followed a bimodal distribution across our sites, suggesting alternative states in the functioning of drylands. Although plant cover was the strongest predictor of multifunctionality when linear analyses were used, only patch size distributions reflected the bimodal distribution of multifunctionality observed. Differences in the coupling between nutrient cycles and in the importance of self-organizing biotic processes characterized the two multifunctionality states observed. Our findings support the use of vegetation patterns as indicators of ecosystem functioning in drylands and pave the way for developing effective strategies to monitor desertification processes.
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25
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Clare DS, Spencer M, Robinson LA, Frid CLJ. Species-Specific Effects on Ecosystem Functioning Can Be Altered by Interspecific Interactions. PLoS One 2016; 11:e0165739. [PMID: 27812164 PMCID: PMC5094745 DOI: 10.1371/journal.pone.0165739] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 10/17/2016] [Indexed: 11/18/2022] Open
Abstract
Biological assemblages are constantly undergoing change, with species being introduced, extirpated and experiencing shifts in their densities. Theory and experimentation suggest that the impacts of such change on ecosystem functioning should be predictable based on the biological traits of the species involved. However, interspecific interactions could alter how species affect functioning, with the strength and sign of interactions potentially depending on environmental context (e.g. homogenous vs. heterogeneous conditions) and the function considered. Here, we assessed how concurrent changes to the densities of two common marine benthic invertebrates, Corophium volutator and Hediste diversicolor, affected the ecological functions of organic matter consumption and benthic-pelagic nutrient flux. Complementary experiments were conducted within homogenous laboratory microcosms and naturally heterogeneous field plots. When the densities of the species were increased within microcosms, interspecific interactions enhanced effects on organic matter consumption and reduced effects on nutrient flux. Trait-based predictions of how each species would affect functioning were only consistently supported when the density of the other species was low. In field plots, increasing the density of either species had a positive effect on organic matter consumption (with no significant interspecific interactions) but no effect on nutrient flux. Our results indicate that species-specific effects on ecosystem functioning can be altered by interspecific interactions, which can be either facilitative (positive) or antagonistic (negative) depending on the function considered. The impacts of biodiversity change may therefore not be predictable based solely on the biological traits of the species involved. Possible explanations for why interactions were detected in microcosms but not in the field are discussed.
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Affiliation(s)
- David S. Clare
- School of Environmental Sciences, University of Liverpool, Brownlow Street, Liverpool, L69 3GP, United Kingdom
- * E-mail:
| | - Matthew Spencer
- School of Environmental Sciences, University of Liverpool, Brownlow Street, Liverpool, L69 3GP, United Kingdom
| | - Leonie A. Robinson
- School of Environmental Sciences, University of Liverpool, Brownlow Street, Liverpool, L69 3GP, United Kingdom
| | - Christopher L. J. Frid
- School of Environmental Sciences, University of Liverpool, Brownlow Street, Liverpool, L69 3GP, United Kingdom
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26
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Maestre FT, Eldridge DJ, Soliveres S, Kéfi S, Delgado-Baquerizo M, Bowker MA, García-Palacios P, Gaitán J, Gallardo A, Lázaro R, Berdugo M. Structure and functioning of dryland ecosystems in a changing world. ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2016; 47:215-237. [PMID: 28239303 PMCID: PMC5321561 DOI: 10.1146/annurev-ecolsys-121415-032311] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Understanding how drylands respond to ongoing environmental change is extremely important for global sustainability. Here we review how biotic attributes, climate, grazing pressure, land cover change and nitrogen deposition affect the functioning of drylands at multiple spatial scales. Our synthesis highlights the importance of biotic attributes (e.g. species richness) in maintaining fundamental ecosystem processes such as primary productivity, illustrate how N deposition and grazing pressure are impacting ecosystem functioning in drylands worldwide, and highlight the importance of the traits of woody species as drivers of their expansion in former grasslands. We also emphasize the role of attributes such as species richness and abundance in controlling the responses of ecosystem functioning to climate change. This knowledge is essential to guide conservation and restoration efforts in drylands, as biotic attributes can be actively managed at the local scale to increase ecosystem resilience to global change.
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Affiliation(s)
- Fernando T Maestre
- 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
| | - David J Eldridge
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Santiago Soliveres
- Institute of Plant Sciences, University of Bern, Alternbengrain 21, 3013 Bern, Switzerland
| | - Sonia Kéfi
- Institut des Sciences de l'Evolution, Université de Montpellier, CNRS, IRD, EPHE, CC 065, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Manuel Delgado-Baquerizo
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, 2751, New South Wales, Australia
| | - Matthew A Bowker
- School of Forestry, Northern Arizona University, 200 East Pine Knoll Drive, AZ 86011, Flagstaff, USA
| | - Pablo García-Palacios
- 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
| | - Juan Gaitán
- Instituto de Suelos, CIRN, INTA, Nicolas Repetto y de los Reseros Sin Número, 1686 Hurlingham, Buenos Aires, Argentina
| | - Antonio Gallardo
- Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Carretera de Utrera kilómetro 1, 41013 Sevilla, Spain
| | - Roberto Lázaro
- Departamento de Desertificación y Geoecología. Estación Experimental de Zonas Áridas, CSIC, Almería, Spain
| | - Miguel Berdugo
- 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
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Leach K, Montgomery WI, Reid N. Modelling the influence of biotic factors on species distribution patterns. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2016.06.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Dorado J, Vázquez DP. Flower diversity and bee reproduction in an arid ecosystem. PeerJ 2016; 4:e2250. [PMID: 27547556 PMCID: PMC4974926 DOI: 10.7717/peerj.2250] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/22/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Diverse flower communities are more stable in floral resource production along the flowering season, but the question about how the diversity and stability of resources affect pollinator reproduction remains open. High plant diversity could favor short foraging trips, which in turn would enhance bee fitness. In addition to plant diversity, greater temporal stability of floral resources in diverse communities could favor pollinator fitness because such communities are likely to occupy the phenological space more broadly, increasing floral availability for pollinators throughout the season. In addition, this potential effect of flower diversity on bee reproduction could be stronger for generalist pollinators because they can use a broader floral spectrum. Based on above arguments we predicted that pollinator reproduction would be positively correlated to flower diversity, and to temporal stability in flower production, and that this relationship would be stronger for the most generalized pollinator species. MATERIALS AND METHODS Using structural equation models, we evaluated the effect of these variables and other ecological factors on three estimates of bee reproduction (average number of brood cells per nest per site, total number of brood cells per site, and total number of nests per site), and whether such effects were modulated by bee generalization on floral resources. RESULTS Contrary to our expectations, flower diversity had no effect on bee reproduction, stability in flower production had a weakly negative effect on one of the bee reproductive variables, and the strength of the fitness-diversity relationship was unrelated to bee generalization. In contrast, elevation had a negative effect on bee reproduction, despite the narrow elevation range encompassed by our sites. DISCUSSION Flower diversity did not affect the reproduction of the solitary bees studied here. This result could stem from the context dependence of the diversity-stability relationship, given that elevation had a positive effect on flower diversity but a negative effect on bee reproduction. Although high temporal stability in flower production is expected to enhance pollinator reproduction, in our study it had a weakly negative-instead of positive-effect on the average number of brood cells per nest. Other environmental factors that vary with elevation could influence bee reproduction. Our study focused on a small group of closely-related bee species, which cautions against generalization of our findings to other groups of pollinators. More studies are clearly needed to assess the extent to which pollinator demography is influenced by the diversity of floral resources.
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Affiliation(s)
- Jimena Dorado
- Instituto Argentino de Investigaciones de Zonas Áridas, Consejo Nacional de Investigaciones Científicas y Técnicas , Mendoza , Argentina
| | - Diego P Vázquez
- Instituto Argentino de Investigaciones de Zonas Áridas, Consejo Nacional de Investigaciones Científicas y Técnicas, Mendoza, Argentina; Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
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Delgado-Baquerizo M, Maestre FT, Eldridge DJ, Singh BK. Microsite Differentiation Drives the Abundance of Soil Ammonia Oxidizing Bacteria along Aridity Gradients. Front Microbiol 2016; 7:505. [PMID: 27148194 PMCID: PMC4834304 DOI: 10.3389/fmicb.2016.00505] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 03/29/2016] [Indexed: 11/24/2022] Open
Abstract
Soil ammonia oxidizing bacteria (AOB) and archaea (AOA) are responsible for nitrification in terrestrial ecosystems, and play important roles in ecosystem functioning by modulating the rates of N losses to ground water and the atmosphere. Vascular plants have been shown to modulate the abundance of AOA and AOB in drylands, the largest biome on Earth. Like plants, biotic and abiotic features such as insect nests and biological soil crusts (biocrusts) have unique biogeochemical attributes (e.g., nutrient availability) that may modify the local abundance of AOA and AOB. However, little is known about how these biotic and abiotic features and their interactions modulate the abundance of AOA and AOB in drylands. Here, we evaluate the abundance of amoA genes from AOB and AOA within six microsites commonly found in drylands (open areas, biocrusts, ant nests, grasses, nitrogen-fixing shrubs, and trees) at 21 sites from eastern Australia, including arid and mesic ecosystems that are threatened by predicted increases in aridity. Our results from structural equation modeling suggest that soil microsite differentiation alters the abundance of AOB (but not AOA) in both arid and mesic ecosystems. While the abundance of AOA sharply increased with increasing aridity in all microsites, the response of AOB abundance was microsite-dependent, with increases (nitrogen-fixing shrubs, ant nests), decreases (open areas) or no changes (grasses, biocrusts, trees) in abundance with increasing aridity. Microsites supporting the highest abundance of AOB were trees, nitrogen-fixing shrubs, and ant nests. These results are linked to particular soil characteristics (e.g., total carbon and ammonium) under these microsites. Our findings advance our understanding of key drivers of functionally important microbial communities and N availability in highly heterogeneous ecosystems such as drylands, which may be obscured when different soil microsites are not explicitly considered.
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Affiliation(s)
| | - 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 Móstoles, Spain
| | - David J Eldridge
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney NSW, Australia
| | - Brajesh K Singh
- Hawkesbury Institute for the Environment, Western Sydney University, PenrithNSW, Australia; Global Centre for Land-Based Innovation, Western Sydney University, PenrithNSW, Australia
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Tietjen B. Same rainfall amount different vegetation—How environmental conditions and their interactions influence savanna dynamics. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2015.06.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lavender TM, Schamp BS, Lamb EG. The Influence of Matrix Size on Statistical Properties of Co-Occurrence and Limiting Similarity Null Models. PLoS One 2016; 11:e0151146. [PMID: 26942941 PMCID: PMC4778770 DOI: 10.1371/journal.pone.0151146] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 02/23/2016] [Indexed: 11/24/2022] Open
Abstract
Null models exploring species co-occurrence and trait-based limiting similarity are increasingly used to explore the influence of competition on community assembly; however, assessments of common models have not thoroughly explored the influence of variation in matrix size on error rates, in spite of the fact that studies have explored community matrices that vary considerably in size. To determine how smaller matrices, which are of greatest concern, perform statistically, we generated biologically realistic presence-absence matrices ranging in size from 3–50 species and sites, as well as associated trait matrices. We examined co-occurrence tests using the C-Score statistic and independent swap algorithm. For trait-based limiting similarity null models, we used the mean nearest neighbour trait distance (NN) and the standard deviation of nearest neighbour distances (SDNN) as test statistics, and considered two common randomization algorithms: abundance independent trait shuffling (AITS), and abundance weighted trait shuffling (AWTS). Matrices as small as three × three resulted in acceptable type I error rates (p < 0.05) for both the co-occurrence and trait-based limiting similarity null models when exclusive p-values were used. The commonly used inclusive p-value (≤ or ≥, as opposed to exclusive p-values; < or >) was associated with increased type I error rates, particularly for matrices with fewer than eight species. Type I error rates increased for limiting similarity tests using the AWTS randomization scheme when community matrices contained more than 35 sites; a similar randomization used in null models of phylogenetic dispersion has previously been viewed as robust. Notwithstanding other potential deficiencies related to the use of small matrices to represent communities, the application of both classes of null model should be restricted to matrices with 10 or more species to avoid the possibility of type II errors. Additionally, researchers should restrict the use of the AWTS randomization to matrices with fewer than 35 sites to avoid type I errors when testing for trait-based limiting similarity. The AITS randomization scheme performed better in terms of type I error rates, and therefore may be more appropriate when considering systems for which traits are not clustered by abundance.
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Affiliation(s)
- Thomas Michael Lavender
- Dept. of Plant Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail:
| | - Brandon S. Schamp
- Dept. of Biology, Algoma University, Sault Ste. Marie, Ontario, Canada
| | - Eric G. Lamb
- Dept. of Plant Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Annual grass invasion in sagebrush steppe: the relative importance of climate, soil properties and biotic interactions. Oecologia 2016; 181:543-57. [DOI: 10.1007/s00442-016-3583-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 02/06/2016] [Indexed: 01/06/2023]
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Zhang Y, Aradottir AL, Serpe M, Boeken B. Interactions of Biological Soil Crusts with Vascular Plants. BIOLOGICAL SOIL CRUSTS: AN ORGANIZING PRINCIPLE IN DRYLANDS 2016. [DOI: 10.1007/978-3-319-30214-0_19] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Structure, Composition, and Function of Biocrust Lichen Communities. BIOLOGICAL SOIL CRUSTS: AN ORGANIZING PRINCIPLE IN DRYLANDS 2016. [DOI: 10.1007/978-3-319-30214-0_7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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35
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Sancho LG, Belnap J, Colesie C, Raggio J, Weber B. Carbon Budgets of Biological Soil Crusts at Micro-, Meso-, and Global Scales. BIOLOGICAL SOIL CRUSTS: AN ORGANIZING PRINCIPLE IN DRYLANDS 2016. [DOI: 10.1007/978-3-319-30214-0_15] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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36
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Biocrusts in the Context of Global Change. BIOLOGICAL SOIL CRUSTS: AN ORGANIZING PRINCIPLE IN DRYLANDS 2016. [DOI: 10.1007/978-3-319-30214-0_22] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Climate change and physical disturbance cause similar community shifts in biological soil crusts. Proc Natl Acad Sci U S A 2015; 112:12116-21. [PMID: 26371310 DOI: 10.1073/pnas.1509150112] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biological soil crusts (biocrusts)—communities of mosses, lichens, cyanobacteria, and heterotrophs living at the soil surface—are fundamental components of drylands worldwide, and destruction of biocrusts dramatically alters biogeochemical processes, hydrology, surface energy balance, and vegetation cover. Although there has been long-standing concern over impacts of physical disturbances on biocrusts (e.g., trampling by livestock, damage from vehicles), there is increasing concern over the potential for climate change to alter biocrust community structure. Using long-term data from the Colorado Plateau, we examined the effects of 10 y of experimental warming and altered precipitation (in full-factorial design) on biocrust communities and compared the effects of altered climate with those of long-term physical disturbance (>10 y of replicated human trampling). Surprisingly, altered climate and physical disturbance treatments had similar effects on biocrust community structure. Warming, altered precipitation frequency [an increase of small (1.2 mm) summer rainfall events], and physical disturbance from trampling all promoted early successional community states marked by dramatic declines in moss cover and increases in cyanobacteria cover, with more variable effects on lichens. Although the pace of community change varied significantly among treatments, our results suggest that multiple aspects of climate change will affect biocrusts to the same degree as physical disturbance. This is particularly disconcerting in the context of warming, as temperatures for drylands are projected to increase beyond those imposed as treatments in our study.
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Sulmon C, van Baaren J, Cabello-Hurtado F, Gouesbet G, Hennion F, Mony C, Renault D, Bormans M, El Amrani A, Wiegand C, Gérard C. Abiotic stressors and stress responses: What commonalities appear between species across biological organization levels? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 202:66-77. [PMID: 25813422 DOI: 10.1016/j.envpol.2015.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 03/12/2015] [Accepted: 03/13/2015] [Indexed: 05/07/2023]
Abstract
Organisms are regularly subjected to abiotic stressors related to increasing anthropogenic activities, including chemicals and climatic changes that induce major stresses. Based on various key taxa involved in ecosystem functioning (photosynthetic microorganisms, plants, invertebrates), we review how organisms respond and adapt to chemical- and temperature-induced stresses from molecular to population level. Using field-realistic studies, our integrative analysis aims to compare i) how molecular and physiological mechanisms related to protection, repair and energy allocation can impact life history traits of stressed organisms, and ii) to what extent trait responses influence individual and population responses. Common response mechanisms are evident at molecular and cellular scales but become rather difficult to define at higher levels due to evolutionary distance and environmental complexity. We provide new insights into the understanding of the impact of molecular and cellular responses on individual and population dynamics and assess the potential related effects on communities and ecosystem functioning.
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Affiliation(s)
- Cécile Sulmon
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France.
| | - Joan van Baaren
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - Francisco Cabello-Hurtado
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - Gwenola Gouesbet
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - Françoise Hennion
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - Cendrine Mony
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - David Renault
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - Myriam Bormans
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - Abdelhak El Amrani
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France
| | - Claudia Wiegand
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France; Biologisk Institut, Syddansk Universitet, Campusvej 55, 5230 Odense M, Denmark
| | - Claudia Gérard
- UMR CNRS 6553 ECOBIO, Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France.
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Soliveres S, Smit C, Maestre FT. Moving forward on facilitation research: response to changing environments and effects on the diversity, functioning and evolution of plant communities. Biol Rev Camb Philos Soc 2015; 90:297-313. [PMID: 24774563 PMCID: PMC4407973 DOI: 10.1111/brv.12110] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 04/02/2014] [Accepted: 04/04/2014] [Indexed: 12/22/2022]
Abstract
Once seen as anomalous, facilitative interactions among plants and their importance for community structure and functioning are now widely recognized. The growing body of modelling, descriptive and experimental studies on facilitation covers a wide variety of terrestrial and aquatic systems throughout the globe. However, the lack of a general body of theory linking facilitation among different types of organisms and biomes and their responses to environmental changes prevents further advances in our knowledge regarding the evolutionary and ecological implications of facilitation in plant communities. Moreover, insights gathered from alternative lines of inquiry may substantially improve our understanding of facilitation, but these have been largely neglected thus far. Despite over 15 years of research and debate on this topic, there is no consensus on the degree to which plant-plant interactions change predictably along environmental gradients (i.e. the stress-gradient hypothesis), and this hinders our ability to predict how plant-plant interactions may affect the response of plant communities to ongoing global environmental change. The existing controversies regarding the response of plant-plant interactions across environmental gradients can be reconciled when clearly considering and determining the species-specificity of the response, the functional or individual stress type, and the scale of interest (pairwise interactions or community-level response). Here, we introduce a theoretical framework to do this, supported by multiple lines of empirical evidence. We also discuss current gaps in our knowledge regarding how plant-plant interactions change along environmental gradients. These include the existence of thresholds in the amount of species-specific stress that a benefactor can alleviate, the linearity or non-linearity of the response of pairwise interactions across distance from the ecological optimum of the beneficiary, and the need to explore further how frequent interactions among multiple species are and how they change across different environments. We review the latest advances in these topics and provide new approaches to fill current gaps in our knowledge. We also apply our theoretical framework to advance our knowledge on the evolutionary aspects of plant facilitation, and the relative importance of facilitation, in comparison with other ecological processes, for maintaining ecosystem structure, functioning and dynamics. We build links between these topics and related fields, such as ecological restoration, woody encroachment, invasion ecology, ecological modelling and biodiversity-ecosystem-functioning relationships. By identifying commonalities and insights from alternative lines of research, we further advance our understanding of facilitation and provide testable hypotheses regarding the role of (positive) biotic interactions in the maintenance of biodiversity and the response of ecological communities to ongoing environmental changes.
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Affiliation(s)
- Santiago Soliveres
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Calle Tulipán s/n, 28933 Móstoles, Spain
| | - Christian Smit
- Community and Conservation Ecology group, Centre for Evolutionary and Ecological Studies, University of Groningen, P.O. Box 11103, Nijenborg 7, 9700 CC Groningen, the Netherland
| | - Fernando T. Maestre
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Calle Tulipán s/n, 28933 Móstoles, Spain
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Escolar C, Maestre FT, Rey A. Biocrusts modulate warming and rainfall exclusion effects on soil respiration in a semi-arid grassland. SOIL BIOLOGY & BIOCHEMISTRY 2015; 80:9-17. [PMID: 25914428 PMCID: PMC4405768 DOI: 10.1016/j.soilbio.2014.09.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Soil surface communities composed of cyanobacteria, algae, mosses, liverworts, fungi, bacteria and lichens (biocrusts) largely affect soil respiration in dryland ecosystems. Climate change is expected to have large effects on biocrusts and associated ecosystem processes. However, few studies so far have experimentally assessed how expected changes in temperature and rainfall will affect soil respiration in biocrust-dominated ecosystems. We evaluated the impacts of biocrust development, increased air temperature and decreased precipitation on soil respiration dynamics during dry (2009) and wet (2010) years, and investigated the relative importance of soil temperature and moisture as environmental drivers of soil respiration, in a semiarid grassland from central Spain. Soil respiration rates were significantly lower in the dry than during the wet year, regardless of biocrust cover. Warming increased soil respiration rates, but this response was only significant in biocrust-dominated areas (> 50% biocrust cover). Warming also increased the temperature sensitivity (Q10 values) of soil respiration in biocrust-dominated areas, particularly during the wet year. The combination of warming and rainfall exclusion had similar effects in low biocrust cover areas. Our results highlight the importance of biocrusts as a modulator of soil respiration responses to both warming and rainfall exclusion, and indicate that they must be explicitly considered when evaluating soil respiration responses to climate change in drylands.
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Affiliation(s)
- Cristina Escolar
- 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, E-28933 Móstoles, Spain
| | - 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, E-28933 Móstoles, Spain
| | - Ana Rey
- Department of Biogeography and Global Change, Museo de Ciencias Naturales, C.S.I.C., Serrano 115, 28006 Madrid, Spain
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Kaiser-Bunbury CN, Vázquez DP, Stang M, Ghazoul J. Determinants of the microstructure of plant–pollinator networks. Ecology 2014. [DOI: 10.1890/14-0024.1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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42
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Soliveres S, Maestre FT. Plant-plant interactions, environmental gradients and plant diversity: a global synthesis of community-level studies. PERSPECTIVES IN PLANT ECOLOGY, EVOLUTION AND SYSTEMATICS 2014; 16:154-163. [PMID: 25914603 PMCID: PMC4407974 DOI: 10.1016/j.ppees.2014.04.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Previous syntheses on the effects of environmental conditions on the outcome of plant-plant interactions summarize results from pairwise studies. However, the upscaling to the community-level of such studies is problematic because of the existence of multiple species assemblages and species-specific responses to both the environmental conditions and the presence of neighbors. We conducted the first global synthesis of community-level studies from harsh environments, which included data from 71 alpine and 137 dryland communities. Here we: i) test how important are facilitative interactions as a driver of community structure, ii) evaluate whether the frequency of positive plant-plant interactions across differing environmental conditions and habitats is predictable, and iii) assess whether thresholds in the response of plant-plant interactions to environmental gradients exists between "moderate" and "extreme" stress levels. We also used those community-level studies performed across gradients of at least three points to evaluate how the average environmental conditions, the length of the gradient studied, and the number of points sampled across such gradient affect the form and strength of the facilitation-environment relationship. Over 25% of the species present were more spatially associated to nurse plants than expected by chance in both alpine and dryland areas, illustrating the high importance of positive plant-plant interactions for the maintenance of plant diversity. Facilitative interactions were more frequent, and more related to environmental conditions, in alpine than in dryland areas, perhaps because drylands are generally characterized by a larger variety of environmental stress factors and plant functional traits. The frequency of facilitative interactions in alpine communities peaked at 1000 mm of annual rainfall, and globally decreased with elevation. The frequency of positive interactions in dryland communities decreased globally with water scarcity or temperature annual range. Positive facilitation-drought stress relationships are more likely in shorter regional gradients, but these relationships are obscured in regions with a greater species turnover or with complex environmental gradients. By showing the different climatic drivers and behaviors of plant-plant interactions in dryland and alpine areas, our results will improve predictions regarding the effect of facilitation on the assembly of plant communities and their response to changes in environmental conditions.
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Affiliation(s)
- Santiago Soliveres
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Calle Tulipán S/N, 28933 Móstoles, Spain
- Corresponding author. . Phone: 34-914888517, Fax: 34-916647490. FTM:
| | - Fernando T. Maestre
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Calle Tulipán S/N, 28933 Móstoles, Spain
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43
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Affiliation(s)
- Jimena Dorado
- Inst. Argentino de Investigaciones de las Zonas Áridas, CONICET; CC 507, AR-5500 Mendoza Argentina
| | - Diego P. Vázquez
- Inst. Argentino de Investigaciones de las Zonas Áridas, CONICET; CC 507, AR-5500 Mendoza Argentina
- Inst. de Ciencias Básicas, Univ. Nacional de Cuyo, Centro Universitario; M5502JMA Mendoza Argentina
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Wang J, Ge Y, Chen T, Bai Y, Qian BY, Zhang CB. Facilitation drives the positive effects of plant richness on trace metal removal in a biodiversity experiment. PLoS One 2014; 9:e93733. [PMID: 24695538 PMCID: PMC3973567 DOI: 10.1371/journal.pone.0093733] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 03/08/2014] [Indexed: 11/22/2022] Open
Abstract
Background Phytoextraction is an environmentally acceptable and inexpensive technique for mine tailing rehabilitation that uses metallophyte plants. These plants reduce the soil trace metal contents to environmentally acceptable levels by accumulating trace metals. Recently, whether more trace metals can be removed by species-rich communities of these plants received great attention, as species richness has been reported having positive effects on ecosystem functions. However, how the species richness affects trace metals removal of plant communities of mine tailing is rarely known. Methodology/Principal Findings We examined the effects of species richness on soil trace metal removal in both natural and experimental plant communities. The root lengths and stem heights of each plant species were measured in order to calculate the functional diversity indices. Our results showed that trace metal (Cu, Cd, Pb and Zn) concentrations in mine tailing soil declined as species richness increased in both the natural and experimental plant communities. Species richness, rather than functional diversity, positively affected the mineralomass of the experimental plant communities. The intensity of plant-plant facilitation increased with the species richness of experimental communities. Due to the incremental role of plant-plant facilitation, most of the species had higher biomasses, higher trace metal concentrations in their plant tissues and lower malondialdehyde concentrations in their leaves. Consequently, the positive effects of species richness on mineralomass were mostly attributable to facilitation among plants. Conclusions/Significance Our results provide clear evidence that, due to plant-plant facilitation, species richness positively affects the removal of trace metals from mine tailing soil through phytoextraction and provides further information on diversity conservation and environmental remediation in a mine tailing environment.
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Affiliation(s)
- Jiang Wang
- School of Life Science, Taizhou University, Linhai, China
| | - Yuan Ge
- Bren School of Environmental Science and Management/Earth Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Tong Chen
- School of Life Science, Taizhou University, Linhai, China
| | - Yi Bai
- School of Life Science, Taizhou University, Linhai, China
| | - Bao Ying Qian
- School of Life Science, Taizhou University, Linhai, China
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Le Bagousse-Pinguet Y, Maalouf JP, Touzard B, Michalet R. Importance, but not intensity of plant interactions relates to species diversity under the interplay of stress and disturbance. OIKOS 2014. [DOI: 10.1111/oik.00961] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Escudero A, Palacio S, Maestre FT, Luzuriaga AL. Plant life on gypsum: a review of its multiple facets. Biol Rev Camb Philos Soc 2014; 90:1-18. [DOI: 10.1111/brv.12092] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Adrián Escudero
- Biodiversity and Conservation Unit, Department of Biology and Geology; Universidad Rey Juan Carlos; Móstoles Madrid E-28933 Spain
| | - Sara Palacio
- Conservation of Biodiversity and Ecosystem Restoration, Pyrenean Institute of Ecology (IPE-CSIC); Jaca Huesca E-22700 Spain
| | - Fernando T. Maestre
- Biodiversity and Conservation Unit, Department of Biology and Geology; Universidad Rey Juan Carlos; Móstoles Madrid E-28933 Spain
| | - Arantzazu L. Luzuriaga
- Biodiversity and Conservation Unit, Department of Biology and Geology; Universidad Rey Juan Carlos; Móstoles Madrid E-28933 Spain
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Maestre FT, Escolar C, de Guevara ML, Quero JL, Lázaro R, Delgado-Baquerizo M, Ochoa V, Berdugo M, Gozalo B, Gallardo A. Changes in biocrust cover drive carbon cycle responses to climate change in drylands. GLOBAL CHANGE BIOLOGY 2013; 19:3835-47. [PMID: 23818331 PMCID: PMC3942145 DOI: 10.1111/gcb.12306] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 06/06/2013] [Indexed: 05/24/2023]
Abstract
Dryland ecosystems account for ca. 27% of global soil organic carbon (C) reserves, yet it is largely unknown how climate change will impact C cycling and storage in these areas. In drylands, soil C concentrates at the surface, making it particularly sensitive to the activity of organisms inhabiting the soil uppermost levels, such as communities dominated by lichens, mosses, bacteria and fungi (biocrusts). We conducted a full factorial warming and rainfall exclusion experiment at two semiarid sites in Spain to show how an average increase of air temperature of 2-3 °C promoted a drastic reduction in biocrust cover (ca. 44% in 4 years). Warming significantly increased soil CO2 efflux, and reduced soil net CO2 uptake, in biocrust-dominated microsites. Losses of biocrust cover with warming through time were paralleled by increases in recalcitrant C sources, such as aromatic compounds, and in the abundance of fungi relative to bacteria. The dramatic reduction in biocrust cover with warming will lessen the capacity of drylands to sequester atmospheric CO2 . This decrease may act synergistically with other warming-induced effects, such as the increase in soil CO2 efflux and the changes in microbial communities to alter C cycling in drylands, and to reduce soil C stocks in the mid to long term.
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Affiliation(s)
- Fernando T. Maestre
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Spain
| | - Cristina Escolar
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Spain
| | - Mónica Ladrón de Guevara
- Estación Experimental de Zonas Áridas (CSIC), Carretera de Sacramento, s/n, 04120 La Cañada de San Urbano-Almería, Spain
| | - José L. Quero
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Spain
- Departamento de Ingeniería Forestal, Escuela Técnica Superior de Ingeniería Agronómica y de Montes, Universidad de Córdoba, Campus de Rabanales, Crta. N-IV km. 396, 14071 Córdoba, Spain
| | - Roberto Lázaro
- Estación Experimental de Zonas Áridas (CSIC), Carretera de Sacramento, s/n, 04120 La Cañada de San Urbano-Almería, Spain
| | - Manuel Delgado-Baquerizo
- Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Carretera de Utrera km. 1, 41013 Sevilla, Spain
| | - Victoria Ochoa
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Spain
| | - Miguel Berdugo
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Spain
| | - Beatriz Gozalo
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Spain
| | - Antonio Gallardo
- Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Carretera de Utrera km. 1, 41013 Sevilla, Spain
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Bakker ES, Dobrescu I, Straile D, Holmgren M. Testing the stress gradient hypothesis in herbivore communities facilitation peaks at intermediate nutrient levels. Ecology 2013; 94:1776-84. [PMID: 24015521 DOI: 10.1890/12-1175.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The role of positive interactions in structuring plant and animal communities is increasingly recognized, but the generality of current theoretical models has remained practically unexplored in animal communities. The stress gradient hypothesis predicts a linear increase in the intensity of facilitation as environmental conditions become increasingly stressful, whereas other theoretical models predict a maximum at intermediate environmental stress. We tested how competition and facilitation between herbivores change over a manipulated gradient of nutrient availability. We studied the effect of grazing by pond snails (Lymnaea stagnalis L.) as bulk grazers on aquatic caterpillars (Acentria ephemerella Denis and Schiffermüller) as small specialist grazers along an experimental gradient of environmental nutrient concentration. Higher nutrient levels increased overall total plant biomass but induced a shift toward dominance of filamentous algae at the expense of macrophytes. Facilitation of caterpillars by snail presence peaked at intermediate nutrient levels. Both caterpillar biomass and caterpillar grazing on macrophytes were highest at intermediate nutrient levels. Snails facilitated caterpillars possibly by removing filamentous algae and increasing access to the macrophyte resource, whereas they did not affect macrophyte biomass or C: nutrient ratios, a measure of food quality. We conclude that competition and facilitation in herbivore communities change along nutrient availability gradients that affect plant biomass and community composition. Understanding how interspecific interactions may change in strength and direction along environmental gradients is important to predict how the diversity and structure of communities may respond to the introduction or removal of herbivore species in ecosystems.
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Affiliation(s)
- Elisabeth S Bakker
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands.
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Dangles O, Herrera M, Mazoyer C, Silvain JF. Temperature-dependent shifts in herbivore performance and interactions drive nonlinear changes in crop damages. GLOBAL CHANGE BIOLOGY 2013; 19:1056-1063. [PMID: 23504883 DOI: 10.1111/gcb.12104] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 11/13/2012] [Accepted: 11/21/2012] [Indexed: 06/01/2023]
Abstract
Understanding how and to what extent the influence of temperature on physiological performance scales up to interspecific interactions and process rate patterns remains a major scientific challenge faced by ecologists. Here, we combined approaches developed by two conceptual frameworks in ecology, the stress-gradient hypothesis (SGH), and the biodiversity-ecosystem functioning relationship (B-EF), to test the hypothesis that interspecific difference in thermal performance modulates multiple species interactions along a thermal stress (SGH) and the subsequent richness effects on process rates (B-EF). We designed an experiment using three species of herbivorous agricultural pests with different thermal optima for which we determined how temperature influences the direction and the strength of interaction and subsequent richness effects on crop damage (7 species interaction treatments × 6 temperature treatments × 10 replicates). We showed that both biotic interactions and species richness effects drive variations in crop damages along a thermal stress gradient, and thus have the potential to drive agro-system responses to climate change. To help explain and generalize underlying mechanisms of richness effects on process rates, we further proposed a conceptual model that views interaction outcomes as shifting between positive and negative along a thermal stress depending on species thermal optima. Overall, our study demonstrates that nonlinear effects of temperature on process rates must be a major concern in terms of prediction and management of the consequences of global warming.
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Affiliation(s)
- Olivier Dangles
- Institut de Recherche pour le Développement, Gif-sur-Yvette, Cedex, France.
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Li H, Colica G, Wu PP, Li D, Rossi F, De Philippis R, Liu Y. Shifting species interaction in soil microbial community and its influence on ecosystem functions modulating. MICROBIAL ECOLOGY 2013; 65:700-8. [PMID: 23299348 DOI: 10.1007/s00248-012-0171-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 12/17/2012] [Indexed: 05/07/2023]
Abstract
The supportive and negative evidence for the stress gradient hypothesis (SGH) led to an ongoing debate among ecologists and called for new empirical and theoretical work. In this study, we took various biological soil crust (BSCs) samples along a spatial gradient with four environmental stress levels to examine the fitness of SGH in microbial interactions and evaluate its influence on biodiversity-function relationships in BSCs. A new assessment method of species interactions within hard-cultured invisible soil community was employed, directly based on denaturing gradient gel electrophoresis fingerprint images. The results showed that biotic interactions in soil phototroph community dramatically shifted from facilitation to dominant competition with the improvement of microhabitats. It offered new evidence, which presented a different perspective on the hypothesis that the relative importance of facilitation and competition varies inversely along the gradient of abiotic stress. The path analysis indicated that influence of biotic interactions (r = 0.19, p < 0.05) on ecosystem functions is lower than other community properties (r = 0.62, p < 0.001), including soil moisture, crust coverage, and biodiversity. Furthermore, the correlation between species interactions and community properties was non-significant with low negative influence (r = -0.27, p > 0.05). We demonstrate that the inversion of biotic interaction as a response to the gradient of abiotic stresses existed not only in the visible plant community but also in the soil microbial community.
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Affiliation(s)
- Hua Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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