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Firmino Carvalho-Roel C, Iannini-Custódio AE, Marçal Júnior O, Grilo C. The spatial, climatic and temporal factors influencing roadkill change according to the taxonomic level. J Environ Manage 2023; 348:119221. [PMID: 37913600 DOI: 10.1016/j.jenvman.2023.119221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/27/2023] [Accepted: 10/02/2023] [Indexed: 11/03/2023]
Abstract
Roads are the second largest anthropogenic cause of mortality for most vertebrates. Previous research has analyzed the factors influencing roadkill either by species or by group of species based on some species-specific characteristics. However, to gain a comprehensive understanding on the consistency of findings within and between taxa, it is necessary to conduct an analysis that encompasses both individual species and group of species. This study aims to assess the role of taxonomic level in determining the spatial, climatic and temporal drivers using roadkill data for 70 species. We used generalized linear models to examine the association between roadkill and land cover and climate across 26 individual species and groups of reptiles, birds and mammals. Temporal patterns were evaluated using circular statistics. Our study revealed variations in spatial, climatic and temporal factors among taxa. For reptiles, spatial patterns differed between the class/order and species level, while climatic and temporal patterns remained consistent among these taxonomic levels. Spatial and climatic patterns were not consistent between class, order and associated species for birds and mammals. Temporal patterns, on the other hand, were consistent between each order and its associated species. In general, we found that roadkill incidence was positively associated with silviculture and agriculture cover as well as proximity of rivers. Accumulated insolation and mean minimum temperature were positively associated with roadkill, while mean temperature exhibited a negative association. Our study emphasizes the importance of analyzing roadkill variables on a species-specific basis. In the case of endangered species with low roadkill rates, it is essential to consider their assessment alongside other species exhibiting similar behavior and ecological needs.
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Affiliation(s)
- Carine Firmino Carvalho-Roel
- Instituto de Biologia, Universidade Federal de Uberlândia, Rua Ceará (esquina com rua Amazonas), s/n, Bairro Umuarama, Uberlândia, Minas Gerais, 38405-302, Brasil; Programa de Pós-graduação em Ecologia, Conservação e Biodiversidade, Universidade Federal de Uberlândia, Rua Ceará, 1084, Uberlândia, Minas Gerais, 38405-240, Brasil.
| | - Ana Elizabeth Iannini-Custódio
- Instituto de Biologia, Universidade Federal de Uberlândia, Rua Ceará (esquina com rua Amazonas), s/n, Bairro Umuarama, Uberlândia, Minas Gerais, 38405-302, Brasil
| | - Oswaldo Marçal Júnior
- Instituto de Biologia, Universidade Federal de Uberlândia, Rua Ceará (esquina com rua Amazonas), s/n, Bairro Umuarama, Uberlândia, Minas Gerais, 38405-302, Brasil; Programa de Pós-graduação em Ecologia, Conservação e Biodiversidade, Universidade Federal de Uberlândia, Rua Ceará, 1084, Uberlândia, Minas Gerais, 38405-240, Brasil
| | - Clara Grilo
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal; BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal; Setor Ecologia/Departamento de Biologia Universidade Federal de Lavras, 37200 000, Minas Gerais, Brazil
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Patterson D, Levin S, Staver AC, Touboul J. Pattern Formation in Mesic Savannas. Bull Math Biol 2023; 86:3. [PMID: 38010440 PMCID: PMC10682166 DOI: 10.1007/s11538-023-01231-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 10/29/2023] [Indexed: 11/29/2023]
Abstract
We analyze a spatially extended version of a well-known model of forest-savanna dynamics, which presents as a system of nonlinear partial integro-differential equations, and study necessary conditions for pattern-forming bifurcations. Homogeneous solutions dominate the dynamics of the standard forest-savanna model, regardless of the length scales of the various spatial processes considered. However, several different pattern-forming scenarios are possible upon including spatial resource limitation, such as competition for water, soil nutrients, or herbivory effects. Using numerical simulations and continuation, we study the nature of the resulting patterns as a function of system parameters and length scales, uncovering subcritical pattern-forming bifurcations and observing significant regions of multistability for realistic parameter regimes. Finally, we discuss our results in the context of extant savanna-forest modeling efforts and highlight ongoing challenges in building a unifying mathematical model for savannas across different rainfall levels.
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Affiliation(s)
- Denis Patterson
- High Meadows Environmental Institute, Princeton University, Princeton, NJ, 08544, USA.
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA.
- Department of Mathematical Sciences, Durham University, Durham, UK.
| | - Simon Levin
- High Meadows Environmental Institute, Princeton University, Princeton, NJ, 08544, USA
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Ann Carla Staver
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
- Yale Institute for Biospheric Studies, Yale University, New Haven, CT, 06520, USA
| | - Jonathan Touboul
- Department of Mathematics, Brandeis University, Waltham, MA, 02453, USA
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, 02453, USA
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Silva-Souza KJ, Pivato MG, Silva VC, Haidar RF, Souza AF. New patterns of the tree beta diversity and its determinants in the largest savanna and wetland biomes of South America. Plant Divers 2023; 45:369-384. [PMID: 37601544 PMCID: PMC10435914 DOI: 10.1016/j.pld.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 08/22/2023]
Abstract
Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation. Here we used occurrence and abundance data in combination with objective analytical methods to propose two bioregionalization schemes for tree species of the Cerrado and the Pantanal in South America. We also evaluated the contribution of three sets of determinants of the occurrence- and abundance-based subregions. We compiled data on tree species composition from 894 local assemblages based on species occurrences, and from 658 local assemblages based on species abundances. We used an unconstrained community-level modelling approach and clustering techniques to identify and map tree subregions for the occurrence and the abundance data sets, separately. Hierarchical clustering analyses were conducted to investigate floristic affinities between the subregions and to map broader floristic regions. We used multinomial logistic regression models, deviance partitioning, and rank-sum tests to assess the main subregion correlates. We identified 18 occurrence- and four abundance-based subregions in the Cerrado-Pantanal. The hierarchical classifications grouped the occurrence-based subregions into nine floristic zones and abundance-based subregions into two broad floristic zones. Variation in subregions were explained mainly by environmental factors and spatial structure in both occurrence and abundance data sets. The occurrence- and abundance-based subregions are complementary approaches to disentangle macroecological patterns and to plan conservation efforts in the Cerrado and the Pantanal. Our findings based on occurrence data revealed more complex and interdigitated boundaries between subregions of tree species than previously reported. The environment, historical stability, and human effects act in a synergetic way on the distribution of the subregions. Finally, the relevance of contemporary environmental factors to the subregion patterns we found alert us to the profound impact global warming may have on the spatial organization of the Cerrado-Pantanal tree flora.
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Affiliation(s)
| | - Maíra G. Pivato
- Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, RN, Brazil
| | - Vinícius C. Silva
- Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, RN, Brazil
| | - Ricardo F. Haidar
- Curso de Engenharia Ambiental, Universidade Federal do Tocantins, TO, Brazil
| | - Alexandre F. Souza
- Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, RN, Brazil
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Muraina TO, Asenso Barnieh B, Jimoh SO, Olasupo IO, Bello SK, Usman S, Mudzengi CP, NourEldeen N, Abdul Aziz A, Anibaba QA. Grassland cover declined in Southern Africa but increased in other African subcontinents in early twenty-first century. Environ Monit Assess 2023; 195:621. [PMID: 37106260 DOI: 10.1007/s10661-023-11160-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/22/2023] [Indexed: 05/19/2023]
Abstract
The African continent has the most extensive grassland cover in the world, providing valuable ecosystem services. African grasslands, like other continental grasslands, are prone to various anthropogenic disturbances and climate, and require data-driven monitoring for efficient functioning and service delivery. Yet, knowledge of how the African grassland cover has changed in the past years is lacking, especially at the subcontinent level, due to lack of relevant long-term, Africa-wide observations and experiments. In this study, we used Moderate Resolution Imaging Spectroradiometer (MODIS) Land Cover Type (MCD12Q1) data spanning 2001 to 2017 to conduct land use land cover (LULC) change analyses and map grassland distribution in Africa. Specifically, we assessed the changes in grassland cover across and within African subcontinents over three periods (2001-2013, 2013-2017, and 2001-2017). We found that the African grassland cover was 16,777,765.5 km2, 16,999,468.25 km2, and 16,968,304.25 km2 in 2001, 2013, and 2017, respectively. There were net gain (1.32%) and net loss (- 0.19%) during 2001-2013 and 2013-2017 periods, respectively, and the annual rate of change during these periods were 0.11% and - 0.05%, respectively. Generally, the African grassland cover increased by 1.14% (0.07% per annum) over the entire study period (2001-2017) at the expense of forestland, cropland, and built-up areas. The East and West African grassland cover reduced by 0.07% (- 0.02% per annum) and 1.35% (- 0.34% per annum), respectively from 2013 to 2017 but increased in other periods. On the other hand, the grassland cover in North and Central Africa increased throughout the three periods while that of Southern Africa decreased over the three periods. Overall, the net gains in the grassland cover of other African subcontinents offset the loss in Southern Africa and promoted the overall gain across Africa. This study underscores the need for continuous monitoring of African grasslands and the causes of their changes for efficient delivery of ecosystem services.
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Affiliation(s)
- Taofeek O Muraina
- Department of Animal Health and Production, Oyo State College of Agriculture and Technology, P.M.B. 10, Igbo-Ora, Oyo State, Nigeria.
- Agriculture Research Group, Organization of African Academic Doctors, Off Kamiti Road, P.O Box 25305-00100, Nairobi, Kenya.
| | - Beatrice Asenso Barnieh
- Agriculture Research Group, Organization of African Academic Doctors, Off Kamiti Road, P.O Box 25305-00100, Nairobi, Kenya.
- Earth Observation Research and Innovation Centre (EORIC), University of Energy and Natural Resources, P. O. Box 214, Sunyani, Ghana.
| | - Saheed O Jimoh
- Agriculture Research Group, Organization of African Academic Doctors, Off Kamiti Road, P.O Box 25305-00100, Nairobi, Kenya
- Department of Botany, University of Wyoming, Laramie, Wyoming, USA
- Leadvert Limited, Abeokuta, 110124, Ogun State, Nigeria
| | - Ibraheem O Olasupo
- Agriculture Research Group, Organization of African Academic Doctors, Off Kamiti Road, P.O Box 25305-00100, Nairobi, Kenya
- Department of Crop Science, Sule Lamido University, Jigawa State, PMB 048, Kafin Hausa, Nigeria
| | - Suleiman K Bello
- Department of Arid Land Agriculture, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, 80200, Kingdom of Saudi Arabia
- Department of Soil Science, Faculty of Agriculture/Institute for Agricultural Research, Ahmadu Bello University, P.M.B. 1044, Zaria, Kaduna State, Nigeria
| | - Samaila Usman
- Agriculture Research Group, Organization of African Academic Doctors, Off Kamiti Road, P.O Box 25305-00100, Nairobi, Kenya
- College of Grassland, Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Clarice P Mudzengi
- Department of Livestock, Wildlife and Fisheries, Gary Magadzire School of Agriculture, Great Zimbabwe University, Masvingo, Zimbabwe
| | - Nusseiba NourEldeen
- Institute of Economics, Economic and Social Research Bureau, Khartoum, 11111, Sudan
| | - Ammar Abdul Aziz
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, Australia
| | - Quadri A Anibaba
- Department of Ecology, Institute of Dendrology, Polish Academy of Sciences, Kornik, Poland
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Righi CA, de Oliveira Risante AP, Packer AP, do Couto HTZ. Biodiversity and biomass relationships in a cerrado stricto sensu in Southeastern Brazil. Environ Monit Assess 2023; 195:492. [PMID: 36943528 DOI: 10.1007/s10661-023-11051-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Deforestation accounts for the majority of greenhouse gas emissions in developing countries. In Brazil, deforestation represents ~ 70% of the nation's greenhouse gas emissions. Among the main deforested vegetation, Cerrado (Brazilian savanna) occupies a prominent position as it is the second biggest biome in Brazil. Despite its importance, there are still few estimates of above and belowground biomass of Cerrado vegetation encompassing its structural and spatial complexity. Also, Cerrado holds a specific biodiversity that is normally undervalued and which is being lost in the fires of agricultural fronts. In this context, this study aimed to verify the relationship of the existing flora biodiversity in a cerrado stricto sensu with its aboveground biomass and carbon stocks. The possibility of a relationship between fine root mass and soil organic carbon content was also verified. The study area presented a total of 67 species and 798 trees (average: 1596 trees ha-1). The mean total aboveground biomass and carbon stocks were 77.08 Mg ha-1 and 38.54 Mg ha-1 respectively. Soil organic carbon stock (0-30 cm) was 8.51 Mg ha-1 whereas fine roots were 1.637 Mg ha-1. Total aboveground biomass presented a highly significant asymptotic relationship with biodiversity demonstrating its importance in reaching high biomass accumulation. A significant relationship between soil organic carbon content and fine root biomass was found making easier belowground biomass estimates.
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Affiliation(s)
- Ciro Abbud Righi
- Department of Forestry Science, Escola Superior de Agricultura "Luiz de Queiroz,", University of São Paulo, Av. Pádua Dias, 11, P. O. Box 09, CEP 13418-900, Piracicaba, São Paulo, Brazil.
| | - Ana Paula de Oliveira Risante
- Department of Forestry Science, Escola Superior de Agricultura "Luiz de Queiroz,", University of São Paulo, Av. Pádua Dias, 11, P. O. Box 09, CEP 13418-900, Piracicaba, São Paulo, Brazil
| | - Ana Paula Packer
- Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), Embrapa Meio-Ambiente, Ministério da Agricultura, Pecuária e Abastecimento, Rodovia SP-340 - Km 127.5Tanquinho Velho, P. O. Box 69, CEP 13820-000, Jaguariúna, São Paulo, Brazil
| | - Hilton Thadeu Zarate do Couto
- Department of Forestry Science, Escola Superior de Agricultura "Luiz de Queiroz,", University of São Paulo, Av. Pádua Dias, 11, P. O. Box 09, CEP 13418-900, Piracicaba, São Paulo, Brazil
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Yeboah SO, Nasare LI, Abunyewa AA. Effect of landuse on floristic composition and diversity of medicinal plants in the Guinea Savanna zone of Ghana. Heliyon 2022; 8:e10203. [PMID: 36042738 PMCID: PMC9420379 DOI: 10.1016/j.heliyon.2022.e10203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/05/2022] [Accepted: 08/04/2022] [Indexed: 11/19/2022] Open
Abstract
The use of medicinal plants is the most accessible primary health care approach in rural communities with limited infrastructure for western medicine. Medicinal plants are therefore an integral component of traditional medicine in Ghana, but wild bushes where medicinal plants regenerate naturally are being converted to alternative landuse. Although most landuse changes are destructive to biodiversity, some indigenous land use systems are known to be environmentally friendly. The present study examined the diversity and abundance of medicinal plants in three landuse types (Protected Area, Fallow land and Farmland) of northern Ghana. Twenty-five quadrates of 30 × 30 m were randomly laid in each landuse and replicated in three communities. Leguminosae, Combretaceae and Rubiaceae occurred as the most dominant medicinal plant families in all landuse but woody plants were significantly abundant in protected areas (p = 0.001). Species richness, Shannon diversity index, alpha and gamma diversities were all higher in the protected areas. Species composition also varied between landuse in beta diversity (p = 0.005, r2 = 0.33). Medicinal plant population have reduced significantly in farmlands, farmers should therefore adopt agroforestry practices to help conserve medicinal plant biodiversity.
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Affiliation(s)
- Samuel Owusu Yeboah
- Graduate School, University for Development Studies, P. O. Box TL 1882, Tamale, Ghana
| | - Latif Iddrisu Nasare
- Faculty of Natural Resources and Environment, University for Development Studies, Tamale, Ghana
- Corresponding author.
| | - Akwasi Adutwum Abunyewa
- College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
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Liu L, Yang J, Cao M, Song Q. Intraspecific trait variation of woody species reduced in a savanna community, southwest China. Plant Divers 2022; 44:163-169. [PMID: 35505985 PMCID: PMC9043304 DOI: 10.1016/j.pld.2021.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/28/2021] [Accepted: 06/07/2021] [Indexed: 06/14/2023]
Abstract
Plants deploy various ecological strategies in response to environmental heterogeneity. In many forest ecosystems, plants have been reported to have notable inter- and intra-specific trait variation, as well as clear phylogenetic signals, indicating that these species possess a degree of phenotypic plasticity to cope with habitat variation in the community. Savanna communities, however, grow in an open canopy structure and exhibit little species diversification, likely as a result of strong environmental stress. In this study, we hypothesized that the phylogenetic signals of savanna species would be weak, the intraspecific trait variation (ITV) would be low, and the contribution of intraspecific variation to total trait variance would be reduced, owing to low species richness, multiple stresses and relatively homogenous community structure. To test these hypotheses, we sampled dominant woody species in a dry-hot savanna in southwestern China, focusing on leaf traits related to adaptability of plants to harsh conditions (year-round intense radiation, low soil fertility and seasonal droughts). We found weak phylogenetic signals in leaf traits and low ITV (at both individual and canopy-layer levels). Intraspecific variation (including leaf-, layer- and individual-scales) contributed little to the total trait variance, whereas interspecific variation and variation in leaf phenology explained substantial variance. Our study suggests that intraspecific trait variation is reduced in savanna community. Furthermore, our findings indicate that classifying species by leaf phenology may help better understand how species coexist under similar habitats with strong stresses.
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Affiliation(s)
- Lubing Liu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Min Cao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Qinghai Song
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
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Franco W, Vasconcelos HL, Feitosa RM. Patterns of Ant Diversity in the Natural Grasslands of Southern Brazil. Neotrop Entomol 2021; 50:725-735. [PMID: 34125403 DOI: 10.1007/s13744-021-00886-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
In the south of Brazil, grasslands are naturally widespread over two different biomes, the Pampa in the southernmost region and within the Atlantic Forest in the northern portions. The natural grasslands of the state of Paraná comprise a very particular physiognomy composed of two distinct formations: the Campos Gerais and the grasslands of the southwest. The first is located in the edge of the second plateau of Paraná state, comprising a great diversity of environments. The grasslands of the southwest are more homogeneous, with a continuous herbaceous stratum dominating the landscape. In this context, the aim of this study was to evaluate the patterns of species richness and composition of ants, an ecologically prominent group, along the natural grasslands of Paraná. We also intended to compare the faunal similarity between the two different grassland formations. For that, four different Conservation Unities were sampled along a latitudinal gradient. A remarkable total of 245 ant species was recorded, and the results indicate that species richness decreases as latitude increases along the grasslands of Paraná. There were clear differences in species composition between these two grasslands formations, given the significative number of endemic species in each of these two grassland formations. Ten species were recorded for the first time in the state of Paraná, of which three also for the first time in the Southern Region of Brazil. Overall, our study contributes to a better understanding about the diversity and composition of ant communities in subtropical grasslands.
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Affiliation(s)
- Weslly Franco
- Depto de Zoologia, Univ Federal do Paraná (UFPR), Curitiba, PR, Brazil.
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Hoyer-Leitzel A, Iams S. Impulsive Fire Disturbance in a Savanna Model: Tree-Grass Coexistence States, Multiple Stable System States, and Resilience. Bull Math Biol 2021; 83:113. [PMID: 34591211 PMCID: PMC8484106 DOI: 10.1007/s11538-021-00944-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/10/2021] [Indexed: 11/30/2022]
Abstract
Savanna ecosystems are shaped by the frequency and intensity of regular fires. We model savannas via an ordinary differential equation (ODE) encoding a one-sided inhibitory Lotka-Volterra interaction between trees and grass. By applying fire as a discrete disturbance, we create an impulsive dynamical system that allows us to identify the impact of variation in fire frequency and intensity. The model exhibits three different bistability regimes: between savanna and grassland; two savanna states; and savanna and woodland. The impulsive model reveals rich bifurcation structures in response to changes in fire intensity and frequency-structures that are largely invisible to analogous ODE models with continuous fire. In addition, by using the amount of grass as an example of a socially valued function of the system state, we examine the resilience of the social value to different disturbance regimes. We find that large transitions ("tipping") in the valued quantity can be triggered by small changes in disturbance regime.
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Affiliation(s)
- Alanna Hoyer-Leitzel
- Department of Mathematics and Statistics, Mount Holyoke College, 50 College Street, South Hadley, MA, 01075, USA.
| | - Sarah Iams
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
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Vermeire ML, Thoresen J, Lennard K, Vikram S, Kirkman K, Swemmer AM, Te Beest M, Siebert F, Gordijn P, Venter Z, Brunel C, Wolfaard G, Krumins JA, Cramer MD, Hawkins HJ. Fire and herbivory drive fungal and bacterial communities through distinct above- and belowground mechanisms. Sci Total Environ 2021; 785:147189. [PMID: 33933764 DOI: 10.1016/j.scitotenv.2021.147189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 04/07/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
Fire and herbivory are important natural disturbances in grassy biomes. Both drivers are likely to influence belowground microbial communities but no studies have unravelled the long-term impact of both fire and herbivory on bacterial and fungal communities. We hypothesized that soil bacterial communities change through disturbance-induced shifts in soil properties (e.g. pH, nutrients) while soil fungal communities change through vegetation modification (biomass and species composition). To test these ideas, we characterised soil physico-chemical properties (pH, acidity, C, N, P and exchangeable cations content, texture, bulk density, moisture), plant species richness and biomass, microbial biomass and bacterial and fungal community composition and diversity (using 16S and ITS rRNA amplicon sequencing, respectively) in six long-term (18 to 70 years) ecological research sites in South African savanna and grassland ecosystems. We found that fire and herbivory regimes profoundly modified soil physico-chemical properties, plant species richness and standing biomass. In all sites, an increase in woody biomass (ranging from 12 to 50%) was observed when natural disturbances were excluded. The intensity and direction of changes in soil properties were highly dependent on the topo-pedo-climatic context. Overall, fire and herbivory shaped bacterial and fungal communities through distinct driving forces: edaphic properties (including Mg, pH, Ca) for bacteria, and vegetation (herbaceous biomass and woody cover) for fungi. Fire and herbivory explained on average 7.5 and 9.8% of the fungal community variability, respectively, compared to 6.0 and 5.6% for bacteria. The relatively small changes in microbial communities due to natural disturbance is in stark contrast to dramatic vegetation and edaphic changes and suggests that soil microbial communities, having evolved with disturbance, are resistant to change. This represents both a buffer to short-term anthropogenic-induced changes and a restoration challenge in the face of long-term changes.
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Affiliation(s)
- M-L Vermeire
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa; IRD, CIRAD, University of Montpellier, PHIM, Montpellier, France.
| | - J Thoresen
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
| | - K Lennard
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, University of Cape Town, Cape Town, South Africa
| | - S Vikram
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Lynnwood Road, Hatfield, Pretoria, South Africa
| | - K Kirkman
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - A M Swemmer
- South African Environmental Observation Network (SAEON), Phalaborwa, South Africa
| | - M Te Beest
- Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, the Netherlands; Centre for African Conservation Ecology, Nelson Mandela University, Port Elizabeth 6031, South Africa; South African Environmental Observation Network, Grasslands-Forests-Wetlands Node, Montrose 3201, South Africa
| | - F Siebert
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - P Gordijn
- South African Environmental Observation Network, Grasslands-Forests-Wetlands Node, Montrose 3201, South Africa
| | - Z Venter
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa; Department of Terrestrial Ecology, Norwegian Institute for Nature Research, Trondheim, Norway (present affiliation)
| | - C Brunel
- IRD, CIRAD, University of Montpellier, PHIM, Montpellier, France
| | - G Wolfaard
- Sustineri Ecological Consulting (Pty) Ltd., Mbombela 1200, South Africa
| | - J A Krumins
- Department of Biology, Montclair State University, Montclair, NJ, USA
| | - M D Cramer
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
| | - H-J Hawkins
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa; Conservation South Africa, 301 Heritage House, Claremont 7375, South Africa
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11
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Scogings PF, Demmer S, Hattas D. Spinescence and Total Phenolic Content Do Not Influence Diet Preference of a Critically Endangered Megaherbivore, but the Mix of Compounds Does. J Chem Ecol 2021; 47:322-333. [PMID: 33651225 DOI: 10.1007/s10886-021-01258-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 11/30/2022]
Abstract
In contrast to understanding spinescence in savanna woody species, little is known about the functions of plant secondary metabolites (PSM). Negative effects of PSMs on individual animal performance potentially translate into negative effects on herbivore population growth. Hence, understanding PSM functions is important for the conservation of savanna megafauna. We tested the view that black rhinoceros (Diceros bicornis) diet preference is not affected by spinescence or total phenolic abundance. We hypothesized that the composition of phenolic mixtures, however, would affect preference. Furthermore, we tested our data from 71 woody species for a trade-off between structural and chemical defenses. Spinescence type, and spinescence generally, did not deter black rhino feeding. Using eco-metabolomic data, we found that total abundance of phenolics did not affect preference, but mixture composition did and that the probability of spinescence trading off against phenolics depended on the mixture. We note that our study was restricted to black rhino and that diet preferences of other mammal herbivores might be influenced by subtle differences in phenolic mixtures. However, our results did support a previous, more detailed study of phenolic profiles of six species showing the same patterns in relation to preference generalised across mammal herbivore species in savannas. Our results represent substantial advancement in the understanding of the roles of PSMs, especially flavonoid compounds, in the functioning of savanna ecosystems, and highlight the need to dig deeper into broad groups of traits such as spinescence or total phenolics to improve understanding of woody plant defenses in savannas.
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Affiliation(s)
- Peter F Scogings
- School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa.
| | - Stuart Demmer
- School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa.,Centre for Functional Biodiversity, University of KwaZulu-Natal, Scottsville, South Africa
| | - Dawood Hattas
- Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa
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12
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Newberry BM, Power CR, Abreu RCR, Durigan G, Rossatto DR, Hoffmann WA. Flammability thresholds or flammability gradients? Determinants of fire across savanna-forest transitions. New Phytol 2020; 228:910-921. [PMID: 33410161 DOI: 10.1111/nph.16742] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 06/01/2020] [Indexed: 06/12/2023]
Abstract
Vegetation-fire feedbacks are important for determining the distribution of forest and savanna. To understand how vegetation structure controls these feedbacks, we quantified flammability across gradients of tree density from grassland to forest in the Brazilian Cerrado. We experimentally burned 102 plots, for which we measured vegetation structure, fuels, microclimate, ignition success and fire behavior. Tree density had strong negative effects on ignition success, rate of spread, fire-line intensity and flame height. Declining grass biomass was the principal cause of this decline in flammability as tree density increased, but increasing fuel moisture contributed. Although the response of flammability to tree cover often is portrayed as an abrupt, largely invariant threshold, we found the response to be gradual, with considerable variability driven largely by temporal changes in atmospheric humidity. Even when accounting for humidity, flammability at intermediate tree densities cannot be predicted reliably. Fire spread in savanna-forest mosaics is not as deterministic as often assumed, but may appear so where vegetation boundaries are already sharp. Where transitions are diffuse, fire spread is difficult to predict, but should become increasingly predictable over multiple fire cycles, as boundaries are progressively sharpened until flammability appears to respond in a threshold-like manner.
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Affiliation(s)
- Brooklynn M Newberry
- Department of Plant and Microbial Biology, North Carolina State University, Campus Box 7612, Raleigh, NC, 27695, USA
| | - Collin R Power
- Department of Fisheries, Wildlife, and Conservation Biology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Rodolfo C R Abreu
- Department of Plant and Microbial Biology, North Carolina State University, Campus Box 7612, Raleigh, NC, 27695, USA
- Departamento de Ciências Ambientais, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, CEP 23897-000, Brazil
| | - Giselda Durigan
- Laboratório de Ecologia e Hidrologia Florestal, Floresta Estadual de Assis, Instituto Florestal, Assis, SP, 19802-970, Brazil
| | - Davi R Rossatto
- Departamento de Biologia, Universidade Estadual Paulista (UNESP), Campus de Jaboticabal, Jaboticabal, SP, 14884-900, Brazil
| | - William A Hoffmann
- Department of Plant and Microbial Biology, North Carolina State University, Campus Box 7612, Raleigh, NC, 27695, USA
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13
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Ganamé M, Bayen P, Dimobe K, Ouédraogo I, Thiombiano A. Aboveground biomass allocation, additive biomass and carbon sequestration models for Pterocarpus erinaceus Poir. in Burkina Faso. Heliyon 2020; 6:e03805. [PMID: 32368649 PMCID: PMC7184175 DOI: 10.1016/j.heliyon.2020.e03805] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/12/2020] [Accepted: 04/15/2020] [Indexed: 11/19/2022] Open
Abstract
Efforts to develop allometric models for accurate estimation of biomass and carbon sequestration in Sub-Saharan African savanna ecosystems remain inconclusive. Most available allometric models are not site-specific, and hence do not account for the effects of regional climate variabilities on tree growth and capacity to sequester carbon. In contrast, site-specific biomass allometric models constitute a robust tool for forest and carbon emission management in the context of the reducing emissions from deforestation and degradation program (REDD+). Although site-specific models have been developed for several tropical tree species, such models do not exist for Pterocarpus erinaceus in Burkina Faso. In this study, we investigated biomass fraction patterns and used a system of additive allometric models for predicting aboveground biomass and carbon stocks of P. erinaceus components. Thirty P. erinaceus trees were destructively sampled to estimate the biomass of their stems, branches and leaves. The biomass fraction of each component was assessed and its relationship with tree diameter at breast height (dbh) examined. The best allometric equations of the tree components, selected from three non-linear models with dbh, height (ht) and crown diameter (Cd) as predictors, were combined to develop an additive allometric model, using the Seemingly Unrelated Regressions (SUR) method. The Ash method was then used to estimate the carbon content of the different components. Leaf and stem biomass fractions decreased when the dbh increased, whereas a reverse trend was observed for branch biomass. Dbh was the most correlated independent variable with all biomass components. AGB = e−3.46(dbh)1.62+e−2.45(dbh)2.31+e−2.68(dbh) was the most appropriate additive allometric equation for estimating the biomass of P. erinaceus trees. The carbon content of the leaves, branches and stems was 55.73%, 56.68% and 56.23%, respectively. The developed allometric equations can be used to accurately estimate the aboveground biomass of P. erinaceus in the savannas of Burkina Faso and other similar ecosystems in Sub-Saharan Africa.
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Affiliation(s)
- Moussa Ganamé
- Laboratory of Plant Biology and Ecology, University Joseph KI-ZERBO, 03 BP 7021 Ouagadougou 03, Burkina Faso
- Corresponding author.
| | - Philippe Bayen
- Laboratory of Plant Biology and Ecology, University Joseph KI-ZERBO, 03 BP 7021 Ouagadougou 03, Burkina Faso
- University of Dédougou, Burkina Faso
| | - Kangbéni Dimobe
- Laboratory of Plant Biology and Ecology, University Joseph KI-ZERBO, 03 BP 7021 Ouagadougou 03, Burkina Faso
- University of Dédougou, Burkina Faso
- West African Science Service Centre on Climate Change and Adapted Land Use (WASCAL), Competence Centre, 06 BP 9507 Ouagadougou 06, Burkina Faso
| | - Issaka Ouédraogo
- Laboratory of Plant Biology and Ecology, University Joseph KI-ZERBO, 03 BP 7021 Ouagadougou 03, Burkina Faso
- Department of Life and Earth Sciences, Institute of Sciences (IDS), Ouagadougou, Burkina Faso
| | - Adjima Thiombiano
- Laboratory of Plant Biology and Ecology, University Joseph KI-ZERBO, 03 BP 7021 Ouagadougou 03, Burkina Faso
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14
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Silveira Miranda JE, de Melo FR, Keichi Umetsu R. Are Roadkill Hotspots in the Cerrado Equal Among Groups of Vertebrates? Environ Manage 2020; 65:565-573. [PMID: 32060629 DOI: 10.1007/s00267-020-01263-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
Understand the spatial distribution of wildlife roadkill is necessary to design mitigation measures minimizing damage to the fauna and the human population. Thus, we aimed to analyze the spatial distribution of wildlife roadkill in the Brazilian savanna ("Cerrado") to test whether roadkill hotspots match between the studied animal groups. We collected data of wildlife roadkill over a year in the southwest region of the state of Goiás, Brazil. To understand the distribution of roadkill on highways and to identify the aggregation hotspots, we used the modified two-dimensional Ripley K test and the two-dimensional hotspot identification analysis. We detected that birds and mammals have different aggregation points. These points may vary when the two groups are analyzed together or when species with greater abundance are removed from the analyses. Hence, we concluded that using generalist approaches including several species, are not enough, and can lead to erroneous conclusions. Therefore, it is necessary that the analyses be done in groups.
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Affiliation(s)
- Jefferson Eduardo Silveira Miranda
- Postgraduate Program in Ecology and Conservation, State University of Mato Grosso, Nova Xavantina, Mato Grosso, Brazil.
- Faculdade de Iporá, FAI, Iporá, Goiás, Brazil.
| | - Fabiano Rodrigues de Melo
- Postgraduate Program in Ecology and Conservation, State University of Mato Grosso, Nova Xavantina, Mato Grosso, Brazil
- Associate Professor III, Department of Forest Engineering, Federal University of Viçosa (UFV), Viçosa, Minas Gerais, Brazil
- Muriqui Institute for Biodiversity, Caratinga, Minas Gerais, Brazil
- Brazilian Coordinator of the Primate Specialist Group, Species Survival Commission, Internation Union for Conservation of Nature (PSG/SSC/IUCN), Austin, USA
| | - Ricardo Keichi Umetsu
- Postgraduate Program in Ecology and Conservation, State University of Mato Grosso, Nova Xavantina, Mato Grosso, Brazil
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15
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Wingate VR, Phinn SR, Kuhn N. Mapping precipitation-corrected NDVI trends across Namibia. Sci Total Environ 2019; 684:96-112. [PMID: 31153083 DOI: 10.1016/j.scitotenv.2019.05.158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 05/09/2019] [Accepted: 05/11/2019] [Indexed: 06/09/2023]
Abstract
Savannas comprise a major component of the Earth system and contribute ecosystem services and functions essential to human livelihoods. Monitoring spatial and temporal trends in savanna vegetation and understanding change drivers is therefore crucial. Widespread greening has been identified across southern Africa; yet its drivers and manifestations on the ground remain ambiguous. This study removes the effects of precipitation on an NDVI time-series, thereby identifying trends not driven by rainfall. It utilizes the significant correlation between vegetation and precipitation as captured using MODIS and rainfall estimates. A linear regression between variables was used to derive its residual (corrected) time-series, and the rate and spatial extent of trends were evaluated in relation to biomes. A random sample-based qualitative interpretation of high spatial resolution imagery was then used to evaluate the nature of the trend on the ground. 23.25% of the country, including all biomes exhibited positive trends. We propose that greening may be related to a reduction in woody species richness, loss of the large trees and a shift towards drought tolerant shrub species, as has been shown in other sub-Saharan environments. 3.23% of the country exhibited negative trends, which were mostly associated with more humid (forested) regions pointing to deforestation as a cause; these manifested as vegetation clearing, identifiable using high resolution multi-temporal imagery. Greening trends could not be identified using this approach; instead, they point to the occurrence of gradual vegetation change caused by indirect drivers.
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Affiliation(s)
- Vladimir R Wingate
- Physical Geography and Environmental Change, University of Basel, Klingelbergstrasse 27, Basel 4056, Switzerland.
| | - Stuart R Phinn
- Remote Sensing Research Centre, School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Nikolaus Kuhn
- Physical Geography and Environmental Change, University of Basel, Klingelbergstrasse 27, Basel 4056, Switzerland.
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16
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Aghová T, Palupčíková K, Šumbera R, Frynta D, Lavrenchenko LA, Meheretu Y, Sádlová J, Votýpka J, Mbau JS, Modrý D, Bryja J. Multiple radiations of spiny mice (Rodentia: Acomys) in dry open habitats of Afro-Arabia: evidence from a multi-locus phylogeny. BMC Evol Biol 2019; 19:69. [PMID: 30832573 PMCID: PMC6399835 DOI: 10.1186/s12862-019-1380-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 02/01/2019] [Indexed: 01/02/2023] Open
Abstract
Background Spiny mice of the genus Acomys are distributed mainly in dry open habitats in Africa and the Middle East, and they are widely used as model taxa for various biological disciplines (e.g. ecology, physiology and evolutionary biology). Despite their importance, large distribution and abundance in local communities, the phylogeny and the species limits in the genus are poorly resolved, and this is especially true for sub-Saharan taxa. The main aims of this study are (1) to reconstruct phylogenetic relationships of Acomys based on the largest available multilocus dataset (700 genotyped individuals from 282 localities), (2) to identify the main biogeographical divides in the distribution of Acomys diversity in dry open habitats in Afro-Arabia, (3) to reconstruct the historical biogeography of the genus, and finally (4) to estimate the species richness of the genus by application of the phylogenetic species concept. Results The multilocus phylogeny based on four genetic markers shows presence of five major groups of Acomys called here subspinosus, spinosissimus, russatus, wilsoni and cahirinus groups. Three of these major groups (spinosissimus, wilsoni and cahirinus) are further sub-structured to phylogenetic lineages with predominantly parapatric distributions. Combination of alternative species delimitation methods suggests the existence of 26 molecular operational taxonomic units (MOTUs), potentially corresponding to separate species. The highest genetic diversity was found in Eastern Africa. The origin of the genus Acomys is dated to late Miocene (ca. 8.7 Ma), when the first split occurred between spiny mice of eastern (Somali-Masai) and south-eastern (Zambezian) savannas. Further diversification, mostly in Plio-Pleistocene, and the current distribution of Acomys were influenced by the interplay of global climatic factors (e.g., Messinian salinity crisis, intensification of Northern Hemisphere glaciation) with local geomorphology (mountain chains, aridity belts, water bodies). Combination of divergence dating, species distribution modelling and historical biogeography analysis suggests repeated “out-of-East-Africa” dispersal events into western Africa, the Mediterranean region and Arabia. Conclusions The genus Acomys is very suitable model for historical phylogeographic and biogeographic reconstructions of dry non-forested environments in Afro-Arabia. We provide the most thorough phylogenetic reconstruction of the genus and identify major factors that influenced its evolutionary history since the late Miocene. We also highlight the urgent need of integrative taxonomic revision of east African taxa. Electronic supplementary material The online version of this article (10.1186/s12862-019-1380-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- T Aghová
- Institute of Vertebrate Biology of the Czech Academy of Sciences, 603 65, Brno, Czech Republic. .,Department of Zoology, National Museum, 115 79, Prague, Czech Republic.
| | - K Palupčíková
- Department of Zoology, Faculty of Science, Charles University, 128 44, Prague, Czech Republic
| | - R Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
| | - D Frynta
- Department of Zoology, Faculty of Science, Charles University, 128 44, Prague, Czech Republic
| | - L A Lavrenchenko
- A. N. Severtsov Institute of Ecology and Evolution RAS, 119071, Moscow, Russia
| | - Y Meheretu
- Department of Biology and Institute of Mountain Research and Development, Mekelle University, P.O. Box 3102, Mekelle, Tigray, Ethiopia
| | - J Sádlová
- Department of Parasitology, Faculty of Science, Charles University, 128 44, Prague, Czech Republic
| | - J Votýpka
- Department of Parasitology, Faculty of Science, Charles University, 128 44, Prague, Czech Republic.,Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, 370 05, České Budějovice, Czech Republic
| | - J S Mbau
- Department of Land Resource Management and Agricultural Technology, College of Agriculture and Veterinary Sciences, University of Nairobi, Nairobi, Kenya
| | - D Modrý
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, 370 05, České Budějovice, Czech Republic.,Department of Pathology and Parasitology, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, 612 42, Brno, Czech Republic
| | - J Bryja
- Institute of Vertebrate Biology of the Czech Academy of Sciences, 603 65, Brno, Czech Republic.,Department of Botany and Zoology, Faculty of Science, Masaryk University, 602 00, Brno, Czech Republic
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17
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Mistry J, Schmidt IB, Eloy L, Bilbao B. New perspectives in fire management in South American savannas: The importance of intercultural governance. Ambio 2019; 48:172-179. [PMID: 29752682 PMCID: PMC6346601 DOI: 10.1007/s13280-018-1054-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 01/25/2018] [Accepted: 03/27/2018] [Indexed: 05/29/2023]
Abstract
Wildfires continue to cause damage to property, livelihoods and environments around the world. Acknowledging that dealing with wildfires has to go beyond fire-fighting, governments in countries with fire-prone ecosystems have begun to recognize the multiple perspectives of landscape burning and the need to engage with local communities and their practices. In this perspective, we outline the experiences of Brazil and Venezuela, two countries where fire management has been highly contested, but where there have been recent advances in fire management approaches. Success of these new initiatives have been measured by the reduction in wildfire extent through prescribed burning, and the opening of a dialogue on fire management between government agencies and local communities. Yet, it is clear that further developments in community participation need to take place in order to avoid the appropriation of local knowledge systems by institutions, and to better reflect more equitable fire governance.
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Affiliation(s)
- Jayalaxshmi Mistry
- Department of Geography, Royal Holloway University of London, Egham, Surrey TW200EX UK
| | - Isabel Belloni Schmidt
- Departamento de Ecologia, Universidade de Brasília, P.O. Box 04457, Brasília, DF CEP 70910-900 Brazil
| | - Ludivine Eloy
- National Center for Scientific Research (CNRS), UMR 5281 ART-DEV, Paul Valéry University, 34090 Montpellier, France
- Centro de Desenvolvimento Sustentável, Campus Universitário Darcy Ribeiro Gleba A Universidade de Brasília - Asa Norte, Brasília, DF 70910-900 Brazil
| | - Bibiana Bilbao
- Departamento de Estudios Ambientales, Universidad Simón Bolívar, Apartado 89000, Caracas, 1080 Venezuela
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18
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Laris P, Jo A, Wechsler SP. Effects of landscape pattern and vegetation type on the fire regime of a mesic savanna in Mali. J Environ Manage 2018; 227:134-145. [PMID: 30172932 DOI: 10.1016/j.jenvman.2018.08.091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/20/2018] [Accepted: 08/24/2018] [Indexed: 06/08/2023]
Abstract
Savanna fires are a critical earth-system process that alter vegetation regionally and contribute to changes in atmospheric composition globally. The fire regime in savannas has shifted over time resulting in a large reduction in burned area. Savanna fires, which are human caused and set for a plethora of reasons, produce complex mosaic burned area patterns that tend to result in lower overall burned area. Mosaic fire regimes are difficult to detect and map accurately using available satellite data. Imagery-induced low-resolution bias makes it difficult to link fires with relevant environmental and anthropogenic factors, while higher resolution imagery is temporally less frequent. We explore how landscape pattern affects the fire regime in a mesic savanna by quantifying relationships between the spatial patterns of vegetation, which are shaped by natural and human factors, widely used ecological indices, and the seasonality and frequency of fires. The study finds that landscape pattern influences the fire regime; fire seasonality and frequency varied by landscape index at both the vegetation class and landscape scales. Percent cover, shape index and largest patch landscape ecological indices demonstrated the most consistency in burn date trends across scales. The study finds that landscape fragmentation-specifically a reduction in the size of patches and an increase in their number-results in an earlier fire regime. We conclude that fire intensity and severity will continue to decline as agriculture expands and landscapes fragment from agriculture in savannas. Our methods also demonstrate the ability to integrate landscape indices with coarse-resolution fire data.
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Affiliation(s)
- Paul Laris
- Department of Geography, California State University Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840, USA.
| | - Aurahm Jo
- 1145 Northumberland Dr, Sunnyvale, CA 94087, USA
| | - Suzanne P Wechsler
- Department of Geography, California State University Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840, USA
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19
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Costa AN, Bruna EM, Vasconcelos HL. Do an ecosystem engineer and environmental gradient act independently or in concert to shape juvenile plant communities? Tests with the leaf-cutter ant Atta laevigata in a Neotropical savanna. PeerJ 2018; 6:e5612. [PMID: 30324010 PMCID: PMC6183508 DOI: 10.7717/peerj.5612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/14/2018] [Indexed: 11/20/2022] Open
Abstract
Background Ecosystem engineers are species that transform habitats in ways that influence other species.While the impacts of many engineers have been well described, our understanding of how their impact varies along environmental gradients remains limited. Although disentangling the effects of gradients and engineers on biodiversity is complicated-the gradients themselves can be altered by engineers-doing so is necessary to advance conceptual and mathematical models of ecosystem engineering. We used leaf-cutter ants (Atta spp.) to investigate the relative influence of gradients and environmental engineers on the abundance and species richness of woody plants. Methods We conducted our research in South America's Cerrado. With a survey of plant recruits along a canopy cover gradient, and data on environmental conditions that influence plant recruitment, we fit statistical models that addressed the following questions: (1) Does A. laevigata modify the gradient in canopy cover found in our Cerrado site? (2) Do environmental conditions that influence woody plant establishment in the Cerrado vary with canopy cover or proximity to A. laevigata nests? (3) Do A. laevigata and canopy cover act independently or in concert to influence recruit abundance and species richness? Results We found that environmental conditions previously shown to influence plant establishment in the Cerrado varied in concert with canopy cover, but that ants are not modifying the cover gradient or cover over nests. However, ants are modifying other local environmental conditions, and the magnitude and spatial extent of these changes are consistent across the gradient. In contrast to prior studies, we found that ant-related factors (e.g., proximity to nests, ant changes in surface conditions), rather than canopy cover, had the strongest effect on the abundance of plant recruits. However, the diversity of plants was influenced by both the engineer and the canopy cover gradient. Discussion Atta laevigata in the Cerrado modify local conditions in ways that have strong but spatially restricted consequences for plant communities. We hypothesize that ants indirectly reduce seedling establishment by clearing litter and reducing soil moisture, which leads to seed and seedling desiccation. Altering soil nutrients could also reduce juvenile growth and survivorship; if so these indirect negative effects of engineering could exacerbate their direct effects of harvesting plants. The effects of Atta appear restricted to nest mounds, but they could be long-lasting because mounds persist long after a colony has died or migrated. Our results support the hypothesis that leaf-cutter ants play a dominant role in Cerrado plant demography. We suggest the ecological and economic footprint of these engineers may increase dramatically in coming decades due to the transformation of the Cerrado by human activities.
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Affiliation(s)
- Alan N Costa
- Instituto de Biologia, Universidade Federal de Uberlândia, Uberlandia, Minas Gerais, Brazil
| | - Emilio M Bruna
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA.,Center for Latin American Studies, University of Florida, Gainesville, FL, USA
| | - Heraldo L Vasconcelos
- Instituto de Biologia, Universidade Federal de Uberlândia, Uberlandia, Minas Gerais, Brazil
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20
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Githumbi EN, Courtney Mustaphi CJ, Yun KJ, Muiruri V, Rucina SM, Marchant R. Late Holocene wetland transgression and 500 years of vegetation and fire variability in the semi-arid Amboseli landscape, southern Kenya. Ambio 2018; 47:682-696. [PMID: 29397542 PMCID: PMC6131128 DOI: 10.1007/s13280-018-1014-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/01/2017] [Accepted: 01/05/2018] [Indexed: 06/07/2023]
Abstract
The semi-arid Amboseli landscape, southern Kenya, is characterised by intermittent groundwater-fed wetlands that form sedimentary geoarchives recording past ecosystem changes. We present a 5000-year environmental history of a radiocarbon dated sediment core from Esambu Swamp adjacent to Amboseli National Park. Although radiocarbon dates suggest an unconformity or sedimentary gap that spans between 3800 and 500 cal year BP, the record provides a unique insight into the long-term ecosystem history and wetland processes, particularly the past 500 years. Climatic shifts, fire activity and recent anthropogenic activity drive changes in ecosystem composition. Prior to 3800 cal year BP the pollen data suggest semi-arid savanna ecosystem persisted near the wetland. The wetland transgressed at some time between 3800 and 500 cal year BP and it is difficult to constrain this timing further, and palustrine peaty sediments have accumulated since 400 cal year BP. Increased abundance of Afromontane forest taxa from adjacent highlands of Kilimanjaro and the Chyulu Hills and local arboreal taxa reflect changes in regional moisture budgets. Particularly transformative changes occurred in the last five centuries, associated with increased local biomass burning coeval with the arrival of Maa-speaking pastoralists and intensification of the ivory trade. Cereal crops occurred consistently from around 300 cal year BP, indicative of further anthropogenic activity. The study provides unique insight in Amboseli ecosystem history and the link between ecosystem drivers of change. Such long-term perspectives are crucial for future climate change and associated livelihood impacts, so that suitable responses to ensure sustainable management practices can be developed in an important conservation landscape.
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Affiliation(s)
- Esther N. Githumbi
- York Institute for Tropical Ecosystems, Environment Department, University of York, Heslington, York, YO10 5NG UK
| | - Colin J. Courtney Mustaphi
- York Institute for Tropical Ecosystems, Environment Department, University of York, Heslington, York, YO10 5NG UK
- Department of Archaeology and Ancient History, Uppsala Universitet, P.O. Box 256, 751 05 Uppsala, Sweden
| | - Kevin J. Yun
- Department of Biosciences, School of Biological and Biomedical Sciences, Durham University, Stockton Road, Durham, DH1 3LE UK
| | - Veronica Muiruri
- Department of Earth Sciences, Palynology and Palaeobotany Section, National Museums of Kenya, P.O BOX 45166 00100, Nairobi, Kenya
- Hong Kong Baptist University, Hong Kong, China
| | - Stephen M. Rucina
- Department of Earth Sciences, Palynology and Palaeobotany Section, National Museums of Kenya, P.O BOX 45166 00100, Nairobi, Kenya
| | - Rob Marchant
- York Institute for Tropical Ecosystems, Environment Department, University of York, Heslington, York, YO10 5NG UK
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21
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Nóbrega RLB, Guzha AC, Lamparter G, Amorim RSS, Couto EG, Hughes HJ, Jungkunst HF, Gerold G. Impacts of land-use and land-cover change on stream hydrochemistry in the Cerrado and Amazon biomes. Sci Total Environ 2018; 635:259-274. [PMID: 29665544 DOI: 10.1016/j.scitotenv.2018.03.356] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 03/29/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Studies on the impacts of land-use and land-cover change on stream hydrochemistry in active deforestation zones of the Amazon agricultural frontier are limited and have often used low-temporal-resolution datasets. Moreover, these impacts are not concurrently assessed in well-established agricultural areas and new deforestations hotspots. We aimed to identify these impacts using an experimental setup to collect high-temporal-resolution hydrological and hydrochemical data in two pairs of low-order streams in catchments under contrasting land use and land cover (native vegetation vs. pasture) in the Amazon and Cerrado biomes. Our results indicate that the conversion of natural landscapes to pastures increases carbon and nutrient fluxes via streamflow in both biomes. These changes were the greatest in total inorganic carbon in the Amazon and in potassium in the Cerrado, representing a 5.0- and 5.5-fold increase in the fluxes of each biome, respectively. We found that stormflow, which is often neglected in studies on stream hydrochemistry in the tropics, plays a substantial role in the carbon and nutrient fluxes, especially in the Amazon biome, as its contributions to hydrochemical fluxes are mostly greater than the volumetric contribution to the total streamflow. These findings demonstrate that assessments of the impacts of deforestation in the Amazon and Cerrado biomes should also take into account rapid hydrological pathways; however, this can only be achieved through collection of high-temporal-resolution data.
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Affiliation(s)
- Rodolfo L B Nóbrega
- University of Goettingen, Faculty of Geoscience and Geography, Goettingen, Germany.
| | - Alphonce C Guzha
- U.S.D.A. Forest Service, International Programs, c/o CIFOR, World Agroforestry Center, Nairobi, Kenya
| | - Gabriele Lamparter
- University of Goettingen, Faculty of Geoscience and Geography, Goettingen, Germany
| | - Ricardo S S Amorim
- Federal University of Mato Grosso, Department of Soil and Agricultural Engineering, Cuiabá, Brazil
| | - Eduardo G Couto
- Federal University of Mato Grosso, Department of Soil and Agricultural Engineering, Cuiabá, Brazil
| | - Harold J Hughes
- University of Goettingen, Faculty of Geoscience and Geography, Goettingen, Germany
| | - Hermann F Jungkunst
- University of Koblenz-Landau, Institute for Environmental Sciences, Geoecology & Physical Geography, Landau, Germany
| | - Gerhard Gerold
- University of Goettingen, Faculty of Geoscience and Geography, Goettingen, Germany
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22
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Schwieder M, Leitão PJ, Pinto JRR, Teixeira AMC, Pedroni F, Sanchez M, Bustamante MM, Hostert P. Landsat phenological metrics and their relation to aboveground carbon in the Brazilian Savanna. Carbon Balance Manag 2018; 13:7. [PMID: 29766371 PMCID: PMC5953907 DOI: 10.1186/s13021-018-0097-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 05/05/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND The quantification and spatially explicit mapping of carbon stocks in terrestrial ecosystems is important to better understand the global carbon cycle and to monitor and report change processes, especially in the context of international policy mechanisms such as REDD+ or the implementation of Nationally Determined Contributions (NDCs) and the UN Sustainable Development Goals (SDGs). Especially in heterogeneous ecosystems, such as Savannas, accurate carbon quantifications are still lacking, where highly variable vegetation densities occur and a strong seasonality hinders consistent data acquisition. In order to account for these challenges we analyzed the potential of land surface phenological metrics derived from gap-filled 8-day Landsat time series for carbon mapping. We selected three areas located in different subregions in the central Brazil region, which is a prominent example of a Savanna with significant carbon stocks that has been undergoing extensive land cover conversions. Here phenological metrics from the season 2014/2015 were combined with aboveground carbon field samples of cerrado sensu stricto vegetation using Random Forest regression models to map the regional carbon distribution and to analyze the relation between phenological metrics and aboveground carbon. RESULTS The gap filling approach enabled to accurately approximate the original Landsat ETM+ and OLI EVI values and the subsequent derivation of annual phenological metrics. Random Forest model performances varied between the three study areas with RMSE values of 1.64 t/ha (mean relative RMSE 30%), 2.35 t/ha (46%) and 2.18 t/ha (45%). Comparable relationships between remote sensing based land surface phenological metrics and aboveground carbon were observed in all study areas. Aboveground carbon distributions could be mapped and revealed comprehensible spatial patterns. CONCLUSION Phenological metrics were derived from 8-day Landsat time series with a spatial resolution that is sufficient to capture gradual changes in carbon stocks of heterogeneous Savanna ecosystems. These metrics revealed the relationship between aboveground carbon and the phenology of the observed vegetation. Our results suggest that metrics relating to the seasonal minimum and maximum values were the most influential variables and bear potential to improve spatially explicit mapping approaches in heterogeneous ecosystems, where both spatial and temporal resolutions are critical.
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Affiliation(s)
- M Schwieder
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany.
| | - P J Leitão
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
- Department Landscape Ecology and Environmental System Analysis, Institute of Geoecology, Technische Universität Braunschweig, Langer Kamp 19c, 38106, Braunschweig, Germany
| | - J R R Pinto
- Departamento de Engenharia Florestal, Universidade de Brasília, Brasília, DF, 70919-970, Brazil
| | - A M C Teixeira
- Graduate Program in Botany, University of Brasília, Brasília, DF, 70919-970, Brazil
| | - F Pedroni
- Instituto de Ciências Biológicas e da Saúde, Universidade Federal de Mato Grosso, Pontal do Araguaia, MT, 78698-000, Brazil
| | - M Sanchez
- Instituto de Ciências Biológicas e da Saúde, Universidade Federal de Mato Grosso, Pontal do Araguaia, MT, 78698-000, Brazil
| | - M M Bustamante
- Departamento de Ecologia, Universidade de Brasília, Brasília, DF, 70919-970, Brazil
| | - P Hostert
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
- Integrative Research Institute on Transformations of Human-Environment Systems-IRI THESys, Humboldt-Universitätzu Berlin, Unter den Linden 6, 10099, Berlin, Germany
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23
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Setterfield SA, Andersen AN. Seed supply limits seedling recruitment of Eucalyptus miniata: interactions between seed predation by ants and fire in the Australian seasonal tropics. Oecologia 2018; 186:965-972. [PMID: 29357030 DOI: 10.1007/s00442-018-4061-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 01/05/2018] [Indexed: 11/30/2022]
Abstract
Seed predation can cause substantial seed losses and influence plant population dynamics, but the impact depends on the extent to which populations are limited by seed availability or favorable microsites for recruitment. Harvester ants are the dominant post-dispersal seed predators in Australia's tropical savannas, and their abundance and foraging efficiency, as well as the availability of seed and microsites, are affected by fire history. We undertook a predator-exclusion experiment to examine the interactive effects of fire history (no fire compared with annual burning over 5 years) and seed predation by ants on seedling establishment of the dominant savanna tree, Eucalyptus miniata, in northern Australia. Despite its large seed size, the rate of removal (~ 20-60%) was similar or higher than typically reported for eucalypts, although it was lower than that recorded for the smaller seeds of the co-occurring E. tetrodonta. Seed predation rates were twice as high in annually burnt compared to unburnt sites, but there was no significant difference in the proportion of seedlings that emerged from the initial seed available. Seedling emergence in both regimes was low, representing < 7% of seed available after harvesting. About one-third of emergent seedlings were still alive during the middle of the following dry season. Our results indicate that seedling recruitment in E. miniata is limited by both seed supply and microsite availability. However, seed predation by ants reduces the likelihood of seedling establishment from low to virtually zero, which suggests that it plays a potentially important role in the population dynamics of savanna eucalypts.
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Affiliation(s)
- Samantha Ann Setterfield
- School of Biological Sciences, University of Western Australia, Crawley, WA, 6009, Australia. .,Charles Darwin University, Darwin, NT, 0909, Australia.
| | - Alan Neil Andersen
- Charles Darwin University, Darwin, NT, 0909, Australia.,CSIRO Tropical Ecosystem Research Centre, PMB 44, Winnellie, Darwin, NT, 0822, Australia
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24
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Batista EKL, Russell-Smith J, França H, Figueira JEC. An evaluation of contemporary savanna fire regimes in the Canastra National Park, Brazil: Outcomes of fire suppression policies. J Environ Manage 2018; 205:40-49. [PMID: 28964973 DOI: 10.1016/j.jenvman.2017.09.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 06/07/2023]
Abstract
Fire has shaped plant evolution and biogeochemical cycles for millions of years in savanna ecosystems, but changes in natural fire regimes promoted by human land use threaten contemporary conservation efforts. In protected areas in the Brazilian savannas (Cerrado), the predominant management policy is fire suppression, reflecting a cultural heritage which considers that fire always has a negative impact on biodiversity. Here we compare resultant fire-regimes in Canastra National Park (CNP), southeast Brazil, associated with areas under and without fire suppression management, based on a 16-year Landsat imagery record. In open grasslands of the Canastra plateau (CP), firefighting is undertaken under government-sanctioned regulation, whereas in the Babilonia sector, non-sanctioned fire management is undertaken by small farmers to promote cattle grazing and cropping. Fire regimes in the Canastra sector are characterized by few, very large, late dry season wildfires recurring at intervals of two years. Fire regimes in lowlands of the Babilonia sector are characterized by many small-scale, starting at the beginning of the dry season (EDS). In Babilonia uplands fire regimes are characterized by higher frequencies of large fires. The study illustrates major challenges for managing fire-prone areas in conflict-of-interest regions. We suggest that management planning in CNP needs to effectively address: i) managing conflicts between CNP managers and local communities; and ii) fire management practices in order to achieve more ecologically sustainable fire regimes. The study has broader implications for conservation management in fire-prone savannas in South America generally.
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Affiliation(s)
| | - Jeremy Russell-Smith
- Darwin Centre for Bushfire Research, Charles Darwin University, Darwin, Australia.
| | - Helena França
- Engineering Center, Modeling and Applied Social Sciences, Federal University of ABC, Brazil.
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25
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Gosling WD, Julier ACM, Adu-Bredu S, Djagbletey GD, Fraser WT, Jardine PE, Lomax BH, Malhi Y, Manu EA, Mayle FE, Moore S. Pollen-vegetation richness and diversity relationships in the tropics. Veg Hist Archaeobot 2017; 27:411-418. [PMID: 31983811 PMCID: PMC6953967 DOI: 10.1007/s00334-017-0642-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 09/25/2017] [Indexed: 06/10/2023]
Abstract
Tracking changes in biodiversity through time requires an understanding of the relationship between modern diversity and how this diversity is preserved in the fossil record. Fossil pollen is one way in which past vegetation diversity can be reconstructed. However, there is limited understanding of modern pollen-vegetation diversity relationships from biodiverse tropical ecosystems. Here, pollen (palynological) richness and diversity (Hill N 1) are compared with vegetation richness and diversity from forest and savannah ecosystems in the New World and Old World tropics (Neotropics and Palaeotropics). Modern pollen data were obtained from artificial pollen traps deployed in 1-ha vegetation study plots from which vegetation inventories had been completed in Bolivia and Ghana. Pollen counts were obtained from 15 to 22 traps per plot, and aggregated pollen sums for each plot were > 2,500. The palynological richness/diversity values from the Neotropics were moist evergreen forest = 86/6.8, semi-deciduous dry forest = 111/21.9, wooded savannah = 138/31.5, and from the Palaeotropics wet evergreen forest = 144/28.3, semi-deciduous moist forest = 104/4.4, forest-savannah transition = 121/14.1; the corresponding vegetation richness/diversity was 100/36.7, 80/38.7 and 71/39.4 (Neotropics), and 101/54.8, 87/45.5 and 71/34.5 (Palaeotropics). No consistent relationship was found between palynological richness/diversity, and plot vegetation richness/diversity, due to the differential influence of other factors such as landscape diversity, pollination strategy, and pollen source area. Palynological richness exceeded vegetation richness, while pollen diversity was lower than vegetation diversity. The relatively high global diversity of tropical vegetation was found to be reflected in the pollen rain.
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Affiliation(s)
- William D. Gosling
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - Adele C. M. Julier
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | | | | | - Wesley T. Fraser
- Geography, Department of Social Sciences, Oxford Brookes University, Oxford, UK
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - Phillip E. Jardine
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
- Institute of Earth and Environmental Sciences, Universität Potsdam, Potsdam, Germany
| | - Barry H. Lomax
- Agricultural and Environmental Sciences, The University of Nottingham, Nottingham, UK
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | | | - Francis E. Mayle
- Department of Geography and Environmental Science, University of Reading, Reading, UK
| | - Sam Moore
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
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26
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Yadav IC, Linthoingambi Devi N, Li J, Syed JH, Zhang G, Watanabe H. Biomass burning in Indo-China peninsula and its impacts on regional air quality and global climate change-a review. Environ Pollut 2017; 227:414-427. [PMID: 28486185 DOI: 10.1016/j.envpol.2017.04.085] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/27/2017] [Accepted: 04/29/2017] [Indexed: 05/22/2023]
Abstract
Although, many biomass burning (BB) emissions products (particulate matter and trace gases) are believed to be trans-boundary pollutants that originates from India and China (the two most populous countries in Asia), the information about BB emission and related contents is limited for Indo-China Peninsula (ICP) region. This motivated us to review this region pertaining to BB emission. The main objective of the review is to document the current status of BB emission in ICP region. In order to highlight the impact of BB on regional air quality and global climate change, the role of BB emission in ICP region is also discussed. Based on the available literature and modeling simulations studies, it is evidenced that ICP is one of the hotspot regional source for aerosols in terms of BB emissions. In addition, regional emissions through BB have significant implications for regional air quality especially in the neighboring countries such as China, Taiwan and India. Our assessment highlight that there is still a general lack of reliable data and research studies addressing BB related issues in context of environmental and human health. There is therefore a critical need to improve the current knowledge base, which should build upon the research experience and further research into these issues is considered vital to help inform future policies/control strategies.
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Affiliation(s)
- Ishwar Chandra Yadav
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Department of International Environmental and Agricultural Science (IEAS), Tokyo University of Agriculture and Technology (TUAT) 3-5-8, Saiwaicho, Fuchu, Tokyo 1838509, Japan.
| | | | - Jun Li
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Jabir Hussain Syed
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Hirozumi Watanabe
- Department of International Environmental and Agricultural Science (IEAS), Tokyo University of Agriculture and Technology (TUAT) 3-5-8, Saiwaicho, Fuchu, Tokyo 1838509, Japan
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27
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Pickens BA, Marcus JF, Carpenter JP, Anderson S, Taillie PJ, Collazo JA. The effect of urban growth on landscape-scale restoration for a fire-dependent songbird. J Environ Manage 2017; 191:105-115. [PMID: 28088724 DOI: 10.1016/j.jenvman.2017.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 12/27/2016] [Accepted: 01/03/2017] [Indexed: 06/06/2023]
Abstract
A landscape-scale perspective on restoration ecology has been advocated, but few studies have informed restoration with landscape metrics or addressed broad-scale threats. Threats such as urban growth may affect restoration effectiveness in a landscape context. Here, we studied longleaf pine savanna in the rapidly urbanizing southeastern United States where a habitat-specialist bird, Bachman's sparrow (Peucaea aestivalis), is closely associated with savanna vegetation structure and frequent fire. Our objectives were to construct a species distribution model for Bachman's sparrow, determine the relationship between fire and urbanization, quantify the urban growth effect (2010-2090), identify potential restoration areas, and determine the interaction between restoration potential and urban growth by 2050. Number of patches, patch size, and isolation metrics were used to evaluate scenarios. The species distribution model was 88% accurate and emphasized multiscale canopy cover characteristics, fire, and percent habitat. Fires were less common <600 m from urban areas, and this fire suppression effect exacerbated urban growth effects. For restoration scenarios, canopy cover reduction by 30% resulted in nearly double the amount of habitat compared to the prescribed fire scenario; canopy cover reduction resulted in larger patch sizes and less patch isolation compared to current conditions. The effect of urban growth on restoration scenarios was unequal. Seventy-four percent of restoration areas from the prescribed fire scenario overlapped with projected urban growth, whereas the canopy cover reduction scenario only overlapped by 9%. We emphasize the benefits of simultaneously considering the effects of urban growth and landscape-scale restoration potential to promote a landscape with greater patch sizes and less isolation.
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Affiliation(s)
- Bradley A Pickens
- North Carolina Cooperative Fish and Wildlife Research Unit, Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA.
| | - Jeffrey F Marcus
- The Nature Conservancy, 140 SW Broad St, Southern Pines, NC 28387, USA
| | - John P Carpenter
- North Carolina Wildlife Resources Commission, 1751 Varsity Dr, Raleigh, NC 27606, USA
| | - Scott Anderson
- North Carolina Wildlife Resources Commission, 1751 Varsity Dr, Raleigh, NC 27606, USA
| | - Paul J Taillie
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
| | - Jaime A Collazo
- U.S. Geological Survey, North Carolina Cooperative Fish and Wildlife Research Unit, Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA
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28
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Hernández-Hernández RM, Roldán A, Caravaca F, Rodriguez-Caballero G, Torres MP, Maestre FT, Alguacil MM. Arbuscular mycorrhizal fungal assemblages in biological crusts from a Neotropical savanna are not related to the dominant perennial Trachypogon. Sci Total Environ 2017; 575:1203-1210. [PMID: 27697347 DOI: 10.1016/j.scitotenv.2016.09.190] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 06/06/2023]
Abstract
Knowledge of the arbuscular mycorrhizal fungal assemblages in the Trachypogon savanna ecosystems is very important to a better understanding of the ecological processes mediated by this soil microbial group that affects multiple ecosystem functions. Considering the hypothesis that the biocrusts can be linked to vegetation through the arbuscular fungi mycelial network, the objectives proposed in this study were to determine (i) whether there are arbuscular mycorrhizal fungi (AMF) in the biocrusts (ii) whether arbuscular mycorrhizal fungal assemblages are linked to the Trachypogon patches, and (iii) whether the composition of the assemblages is related to soil properties affected by microbiological activity. The community structure of the AMF was investigated in three habitats: rhizospheric soil and roots of Trachypogon vestitus, biological soil crusts, and bare soil. The canonical correspondence analysis showed that two soil properties related to enzymatic activity (protease and β-glucosidase) significantly affected the community composition of the AMF. The biocrusts in the Venezuelan savanna are colonized by an AM fungal community linked to that of the bare soil and significantly different from that hosted by the roots of the surrounding T. vestitus, suggesting that assemblages of AMF in biocrusts might be related more closely to those of annual plant species appearing in favorable conditions.
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Affiliation(s)
- R M Hernández-Hernández
- Universidad Simón Rodríguez (USR), Instituto de Estudios Científicos y Tecnológicos IDECYT, Av. Mara Altos del Cují, San Antonio de los Altos, estado Miranda, Apdo 47925, Venezuela
| | - A Roldán
- CSIC-Centro de Edafología y Biología Aplicada del Segura, Department of Soil and Water Conservation, P.O. Box 164, Campus de Espinardo, 30100 Murcia, Spain
| | - F Caravaca
- CSIC-Centro de Edafología y Biología Aplicada del Segura, Department of Soil and Water Conservation, P.O. Box 164, Campus de Espinardo, 30100 Murcia, Spain
| | - G Rodriguez-Caballero
- CSIC-Centro de Edafología y Biología Aplicada del Segura, Department of Soil and Water Conservation, P.O. Box 164, Campus de Espinardo, 30100 Murcia, Spain
| | - M P Torres
- Departamento de Biología Aplicada, Área de Botánica, Universidad Miguel Hernández, Avda. De la Universidad s/n., 03202 Elche, Alicante, Spain
| | - F 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 28933, Spain
| | - M M Alguacil
- CSIC-Centro de Edafología y Biología Aplicada del Segura, Department of Soil and Water Conservation, P.O. Box 164, Campus de Espinardo, 30100 Murcia, Spain.
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Neoh KB, Bong LJ, Muhammad A, Itoh M, Kozan O, Takematsu Y, Yoshimura T. The Impact of Tropical Peat Fire on Termite Assemblage in Sumatra, Indonesia: Reduced Complexity of Community Structure and Survival Strategies. Environ Entomol 2016; 45:1170-1177. [PMID: 27550162 DOI: 10.1093/ee/nvw116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/04/2016] [Indexed: 06/06/2023]
Abstract
Tropical peat swamp forests in Southeast Asia account for approximately 72% of global peatland. However, extensive forest exploitation following peat drainage for agricultural expansion has been leading to catastrophic peat fires. In this study, we compared the termite assemblage in burnt and unburnt peats in Sumatra, Indonesia. We also identified which taxonomic group is particularly resistant to fire disturbance and the traits that correlate with its persistence in fire-impacted peatlands. Overall, the termite species richness in fire-impacted peats was up to 40% lower than that of the total species found in peat swamp forests. Although the estimated species richness values in fire-impacted peats and peat swamp forests were not significantly different, fire changed termite community structure significantly. Only termites of the family Rhinotermitidae survived in the fire event, whereas members of the Termitidae that were reportedly resilient to fire and open habitats elsewhere disappeared during the fire events. The rhinotermitids found in the burnt sites were exclusively wood nesters. This suggests that the desiccation tolerance of termites in open habitat is not the simple underlying survival strategy, but tree branches and barks might have provided a refuge from heat during fire. The result also suggests that the high similarity in species composition in recently burnt peats and long burnt peats implies low species turnover. Thus, regardless of how much time had passed since the fire-impacted peats were abandoned or cultivated, the increase in habitat complexity did not favor colonization by the forest-dependent group.
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Affiliation(s)
- Kok-Boon Neoh
- Department of Entomology, National Chung Hsing University, 250 Guoguang Rd, Taichung 40227, Taiwan
| | - Lee-Jin Bong
- Laboratory of Innovative Humano-Habitability, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan (; )
| | - Ahmad Muhammad
- Department of Biology Faculty of Mathematics & Natural Sciences, Riau University, Jl. HR Soebrantas Km 12.5, Pekanbaru, 28293, Indonesia
| | - Masayuki Itoh
- Center for Southeast Asian Studies, 46 Shimoadachi-cho, Kyoto, 606-8501, Japan, Kyoto University, Yoshida Sakyo-ku (; )
| | - Osamu Kozan
- Center for Southeast Asian Studies, 46 Shimoadachi-cho, Kyoto, 606-8501, Japan, Kyoto University, Yoshida Sakyo-ku (; )
| | - Yoko Takematsu
- Faculty of Agriculture, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, 753-8515, Japan
| | - Tsuyoshi Yoshimura
- Laboratory of Innovative Humano-Habitability, Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan (; )
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30
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Aranda R, Graciolli G. Environmental Heterogeneity in Parasitoid-Host Interaction for Mutillidae (Hymenoptera: Apocrita). Environ Entomol 2016; 45:1146-1153. [PMID: 27555643 DOI: 10.1093/ee/nvw098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/14/2016] [Indexed: 06/06/2023]
Abstract
Environmental heterogeneity is a major factor influencing the spatial distribution of organisms. Due to intimate relationships with their hosts, parasitic insects are inclined to be even more sensitive to variations. This study aimed to verify the relationship between spatial distribution of Mutillidae, potential hosts, and the effect of heterogeneity in the distribution of both, testing the hypotheses: i) the spatial distribution of mutillids depends on the distribution of hosts and ii) variation in environmental heterogeneity affects the distribution of both. Sampling was conducted in four fragments of the Cerrado. We collected Hymenopteran specimens from 25 plots of one hectare using 18 Malaise traps throughout one year, totalizing 32,400 trap-hours. Female Mutillidae were hand collected at all sampling points, for a total of 450 man-hours. At each hectare plot, we obtained the environmental variables from nine plots of 25 m2 A total of 1,089 individuals were collected (Apidae: 311; Crabronidae: 165; Shpecidae: 84; Vespidae: 229) belonging to 127 species of potential hosts (bees and wasps) and 300 individuals (42 species) of Mutillidae. Leaf-litter depths showed significant relation in host-parasitoid distribution. The spatiotemporal distribution followed the predator-prey model for Mutillidae, and environmental heterogeneity was a factor that determined the structure of the host-parasitoid community. The results suggest an intense relationship between the Mutillidae and Crabronidae, as well as Sphecidae and two Apidae subfamilies (Halictinae and Colletinae). These families and subfamilies present behavior in which they build nests in aggregations even each female being solitary. Crabronidae is considered the best potential host for Mutillidae.
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Affiliation(s)
- R Aranda
- Programa de Pós-graduação em Ecologia e Conservação, Universidade Federal de Mato Grosso do Sul, Centro de Ciências Biológicas e da Saúde - Cidade Universitária s/n - CEP: 79070900, Caixa Postal 549, Campo Grande, MS, Brasil
| | - G Graciolli
- Universidade Federal de Mato Grosso do Sul, Centro de Ciências Biológicas e da Saúde - Cidade Universitária s/n - CEP: 79070900, Caixa Postal 549, Campo Grande, MS, Brasil
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Yatat V, Couteron P, Tewa JJ, Bowong S, Dumont Y. An impulsive modelling framework of fire occurrence in a size-structured model of tree-grass interactions for savanna ecosystems. J Math Biol 2017; 74:1425-82. [PMID: 27659304 DOI: 10.1007/s00285-016-1060-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 06/21/2016] [Indexed: 10/21/2022]
Abstract
Fires and mean annual rainfall are major factors that regulate woody and grassy biomasses in savanna ecosystems. Within the savanna biome, conditions of long-lasting coexistence of trees and grasses have been often studied using continuous-time modelling of tree-grass competition. In these studies, fire is a time-continuous forcing while the relationship between woody plant size and fire-sensitivity is not systematically considered. In this paper, we propose a new mathematical framework to model tree-grass interactions that takes into account both the impulsive nature of fire occurrence and size-dependent fire sensitivity (via two classes of woody plants). We carry out a qualitative analysis that highlights ecological thresholds and bifurcation parameters that shape the dynamics of the savanna-like systems within the main ecological zones. Through a qualitative analysis, we show that the impulsive modelling of fire occurrences leads to more diverse behaviors including cases of grassland, savanna and forest tristability and a more realistic array of solutions than the analogous time-continuous fire models. Numerical simulations are carried out with respect to the three main ecological contexts (moist, mesic, semi-arid) to illustrate the theoretical results and to support a discussion about the bifurcation parameters and the advantages of the model.
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Abstract
C4 photosynthesis is absent from the arborescent life form, with the exception of seven Hawaiian Euphorbia species and a few desert shrubs that become arborescent with age. As a consequence, wherever C3 trees can establish, their height advantage enables them to outcompete low stature C4 vegetation. Had C4 photosynthesis been able to evolve in an arborescent life form, forest cover (by C4 trees) could have been much more extensive than today, with significant consequences for the biosphere. Here, we address why there are so few C4 trees. Physiological explanations associated with low light performance of C4 photosynthesis are not supported, because C4 shade-tolerant species exhibit similar performance as shade-tolerant C3 species in terms of quantum yield, steady-state photosynthetic and use of sunflecks. Hence, hypothetical C4 trees could occur in the regeneration niche of forests. Constraints associated with the evolutionary history of the C4 lineages are more plausible. Most C4 species are grasses and sedges, which lack meristems needed for arborescence, while most C4 eudicots are highly specialized for harsh (arid, saline, hot) or disturbed habitats where arborescence may be maladapted. Most C4 eudicot clades are also young, and have not had sufficient time to radiate beyond the extreme environments where C4 evolution is favored. In the case of the Hawaiian Euphorbia species, they belong to one of the oldest and most diverse C4 lineages, which primed this group to evolve arborescence in a low-competition environment that appeared on the remote Hawaiian Islands.
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Affiliation(s)
- Rowan F Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON M5S3B2, Canada.
| | - Stefanie Sultmanis
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON M5S3B2, Canada
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Zhu L, Southworth J, Meng J. Comparison of the driving forces of spring phenology among savanna landscapes by including combined spatial and temporal heterogeneity. Int J Biometeorol 2015; 59:1373-1384. [PMID: 25542243 DOI: 10.1007/s00484-014-0947-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 12/13/2014] [Accepted: 12/14/2014] [Indexed: 06/04/2023]
Abstract
Understanding spatial and temporal dynamics of land surface phenology (LSP) and its driving forces are critical for providing information relevant to short- and long-term decision making, particularly as it relates to climate response planning. With the third generation Global Inventory Monitoring and Modeling System (GIMMS3g) Normalized Difference Vegetation Index (NDVI) data and environmental data from multiple sources, we investigated the spatio-temporal changes in the start of the growing season (SOS) in southern African savannas from 1982 through 2010 and determined its linkage to environmental factors using spatial panel data models. Overall, the SOS occurs earlier in the north compared to the south. This relates in part to the differences in ecosystems, with northern areas representing high rainfall and dense tree cover (mainly tree savannas), whereas the south has lower rainfall and sparse tree cover (mainly bush and grass savannas). From 1982 to 2010, an advanced trend was observed predominantly in the tree savanna areas of the north, whereas a delayed trend was chiefly found in the floodplain of the north and bush/grass savannas of the south. Different environmental drivers were detected within tree- and grass-dominated savannas, with a critical division being represented by the 800 mm isohyet. Our results supported the importance of water as a driver in this water-limited system, specifically preseason soil moisture, in determining the SOS in these water-limited, grass-dominated savannas. In addition, the research pointed to other, often overlooked, effects of preseason maximum and minimum temperatures on the SOS across the entire region. Higher preseason maximum temperatures led to an advance of the SOS, whereas the opposite effects of preseason minimum temperature were observed. With the rapid increase in global change research, this work will prove helpful for managing savanna landscapes and key to predicting how projected climate changes will affect regional vegetation phenology and productivity.
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Affiliation(s)
- Likai Zhu
- Department of Geography, University of Florida, 3141 Turlington Hall, P.O. Box 117315, Gainesville, FL, 32611, USA.
| | - Jane Southworth
- Department of Geography, University of Florida, 3141 Turlington Hall, P.O. Box 117315, Gainesville, FL, 32611, USA.
| | - Jijun Meng
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
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Hanberry BB, Dey DC, He HS. The history of widespread decrease in oak dominance exemplified in a grassland-forest landscape. Sci Total Environ 2014; 476-477:591-600. [PMID: 24496032 DOI: 10.1016/j.scitotenv.2014.01.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/14/2014] [Accepted: 01/15/2014] [Indexed: 06/03/2023]
Abstract
Regionally-distinctive open oak forest ecosystems have been replaced either by intensive agriculture and grazing fields or by denser forests throughout eastern North America and Europe. To quantify changes in tree communities and density in the Missouri Plains, a grassland-forest landscape, we used historical surveys from 1815 to 1864 and current surveys from 2004 to 2008. To estimate density for historical communities, we used the Morisita plotless density estimator and applied corrections for surveyor bias. To estimate density for current forests, we used Random Forests, an ensemble regression tree method, to predict densities from known values at plots using terrain and soil predictors. Oak species decreased from 62% of historical composition to 30% of current composition and black and white oaks historically were dominant species across 93% of the landscape and currently were dominant species across 42% of the landscape. Current forest density was approximately two times greater than historical densities, demonstrating loss of savanna and woodlands and transition to dense forest structure. Average tree diameters were smaller than in the past, but mean basal area and stocking remained similar over time because of the increase in density in current forests. Nevertheless, there were spatial differences; basal area and stocking decreased along rivers and increased away from rivers. Oak species are being replaced by other species in the Missouri Plains, similar to replacement throughout the range of Quercus. Long-term commitment to combinations of prescribed burning and silvicultural prescriptions in more xeric sites may be necessary for oak recruitment. Restoration of open oak ecosystems is a time-sensitive issue because restoration will become increasingly costly as oaks are lost from the overstory and the surrounding matrix becomes dominated by non-oak species.
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Affiliation(s)
- Brice B Hanberry
- University of Missouri, 203 Natural Resources Building, Columbia, MO 65211, USA.
| | - Daniel C Dey
- USDA Forest Service, Northern Research Station, University of Missouri, 202 Natural Resources Building, Columbia, MO 65211, USA
| | - Hong S He
- University of Missouri, 203 Natural Resources Building, Columbia, MO 65211, USA
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Boudouris J, Queenborough SA. Diversity and distribution of extra-floral nectaries in the cerrado savanna vegetation of Brazil. PeerJ 2013; 1:e219. [PMID: 24349899 PMCID: PMC3845873 DOI: 10.7717/peerj.219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 11/11/2013] [Indexed: 11/20/2022] Open
Abstract
Aim. Throughout evolutionary history, plants and animals have evolved alongside one another. This is especially apparent when considering mutualistic relationships such as between plants with extra-floral nectaries (EFNs, glands on leaves or stems that secrete nectar) and the ants that visit them. Ants are attracted by the nectar and then protect the plant against destructive herbivores. The distribution of these plants is of particular interest, because it can provide insights into the evolutionary history of this unique trait and the plants that possess it. In this study, we investigated factors driving the distribution of woody plants with EFNs in the cerrado vegetation of Brazil. Location. Brazil Methods. We used a database detailing the incidence of 849 plant species at 367 cerrado sites throughout Brazil. We determined which species possessed EFNs and mapped their distributions. We tested for correlations between the proportion of EFN species at each site and (i) three environmental variables (mean annual temperature, mean annual precipitation, and the precipitation in the driest quarter of the year), (ii) a broad soil classification, and (iii) the total species diversity of each site. Results. We found a wide range in the proportion of EFN species at any one site (0–57%). However, whilst low diversity sites had wide variation in the number of EFN species, high diversity sites all had few EFN species. The proportion of EFN species was positively correlated with absolute latitude and negatively correlated with longitude. When accounting for total species diversity, the proportion of EFN species per site was negatively correlated with precipitation in the driest quarter of the year and positively correlated with temperature range. Main Conclusions. These results suggest either that herbivore pressure may be lower in drier sites, or that ants are not as dominant in these locations, or that plant lineages at these sites were unable to evolve EFNs.
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Affiliation(s)
- John Boudouris
- Department of Evolution, Ecology & Organismal Biology, The Ohio State University , Columbus, OH , USA
| | - Simon A Queenborough
- Department of Evolution, Ecology & Organismal Biology, The Ohio State University , Columbus, OH , USA
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Bresolin JD, Bustamante MMC, Krüger RH, Silva MRSS, Perez KS. Structure and composition of bacterial and fungal community in soil under soybean monoculture in the Brazilian Cerrado. Braz J Microbiol 2010; 41:391-403. [PMID: 24031510 PMCID: PMC3768672 DOI: 10.1590/s1517-838220100002000021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Revised: 04/14/2009] [Accepted: 01/20/2010] [Indexed: 11/21/2022] Open
Abstract
Soybean is the most important oilseed cultivated in the world and Brazil is the second major producer. Expansion of soybean cultivation has direct and indirect impacts on natural habitats of high conservation value, such as the Brazilian savannas (Cerrado). In addition to deforestation, land conversion includes the use of fertilizers and pesticides and can lead to changes in the soil microbial communities. This study evaluated the soil bacterial and fungal communities and the microbial biomass C in a native Cerrado and in a similar no-tillage soybean monoculture area using PCR-DGGE and sequencing of bands. Compared to the native area, microbial biomass C was lower in the soybean area and cluster analysis indicated that the structure of soil microbial communities differed. 16S and 18S rDNA dendrograms analysis did not show differences between row and inter-row samples, but microbial biomass C values were higher in inter-rows during soybean fructification and harvest. The study pointed to different responses and alterations in bacterial and fungal communities due to soil cover changes (fallow x growth period) and crop development. These changes might be related to differences in the pattern of root exudates affecting the soil microbial community. Among the bands chosen for sequencing there was a predominance of actinobacteria, γ-proteobacteria and ascomycetous divisions. Even under no-tillage management methods, the soil microbial community was affected due to changes in the soil cover and crop development, hence warning of the impacts caused by changes in land use.
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Affiliation(s)
- J D Bresolin
- Universidade de Brasília , Brasília, DF , Brasil
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Magnusson WE, Carmozina de Araújo M, Cintra R, Lima AP, Martinelli LA, Sanaiotti TM, Vasconcelos HL, Victoria RL. Contributions of C 3 and C 4 plants to higher trophic levels in an Amazonian savanna. Oecologia 1999; 119:91-6. [PMID: 28308164 DOI: 10.1007/PL00008821] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We studied the energy flow from C3 and C4 plants to higher trophic levels in a central Amazonian savanna by comparing the carbon stable-isotope ratios of potential food plants to the isotope ratios of species of different consumer groups. All C4 plants encountered in our study area were grasses and all C3 plants were bushes, shrubs or vines. Differences in δ13C ratios among bushes (x¯ = -30.8, SD = 1.2), vines (x¯ = -30.7, SD = 0.46) and trees (x¯ = -29.7, SD = 1.5) were small. However the mean δ13C ratio of dicotyledonous plants (x¯ = -30.4, SD = 1.3) was much more negative than that of the most common grasses (x¯ = -13.4, SD = 0.27). The insect primary consumers had δ13C ratios which ranged from a mean of -29.5 (SD = 0.47) for the grasshopper Tropidacris collaris to a mean of -14.7 (SD = 0.56) for a termite (Nasutitermes sp.), a range similar to that of the vegetation. However, the common insectivorous and omnivorous vertebrates had intermediate values for δ13C, indicating that carbon from different autotrophic sources mixes rapidly as it moves up the food chain. Despite this mixing, the frogs and lizards generally had higher values of δ13C (x¯ = -21.7, SD = 1.6; x¯ = -21.9, SD = 1.8, respectively) than the birds (x¯ = -24.8, SD = 1.8) and the only species of mammal resident in the savanna (x¯ = -25.4), indicating that they are generally more dependent on, or more able to utilise, food chains based on C4 grasses.
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Weltzin JF, McPherson GR. Spatial and temporal soil moisture resource partitioning by trees and grasses in a temperate savanna, Arizona, USA. Oecologia 1997; 112:156-64. [PMID: 28307565 DOI: 10.1007/s004420050295] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Stable isotope analysis was used to determine sources of water used by coexisting trees and grasses in a temperate savanna dominated by Quercus emoryi Torr. We predicted that (1) tree seedlings and bunchgrasses utilize shallow sources of soil water, (2) mature savanna trees use deeper sources of water, and (3) trees switch from shallow to deep water sources within 1 year of germination. We found that Q. emoryi trees, saplings, and seedlings (about 2 months, 1 year, and 2 years old), and the dominant bunchgrass [Trachypogon montufari (H.B.K.) Nees.] utilized seasonally available moisture from different depths within the soil profile depending on size/age relationships. Sapling and mature Q. emoryi acquired water from >50 cm deep, 2-month-old seedlings utilized water from <15 cm, and 1- and 2-year-old seedlings and grasses used water from between 20 cm and 35 cm. This suggests that very young seedlings are decoupled from grasses in this system, which may facilitate germination and early establishment of Q. emoryi within extant stands of native grasses. The potential for subsequent interaction between Q. emoryi and native grasses was evidenced by similar patterns of soil water use by 1- and 2-year-old seedlings and grasses. Q. emoryi seedlings did not switch from shallow to deep sources of soil water within 2 years of germination: water use by these seedlings apparently becomes independent of water use by grasses after 2 years of age. Finally, older trees (saplings, mature trees) use water from deeper soil layers than grasses, which may facilitate the stable coexistence of mature trees and grasses. Potential shifts in the seasonality of precipitation may alter interactions between woody plants and grasses within temperate savannas characterized by bimodal precipitation regimes: reductions in summer precipitation or soil moisture may be particularly detrimental to warm-season grasses and seedlings of Q. emoryi.
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Thomas Palo R, Gowda J, Högberg P. Species height and root symbiosis, two factors influencing antiherbivore defense of woody plants in East African savanna. Oecologia 1993; 93:322-6. [PMID: 28313430 DOI: 10.1007/BF00317873] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/1992] [Accepted: 09/30/1992] [Indexed: 10/26/2022]
Abstract
In East African savanna we found that leaves of mature tree species with symbiotic N2 fixation contained lower concentrations of polyphenols than leaves of species without this symbiosis. We suggest that the root symbiosis is costly to the plant in terms of photosynthate that otherwise could be used in chemical defense. Further, a negative relationship between concentration of polyphenols and the height of the species was found, independent of their ability to fix N2. These findings suggest that root symbioses and apparency to herbivory are important factors mediating the production of chemical defenses in plants.
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