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Cabal C, Maciel GA, Martinez-Garcia R. Plant antagonistic facilitation across environmental gradients: a soil-resource ecosystem engineering model. THE NEW PHYTOLOGIST 2024; 244:670-682. [PMID: 39165156 DOI: 10.1111/nph.20053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 07/24/2024] [Indexed: 08/22/2024]
Abstract
Theory questions the persistence of nonreciprocal interactions in which one plant has a positive net effect on a neighbor that, in return, has a negative net impact on its benefactor - a phenomenon known as antagonistic facilitation. We develop a spatially explicit consumer-resource model for belowground plant competition between ecosystem engineers, plants able to mine resources and make them available for any other plant in the community, and exploiters. We use the model to determine in what environmental conditions antagonistic facilitation via soil-resource engineering emerges as an optimal strategy. Antagonistic facilitation emerges in stressful environments where ecosystem engineers' self-benefits from mining resources outweigh the competition with opportunistic neighbors. Among all potential causes of stress considered in the model, the key environmental parameter driving changes in the interaction between plants is the proportion of the resource that becomes readily available for plant consumption in the absence of any mining activity. Our results align with theories of primary succession and the stress gradient hypothesis. However, we find that the total root biomass and its spatial allocation through the root system, often used to measure the sign of the interaction between plants, do not predict facilitation reliably.
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Affiliation(s)
- Ciro Cabal
- Global Change Research Institute, Rey Juan Carlos University (IICG-URJC), 28933, Móstoles, Spain
- High Meadows Environmental Institute, Princeton University (HMEI), 08544, Princeton, NJ, USA
- Department of Biology and Geology, Physics and Inorganic Chemistry, Rey Juan Carlos University, 28933, Móstoles, Spain
| | - Gabriel A Maciel
- ICTP-South American Institute for Fundamental Research - Instituto de Física Teórica da UNESP, 01140-070, São Paulo, Brazil
| | - Ricardo Martinez-Garcia
- Center for Advanced Systems Understanding, Helmholtz-Zentrum Dresden Rossendorf (CASUS-HZDR), 02826, Görlitz, Germany
- ICTP-South American Institute for Fundamental Research - Instituto de Física Teórica da UNESP, 01140-070, São Paulo, Brazil
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Yang F, Zhang J, Cisse EHM, Li DD, Guo LY, Xiang LS, Miao LF. Competitive Relationship Between Cleistocalyx operculatus and Syzygium jambos Under Well-Watered Conditions Transforms Into a Mutualistic Relationship Under Waterlogging Stress. FRONTIERS IN PLANT SCIENCE 2022; 13:869418. [PMID: 35755663 PMCID: PMC9231832 DOI: 10.3389/fpls.2022.869418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Competition and abiotic stress such as waterlogging (WL) represent main factors limiting plant growth and determining plant resistance and distribution patterns in wetland ecosystems. One of the basic steps for wetland restoration is to plant trees to ensure a quicker recovery and prevent erosion. Plant survival and adaptation are considered criteria of principal priority for the screening of plant species for wetland ecosystem restoration. WL influences plant species in wetlands via the deterioration of the plant root environment which leads to oxygen deficiency that affects plant growth, photosynthesis, respiration, and other metabolic processes. A suitable plant species was determined according to tolerance to WL during wetland vegetation recovery activities. Thus, two tree species (Cleistocalyx operculatus and Syzygium jambos) that showed a certain waterlogging tolerance were chosen to study their behaviors in different planting model and environmental conditions. Given that interspecific relationship should be considered during plant community construction, the eco-physiological adaptable mechanisms between these woody plants under well-watered condition and waterlogging stress were explored. Results showed that both species were waterlogging-tolerant species due to their ability to adapt to submergence conditions for 120 days. Moreover, C. operculatus possessed stronger tolerance to waterlogging stress because of a significant adventitious roots biomass accumulation. A competitive relationship was found between C. operculatus and S. jambos under well-watered condition, and C. operculatus showed better growth performance benefited from morphological responses (plant height, number of blade and leaf area) and endogenous hormone variations. In comparison, S. jambos suffered some negative effects when the well-watered mixed planting was used. However, the competitive relationship under well-watered condition was transformed into mutualistic relationship under waterlogging stress. The mixed planting under waterlogging condition significantly improved the tolerance of C. operculatus and S. jambos to waterlogging stress, compared with the monoculture., Especially, S. jambos showed improvements in root length, root surface area, and redox equilibration between lower levels of relative conductivity, malondialdehyde, and O 2 ⋅ - and had increased levels of non-enzymatic antioxidant components, such as reduced glutathione and soluble proteins. The interspecific relationship between C. operculatus and S. jambos was altered by waterlogging stress, and both showed improved tolerance to waterlogging stress. This study can provide a glimmer of light on suitable plant species selection and plant community construction during the revegetation activities in wetland zones. C. operculatus and S. jambos represent potential candidates in wetland restoration in a mixed planting model.
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Affiliation(s)
- Fan Yang
- School of Ecological and Environmental Sciences, Hainan University, Haikou, China
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou, China
| | - Juan Zhang
- School of Ecological and Environmental Sciences, Hainan University, Haikou, China
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou, China
| | - El-Hadji Malick Cisse
- School of Ecological and Environmental Sciences, Hainan University, Haikou, China
- School of Life Science, Hainan University, Haikou, China
| | - Da-Dong Li
- School of Ecological and Environmental Sciences, Hainan University, Haikou, China
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou, China
| | - Lu-Yao Guo
- School of Ecological and Environmental Sciences, Hainan University, Haikou, China
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou, China
| | - Li-Shan Xiang
- School of Ecological and Environmental Sciences, Hainan University, Haikou, China
| | - Ling-Feng Miao
- School of Ecological and Environmental Sciences, Hainan University, Haikou, China
- School of Plant Protection, Hainan University, Haikou, China
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3
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Ponge J. Communities, ecosystem engineers, and functional domains. Ecol Res 2021. [DOI: 10.1111/1440-1703.12247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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Ma F, Yang L, Lv T, Zuo Z, Zhao H, Fan S, Liu C, Yu D. The Biodiversity–Biomass Relationship of Aquatic Macrophytes Is Regulated by Water Depth: A Case Study of a Shallow Mesotrophic Lake in China. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.650001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The relationship between biodiversity and productivity (or biomass production) (BPR) has been a popular topic in macroecology and debated for decades. However, this relationship is poorly understood in macrophyte communities, and the mechanism of the BPR pattern of the aquatic macrophyte community is not clear. We investigated 78 aquatic macrophyte communities in a shallow mesotrophic freshwater lake in the middle and lower reaches of the Yangtze River in China. We analyzed the relationship between biodiversity (species richness, diversity, and evenness indices) and community biomass, and the effects of water environments and interspecific interactions on biodiversity–biomass patterns. Unimodal patterns between community biomass and diversity indices instead of evenness indices are shown, and these indicate the importance of both the number and abundance of species when studying biodiversity–biomass patterns under mesotrophic conditions. These patterns were moderated by species identity biologically and water depth environmentally. However, water depth determined the distribution and growth of species with different life-forms as well as species identities through environmental filtering. These results demonstrate that water depth regulates the biodiversity–biomass pattern of the aquatic macrophyte community as a result of its effect on species identity and species distribution. Our study may provide useful information for conservation and restoration of macrophyte vegetation in shallow lakes through matching water depth and species or life-form combinations properly to reach high ecosystem functions and services.
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Chaieb G, Wang X, Abdelly C, Michalet R. Shift from short‐term competition to facilitation with drought stress is due to a decrease in long‐term facilitation. OIKOS 2020. [DOI: 10.1111/oik.07528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ghassen Chaieb
- Faculty of Sciences of Bizerte, Univ. of Carthage Zarzouna Tunisia
- Univ. of Bordeaux, UMR CNRS 5805 EPOC, Allée Geoffroy Saint‐Hilaire – CS 50023 FR‐33615 Pessac France
| | - Xiangtai Wang
- State Key Laboratory of Grassland and Agro‐ecosystems, School of Life Sciences, Lanzhou Univ., Lanzhou Gansu PR China
| | - Chedly Abdelly
- Laboratory of Extremophiles Plants, Center of Biotechnology of Borj Cedria, 2050 Tunisia
| | - Richard Michalet
- Univ. of Bordeaux, UMR CNRS 5805 EPOC, Allée Geoffroy Saint‐Hilaire – CS 50023 FR‐33615 Pessac France
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6
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Do constrained immigration rates and high β diversity explain contrasting productivity-diversity patterns measured at different scales? Oecologia 2020; 194:481-490. [PMID: 32989572 DOI: 10.1007/s00442-020-04766-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 09/21/2020] [Indexed: 10/23/2022]
Abstract
The relationship between productivity and diversity is controversial because of disparity between unimodal and monotonic patterns, especially when occurring simultaneously at different scales. We used stream-side artificial channels to investigate how the availability of a major resource (leaf litter) affected stream invertebrate abundance and diversity at leaf-pack and whole-channel scales. At the larger scale, invertebrate diversity increased monotonically with increasing litter resource density, whereas at the smaller scale the relationship was hump-shaped, in keeping with reports in the literature. This divergence at higher resource levels suggests that multiple mechanisms may be operating. Our results indicate that consistently high species turnover (β diversity) caused the monotonic pattern because of a species-area or "sampling effect" in which new species accumulate with increasing number of samples. The hump-shaped pattern was due to constrained immigration because of a "dilution effect" in which a limited number of immigrants is spread out among the increasing number of available patches. We propose that the relationship between productivity or resource availability and α diversity is generally hump-shaped and the scale-dependent contrast in the relationship only arises where the species pool is large and β diversity is high. Differences in β diversity may, therefore, explain some of the contrasting patterns in the productivity-diversity relationship previously reported.We suggest that continuing immigration by rare taxa is important in sustaining species diversity when productivity is high. The hump-shaped pattern has implications for the impact of anthropogenic ecosystem enrichment on species diversity.
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Wang Z, Chiarucci A, Arratia JF. Integrative models explain the relationships between species richness and productivity in plant communities. Sci Rep 2019; 9:13730. [PMID: 31551462 PMCID: PMC6760178 DOI: 10.1038/s41598-019-50016-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 09/04/2019] [Indexed: 11/17/2022] Open
Abstract
The relationship between plant productivity and species richness is one of the most debated and important issues in ecology. Ecologists have found numerous forms of this relationship and its underlying processes. However, theories and proposed drivers have been insufficient to completely explain the observed variation in the forms of this relationship. Here, we developed and validated integration models capable of combining twenty positive or negative processes affecting the relationship. The integration models generated the classic humped, asymptotic, positive, negative and irregular forms and other intermediate forms of the relationship between plant richness and productivity. These forms were linked to one another and varied according to which was considered the dependent variable. The total strengths of the different positive and negative processes are the determinants of the forms of the relationship. Positive processes, such as resource availability and species pool effects, can offset the negative effects of disturbance and competition and change the relationship. This combination method clarifies the reasons for the diverse forms of the relationship and deepens our understanding of the interactions among processes.
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Affiliation(s)
- Zhenhong Wang
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Chang'an University, Xi'an, China.
- School of Environmental Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Alessandro Chiarucci
- Department of Biological, Geological and Environmental Science, University of Bologna, Via Irnerio, 42-40126, Bologna, Italy
| | - Juan F Arratia
- AGMUS Institute of Mathematics, Caribbean Computing Center for Excellence, 21150, San Juan, Puerto Rico, USA
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8
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Responses of different herb life-history groups to a dominant shrub species along a dune stabilization gradient. Basic Appl Ecol 2019. [DOI: 10.1016/j.baae.2019.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Liancourt P, Le Bagousse-Pinguet Y, Rixen C, Dolezal J. SGH: stress or strain gradient hypothesis? Insights from an elevation gradient on the roof of the world. ANNALS OF BOTANY 2017; 120:29-38. [PMID: 28444363 PMCID: PMC5737727 DOI: 10.1093/aob/mcx037] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/15/2017] [Indexed: 06/01/2023]
Abstract
BACKGROUND AND AIMS The stress gradient hypothesis (SGH), the view that competition prevails in undisturbed and productive environments, and shifts to facilitation in disturbed or stressful environments, has become a central paradigm in ecology. However, an alternative view proposes that the relationship between biotic interactions and environmental severity should be unimodal instead of monotonic. Possible causes of discrepancies between these two views were examined in the high elevation desert of the arid Trans-Himalayas. METHODS A putative nurse species and its associated plant community was surveyed over its entire elevation range, spanning from alpine to desert vegetation belts. The results were analysed at the community level (vegetation cover and species richness), considering the distinction between the intensity and the importance of biotic interactions. Interactions at the species level (pairwise interactions) were also considered, i.e. the variation of biotic interactions within the niche of a species, for which the abundance (species cover) and probability of occurrence (presence/absence) for the most widespread species along the gradient were distinguished. KEY RESULTS Overall, facilitation was infrequent in our study system; however, it was observed for the two most widespread species. At the community level, the intensity and importance of biotic interactions showed a unimodal pattern. The departure from the prediction of the SGH happened abruptly where the nurse species entered the desert vegetation belt at the lowest elevation. This abrupt shift was attributed to the turnover of species with contrasting tolerances. At the species level, however, facilitation increased consistently as the level of stress increases and individuals deviate from their optimum (increasing strain). CONCLUSION While the stress gradient hypothesis was not supported along our elevation gradient at the community level, the strain gradient hypothesis, considering how species perceive the ambient level of stress and deviate from their optimum, provided a parsimonious explanation for the outcome of plant-plant interactions at both scales.
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Affiliation(s)
- Pierre Liancourt
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, 379 82 Trebon, Czech Republic
| | - Yoann Le Bagousse-Pinguet
- Departamento de Biología y Geología, Física y Química Inorgánica, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, C/ Tulipán s/n, 28933 Móstoles, Spain
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland
| | - Jiri Dolezal
- Institute of Botany, Czech Academy of Sciences, Dukelská 135, 379 82 Trebon, Czech Republic
- Department of Botany, Faculty of Science, University of South Bohemia, Na Zlate stoce 1, 370 05 Ceske Budejovice, Czech Republic
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10
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Vergnon R, Ooi MKJ, Freckleton RP. Complex Relationships between Competing Guilds along Large-Scale Environmental Gradients. Am Nat 2017; 189:407-421. [PMID: 28350502 DOI: 10.1086/690765] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Despite much research over the past 30 years, there is still little general understanding of how the outcomes of interactions vary along environmental gradients, particularly at large geographic scales. A simple expectation is that decreasing environmental quality should reduce densities of competitors and hence the effects of competition should weaken in poorer environments. A counterintuitive consequence is that associations between densities of competitors might change from negative to positive as environments decrease in quality. Here we test these predictions in a set of vascular plant communities where perennial species share space and resources with less competitive annuals. We surveyed nine gray dune communities annually for 5 years along a cross-European latitudinal gradient of habitat quality. We find that densities of annual and perennial species are negatively correlated at the high-quality end of the gradient, while at the low-quality end, guild densities are uncorrelated or positively correlated, consistent with a weakening of competition linked to increasing environmental limitations. Our results suggest that even simple interactions can give rise to nonobvious changes in species associations along environmental gradients. They highlight that understanding the outcome of species interactions may require explicit characterization of their changing intensity with environmental quality and that the factors limiting species' codistribution can vary along environmental gradients.
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11
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Zhang WP, Jia X, Wang GX. Facilitation among plants can accelerate density-dependent mortality and steepen self-thinning lines in stressful environments. OIKOS 2017. [DOI: 10.1111/oik.03983] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wei-Ping Zhang
- Beijing Key Laboratory of Biodiversity and Organic Farming, Key Laboratory of Plant and Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural Univ.; Beijing PR China
| | - Xin Jia
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry Univ., CN-100083; Beijing PR China
| | - Gen-Xuan Wang
- College of Life Sciences, Zhejiang Univ.; Hangzhou PR China
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12
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Ehlers BK, Damgaard CF, Laroche F. Intraspecific genetic variation and species coexistence in plant communities. Biol Lett 2017; 12:20150853. [PMID: 26790707 DOI: 10.1098/rsbl.2015.0853] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many studies report that intraspecific genetic variation in plants can affect community composition and coexistence. However, less is known about which traits are responsible and the mechanisms by which variation in these traits affect the associated community. Focusing on plant-plant interactions, we review empirical studies exemplifying how intraspecific genetic variation in functional traits impacts plant coexistence. Intraspecific variation in chemical and architectural traits promotes species coexistence, by both increasing habitat heterogeneity and altering competitive hierarchies. Decomposing species interactions into interactions between genotypes shows that genotype × genotype interactions are often intransitive. The outcome of plant-plant interactions varies with local adaptation to the environment and with dominant neighbour genotypes, and some plants can recognize the genetic identity of neighbour plants if they have a common history of coexistence. Taken together, this reveals a very dynamic nature of coexistence. We outline how more traits mediating plant-plant interactions may be identified, and how future studies could use population genetic surveys of genotype distribution in nature and methods from trait-based ecology to better quantify the impact of intraspecific genetic variation on plant coexistence.
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Affiliation(s)
- Bodil K Ehlers
- Department of Bioscience, Aarhus University, Vejlsøvej 25, Silkeborg 8600, Denmark
| | - Christian F Damgaard
- Department of Bioscience, Aarhus University, Vejlsøvej 25, Silkeborg 8600, Denmark
| | - Fabien Laroche
- CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul Valéry Montpellier-EPHE, 1919 route de Mende, Montpellier 34293, France IRSTEA, U.R. Ecosystèmes Forestiers, Domaine des Barres, Nogent-sur-Vernisson 45290, France Sveriges Lantbruksuniversitet, Ekologicentrum, Ulls väg 16, Ultuna, Uppsala, Sweden
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13
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Malatesta L, Tardella FM, Piermarteri K, Catorci A. Evidence of Facilitation Cascade Processes as Drivers of Successional Patterns of Ecosystem Engineers at the Upper Altitudinal Limit of the Dry Puna. PLoS One 2016; 11:e0167265. [PMID: 27902757 PMCID: PMC5130256 DOI: 10.1371/journal.pone.0167265] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 11/13/2016] [Indexed: 11/19/2022] Open
Abstract
Facilitation processes constitute basic elements of vegetation dynamics in harsh systems. Recent studies in tropical alpine environments demonstrated how pioneer plant species defined as “ecosystem engineers” are capable of enhancing landscape-level richness by adding new species to the community through the modification of microhabitats, and also provided hints about the alternation of different ecosystem engineers over time. Nevertheless, most of the existing works analysed different ecosystem engineers separately, without considering the interaction of different ecosystem engineers. Focusing on the altitudinal limit of Peruvian Dry Puna vegetation, we hypothesized that positive interactions structure plant communities by facilitation cascades involving different ecosystem engineers, determining the evolution of the microhabitat patches in terms of abiotic resources and beneficiary species hosted. To analyze successional mechanisms, we used a “space-for-time” substitution to account for changes over time, and analyzed data on soil texture, composition, and temperature, facilitated species and their interaction with nurse species, and surface area of engineered patches by means of chemical analyses, indicator species analysis, and rarefaction curves. A successional process, resulting from the dynamic interaction of different ecosystem engineers, which determined a progressive amelioration of soil conditions (e.g. nitrogen and organic matter content, and temperature), was the main driver of species assemblage at the community scale, enhancing species richness. Cushion plants act as pioneers, by starting the successional processes that continue with shrubs and tussocks. Tussock grasses have sometimes been found to be capable of creating microhabitat patches independently. The dynamics of species assemblage seem to follow the nested assemblage mechanism, in which the first foundation species to colonize a habitat provides a novel substrate for colonization by other foundation species through a facilitation cascade process.
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Affiliation(s)
- Luca Malatesta
- School of Advanced Studies, University of Camerino, Camerino, Macerata, Italy
| | - Federico Maria Tardella
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Macerata, Italy
- * E-mail:
| | - Karina Piermarteri
- School of Advanced Studies, University of Camerino, Camerino, Macerata, Italy
| | - Andrea Catorci
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Macerata, Italy
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14
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Wang J, Cheng Y, Zhang C, Zhao Y, Zhao X, Von Gadow K. Relationships between tree biomass productivity and local species diversity. Ecosphere 2016. [DOI: 10.1002/ecs2.1562] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Juan Wang
- Key Laboratory for Forest Resources and Ecosystem Processes of BeijingBeijing Forestry University Beijing 100083 China
| | - Yanxia Cheng
- Key Laboratory for Forest Resources and Ecosystem Processes of BeijingBeijing Forestry University Beijing 100083 China
| | - Chunyu Zhang
- Key Laboratory for Forest Resources and Ecosystem Processes of BeijingBeijing Forestry University Beijing 100083 China
| | - Yazhou Zhao
- College of Landscape ArchitectureBeijing University of Agriculture Beijing 102206 China
| | - Xiuhai Zhao
- Key Laboratory for Forest Resources and Ecosystem Processes of BeijingBeijing Forestry University Beijing 100083 China
| | - Klaus Von Gadow
- Faculty of Forestry and Forest EcologyGeorg‐August‐University Göttingen Göttingen D‐37077 Germany
- Department of Forest and Wood ScienceUniversity of Stellenbosch Stellenbosch 7600 South Africa
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15
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Modeling the relative importance of ecological factors in exotic invasion: The origin of competitors matters, but disturbance in the non-native range tips the balance. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2016.05.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Michalet R, Pugnaire FI. Facilitation in communities: underlying mechanisms, community and ecosystem implications. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12602] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Francisco I. Pugnaire
- Estación Experimental de Zonas Áridas Consejo Superior de Investigaciones Científicas Almería Spain
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17
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Lin Y, Berger U, Yue M, Grimm V. Asymmetric facilitation can reduce size inequality in plant populations resulting in delayed density-dependent mortality. OIKOS 2015. [DOI: 10.1111/oik.02593] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yue Lin
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e DE-04103 Leipzig Germany
- Helmholtz Centre for Environmental Research − UFZ; Dept of Ecological Modelling; Permoserstraße 15 DE-04318 Leipzig Germany
- School of Life Science, Northwest University; CN-710069 Xi'an China
| | - Uta Berger
- Inst. of Forest Growth and Computer Science, Technische Universität Dresden; PO 1117, DE-01735 Tharandt Germany
| | - Ming Yue
- School of Life Science, Northwest University; CN-710069 Xi'an China
| | - Volker Grimm
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e DE-04103 Leipzig Germany
- Helmholtz Centre for Environmental Research − UFZ; Dept of Ecological Modelling; Permoserstraße 15 DE-04318 Leipzig Germany
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18
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Yang Z, Liu X, Zhou M, Ai D, Wang G, Wang Y, Chu C, Lundholm JT. The effect of environmental heterogeneity on species richness depends on community position along the environmental gradient. Sci Rep 2015; 5:15723. [PMID: 26508413 PMCID: PMC4623746 DOI: 10.1038/srep15723] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 10/01/2015] [Indexed: 11/09/2022] Open
Abstract
Environmental heterogeneity is among the most important factors governing community structure. Besides the widespread evidence supporting positive relationships between richness and environmental heterogeneity, negative and unimodal relationships have also been reported. However, few studies have attempted to test the role of the heterogeneity on species richness after removing the confounding effect of resource availability or environmental severity. Here we constructed an individual-based spatially explicit model incorporating a long-recognized tradeoff between competitive ability and stress-tolerance ability of species. We explored the impact of the level of resource availability (i.e. the position of the community along a gradient of environmental severity) on the heterogeneity-diversity relationship (HDR). The results indicate that the shape of HDR depends on the community position along the environmental gradient: at either end of the gradient of environmental severity, a positive HDR occurred, whereas at the intermediate levels of the gradient, a unimodal HDR emerged. Our exploration demonstrates that resource availability/environmental severity should be considered as a potential factor influencing the shape of the HDR. Our theoretical predictions represent hypotheses in need of further empirical study.
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Affiliation(s)
- Zhiyong Yang
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xueqi Liu
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Mohua Zhou
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Dexiecuo Ai
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Gang Wang
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Youshi Wang
- Ministry of Education Key Laboratory of Western China’s Environmental Systems, Research School of Arid Environment and Climate Change, Lanzhou University, Lanzhou, 730000, China
| | - Chengjin Chu
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
- SYSU-Alberta Joint Lab for Biodiversity Conservation, State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Jeremy T. Lundholm
- Department of Biology/Environmental Studies Program, Saint Mary’s University, Halifax, Nova Scotia, Canada B3H3C3
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19
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Bråthen KA, Lortie C. A portfolio effect of shrub canopy height on species richness in both stressful and competitive environments. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12458] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kari Anne Bråthen
- Department of Arctic and Marin Biology UiT‐ Arctic University of Norway N‐9037 Tromsø Norway
| | - Christopher Lortie
- Department of Biology York University 4700 Keele St. Toronto ON M3J 1P3 Canada
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20
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Michalet R, Brooker RW, Lortie CJ, Maalouf JP, Pugnaire FI. Disentangling direct and indirect effects of a legume shrub on its understorey community. OIKOS 2015. [DOI: 10.1111/oik.01819] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Richard Michalet
- Univ. of Bordeaux, U.M.R. 5805 EPOC; Avenue des Facultés FR-33405 Talence cedex France
| | - Rob W. Brooker
- The James Hutton Inst.; Craigiebuckler, Aberdeen AB15 8QH Scotland UK
| | | | - Jean-Paul Maalouf
- Univ. of Bordeaux, U.M.R. 5805 EPOC; Avenue des Facultés FR-33405 Talence cedex France
| | - Francisco I. Pugnaire
- Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas; Carretera de Sacramento s/n La Cañada de San Urbano ES-04120 Almería Spain
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21
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Malanson GP, Resler LM. Neighborhood functions alter unbalanced facilitation on a stress gradient. J Theor Biol 2014; 365:76-83. [PMID: 25445188 DOI: 10.1016/j.jtbi.2014.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 09/17/2014] [Accepted: 10/02/2014] [Indexed: 11/16/2022]
Abstract
The stress-gradient hypothesis states that individual and species competitive and facilitative effects change in relative importance or intensity along environmental gradients of stress. The importance of the number of facilitators in the neighborhood of a potential beneficiary has not been explored. Evenly distributed and stress-correlated facilitation and the increase in the intensity of facilitation with neighbors as linear, logarithmic, and unimodal functions is simulated for two hypothetical species, both of which improve the local environment. The mutualism is unbalanced in that the establishment of one species is enhanced by neighbors more than the other. Compared to no facilitation or evenly distributed facilitation, the stress gradient produces more edges in the spatially advancing population, more overall intensity of facilitation, and more individuals further advanced into the area of higher stress; the more enhanced species has increased population relative to the other - to the point where they are equal. Among three neighborhood functions, little difference exists in outcomes between the linear and logarithmic functions, but the unimodal function, which shifts peak facilitation intensity to fewer neighbors, increases the above state variables more than the differences between the even and stress gradient facilitation scenarios; the population of the beneficiary species exceeds that of the other. Different neighborhood functions change the effects of spatial pattern on the biological outcome. The unbalanced mutualism may be important where additional species alter the basic interaction in the high stress area of the environmental gradient, such as ecotones where the spatial pattern becomes central to facilitation.
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Affiliation(s)
- George P Malanson
- Department of Geographical & Sustainability Sciences, University of Iowa, Iowa City, IA 52242 USA and Division of Environmental Biology, National Science Foundation, 4201 Wilson Blvd., Arlington, VA 22230, USA.
| | - Lynn M Resler
- Department of Geography, Virginia Tech, Blacksburg, VA 24061, USA
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22
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Shah MA, Callaway RM, Shah T, Houseman GR, Pal RW, Xiao S, Luo W, Rosche C, Reshi ZA, Khasa DP, Chen S. Conyza canadensis suppresses plant diversity in its nonnative ranges but not at home: a transcontinental comparison. THE NEW PHYTOLOGIST 2014; 202:1286-1296. [PMID: 24548283 DOI: 10.1111/nph.12733] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 01/21/2014] [Indexed: 05/28/2023]
Abstract
The impact of invasive species across their native and nonnative ranges is poorly quantified and this impedes a complete understanding of biological invasions. We compared the impact of the native North American plant, Conyza canadensis, which is invasive to Eurasia, on species richness at home and in a number of introduced regions through well replicated transcontinental field studies, glasshouse experiments and individual-based models. Our results demonstrated mostly negative relationships between C. canadensis abundance and native species richness in nonnative ranges, but either positive or no relationships in its native North American range. In glasshouse experiments, the total biomass of Conyza was suppressed more by species from its native range than by species from regions where it is nonnative, but the effects of Conyza on other species did not show a consistent biogeographical pattern. Finally, individual-based models led to the exclusion of Conyza from North American scenarios but to high abundances in scenarios with species from the nonnative ranges of Conyza. We illustrate biogeographical differences in the impact of an invader across regional scales and suggest that inherent differences in one specific aspect of competitive ability, tolerance to the effects of other species, may play some role in these differences.
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Affiliation(s)
- Manzoor A Shah
- Department of Botany, University of Kashmir, Srinagar, 190 006, Jammu & Kashmir, India
| | - Ragan M Callaway
- Division of Biological Sciences and the Institute on Ecosystems, The University of Montana, Missoula, MT, 59812, USA
| | - Tabasum Shah
- Department of Botany, University of Kashmir, Srinagar, 190 006, Jammu & Kashmir, India
| | - Gregory R Houseman
- Department of Biological Sciences, Wichita State University, Wichita, KS, USA
| | - Robert W Pal
- Division of Biological Sciences and the Institute on Ecosystems, The University of Montana, Missoula, MT, 59812, USA
- Faculty of Sciences, University of Pecs, Ifjusagu, 6, H-7624, Pecs, Hungary
| | - Sa Xiao
- Division of Biological Sciences and the Institute on Ecosystems, The University of Montana, Missoula, MT, 59812, USA
- Key Laboratory of Cell Activities and Stress Adaptations (Ministry of Education), School of Life Science, Lanzhou University, Lanzhou, Gansu People's Republic of China
| | - Wenbo Luo
- Key Laboratory for Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, China
| | - Christoph Rosche
- Institute of Biology/Geobotany and Botanical Garden, Martin Luther University of Halle-Wittenberg, D-06108, Halle/Saale, Germany
| | - Zafar A Reshi
- Department of Botany, University of Kashmir, Srinagar, 190 006, Jammu & Kashmir, India
| | - Damase P Khasa
- Centre for Forest Research and Institute for Systems and Integrative Biology, Université Laval, Quebec City, QC, GIV0A6, Canada
| | - Shuyan Chen
- Division of Biological Sciences and the Institute on Ecosystems, The University of Montana, Missoula, MT, 59812, USA
- Key Laboratory of Cell Activities and Stress Adaptations (Ministry of Education), School of Life Science, Lanzhou University, Lanzhou, Gansu People's Republic of China
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23
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Wang Y, Yang Z, Zhou S, Soininen J, Ai D, Li Y, Chu C. The effect of positive interactions on temporal turnover of community composition along an environmental gradient. PLoS One 2013; 8:e78698. [PMID: 24265708 PMCID: PMC3827060 DOI: 10.1371/journal.pone.0078698] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 09/16/2013] [Indexed: 11/18/2022] Open
Abstract
It has been demonstrated that the interplay between negative and positive interactions simultaneously shapes community structure and composition. However, few studies have attempted to examine the effect of facilitation on compositional changes in communities through time. Additionally, due to the difficulties in collecting the long-term data, it would be useful to indicate the rate of temporal turnover using a readily obtainable metric. Using an individual-based model incorporating plant strategies, we examined the role of facilitation on the temporal turnover of communities located at different positions along an environmental gradient for three model scenarios: CM without facilitation; CFM-U, a unimodal relationship between facilitation and environmental severity; and CFM-L, a positively linear relationship between facilitation and environmental severity. Our results demonstrated that facilitation could increase, decrease or have no remarkable effect on temporal turnover. The specific outcome depended on the location of the focal community across the environmental gradient and the model employed. Compared with CM, the inclusion of positive interactions (i.e. CFM-U and CFM-L), at intermediate environmental stress levels (such as S = 0.7 and 0.8) resulted in lower Bray-Curtis similarity values; at other severity levels, facilitation slowed down (such as S = 0.3 and 0.4 at low to medium stress levels, and S = 0.9 at high stress levels) or had only a subtle effect (such as at S = 0.1) on temporal turnover. We also found that the coefficient of variation (CV) in species abundances and the rate of temporal variability showed a significant quadratic relationship. Our theoretical analysis contributes to the understanding of factors driving temporal turnover in biotic communities, and presents a potential metric (i.e. CV in species abundances) assessing the consequences of ongoing environmental change on community structure.
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Affiliation(s)
- Youshi Wang
- Ministry of Education Key Laboratory of Western China’s Environmental Systems, Research School of Arid Environment and Climate Change, Lanzhou University, Lanzhou, China
| | - Zhiyong Yang
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Shurong Zhou
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of life Sciences, Fudan University, Shanghai, China
| | - Janne Soininen
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Dexiecuo Ai
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Yali Li
- Xikehe Sire Breeding Farm of Euler Sheep of Maqu County in the Gansu Province, Maqu, China
| | - Chengjin Chu
- State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
- * E-mail:
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24
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Xiao S, Ni G, Callaway RM. Models of experimentally derived competitive effects predict biogeographical differences in the abundance of invasive and native plant species. PLoS One 2013; 8:e78625. [PMID: 24265701 PMCID: PMC3827048 DOI: 10.1371/journal.pone.0078625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 09/13/2013] [Indexed: 11/18/2022] Open
Abstract
Mono-dominance by invasive species provides opportunities to explore determinants of plant distributions and abundance; however, linking mechanistic results from small scale experiments to patterns in nature is difficult. We used experimentally derived competitive effects of an invader in North America, Acroptilon repens, on species with which it co-occurs in its native range of Uzbekistan and on species with which it occurs in its non-native ranges in North America, in individual-based models. We found that competitive effects yielded relative abundances of Acroptilon and other species in models that were qualitatively similar to those observed in the field in the two ranges. In its non-native range, Acroptilon can occur in nearly pure monocultures at local scales, whereas such nearly pure stands of Acroptilon appear to be much less common in its native range. Experimentally derived competitive effects of Acroptilon on other species predicted Acroptilon to be 4-9 times more proportionally abundant than natives in the North American models, but proportionally equal to or less than the abundance of natives in the Eurasian models. Our results suggest a novel way to integrate complex combinations of interactions simultaneously, and that biogeographical differences in the competitive effects of an invader correspond well with biogeographical differences in abundance and impact.
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Affiliation(s)
- Sa Xiao
- Key Laboratory of Cell Activities and Stress Adaptations (Ministry of Education), School of Life Science, Lanzhou University, Lanzhou, Gansu, People's Republic of China
| | - Guangyan Ni
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Ragan M. Callaway
- Division of Biological Sciences and the Institute on Ecosystems, The University of Montana, Missoula, Montana, United States of America
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25
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Xiao S, Zhao L, Zhang JL, Wang XT, Chen SY. The integration of facilitation into the neutral theory of community assembly. Ecol Modell 2013. [DOI: 10.1016/j.ecolmodel.2012.12.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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Comparing neutral and trade-off community models in shaping the community biomass-diversity relationship under different disturbance levels. Bull Math Biol 2013; 75:213-22. [PMID: 23307234 DOI: 10.1007/s11538-012-9800-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/19/2012] [Indexed: 10/27/2022]
Abstract
Among numerous mechanisms shaping the unimodal relationship between diversity and community biomass, the trade-off model of "CRS" theory is the most famous one. However, recent researches indicate that this relationship may also emerge under the neutral model where all species are identical with each other. By using an individual-based spatially-explicit model, we evaluated the underlying mechanisms shaping this curve for both models under different disturbance levels. We found unimodal relationships emerged for both models at low and medium disturbance levels; the richness for the trade-off community was lower than the neutral community for most of the environment severity levels, especially at the benign environment due to the strong competitive exclusions among species. Whereas under high disturbance level, the positive relationships emerged for both models; both communities had similar richness with their curves nearly overlapped with each other, that is, because the high disturbance intensity strongly decreased the competitive exclusions within the trade-off community. Our results indicate that although the underlying mechanisms are totally different, both models will produce the similar relationship between diversity and community biomass under different disturbance levels.
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27
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Xiao S, Callaway RM, Newcombe G, Aschehoug ET. Models of experimental competitive intensities predict home and away differences in invasive impact and the effects of an endophytic mutualist. Am Nat 2012; 180:707-18. [PMID: 23149396 DOI: 10.1086/668008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Understanding the role of competition in the organization of communities is limited in part by the difficulty of extrapolating the outcomes of small-scale experiments to how such outcomes might affect the distribution and abundance of species. We modeled the community-level outcomes of competition, using experimentally derived competitive effects and responses between an exotic invasive plant, Centaurea stoebe, and species from both its native and nonnative ranges and using changes in these effects and responses elicited by experimentally establishing symbioses between C. stoebe and fungal endophytes. Using relative interaction intensities (RIIs) and holding other life-history factors constant, individual-based and spatially explicit models predicted competitive exclusion of all but one North American species but none of the European species, regardless of the endophyte status of C. stoebe. Concomitantly, C. stoebe was eliminated from the models with European natives but was codominant in models with North American natives. Endophyte symbiosis predicted increased dominance of C. stoebe in North American communities but not in European communities. However, when experimental variation was included, some of the model outcomes changed slightly. Our results are consistent with the idea that the effects of competitive intensity and mutualisms measured at small scales have the potential to play important roles in determining the larger-scale outcomes of invasion and that the stabilizing indirect effects of competition may promote species coexistence.
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Affiliation(s)
- Sa Xiao
- Key Laboratory of Arid and Grassland Agroecology, School of Life Science, Lanzhou University, People's Republic of China
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28
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Maalouf JP, Le Bagousse-Pinguet Y, Marchand L, Touzard B, Michalet R. The interplay of stress and mowing disturbance for the intensity and importance of plant interactions in dry calcareous grasslands. ANNALS OF BOTANY 2012; 110:821-8. [PMID: 22782241 PMCID: PMC3423810 DOI: 10.1093/aob/mcs152] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS There is still debate regarding the direction and strength of plant interactions under intermediate to high levels of stress. Furthermore, little is known on how disturbance may interact with physical stress in unproductive environments, although recent theory and models have shown that this interplay may induce a collapse of plant interactions and diversity. The few studies assessing such questions have considered the intensity of biotic interactions but not their importance, although this latter concept has been shown to be very useful for understanding the role of interactions in plant communities. The objective of this study was to assess the interplay between stress and disturbance for plant interactions in dry calcareous grasslands. METHODS A field experiment was set up in the Dordogne, southern France, where the importance and intensity of biotic interactions undergone by four species were measured along a water stress gradient, and with and without mowing disturbance. KEY RESULTS The importance and intensity of interactions varied in a very similar way along treatments. Under undisturbed conditions, plant interactions switched from competition to neutral with increasing water stress for three of the four species, whereas the fourth species was not subject to any significant biotic interaction along the gradient. Responses to disturbance were more species-specific; for two species, competition disappeared with mowing in the wettest conditions, whereas for the two other species, competition switched to facilitation with mowing. Finally, there were no significant interactions for any species in the disturbed and driest conditions. CONCLUSIONS At very high levels of stress, plant performances become too weak to allow either competition or facilitation and disturbance may accelerate the collapse of interactions in dry conditions. The results suggest that the importance and direction of interactions are more likely to be positively related in stressful environments.
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Affiliation(s)
- Jean-Paul Maalouf
- UMR BIOGECO INRA, Ecologie des Communautés, Université Bordeaux, Bât. B2 RDC Est, Talence, France.
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Michalet R, Xiao S, Touzard B, Smith DS, Cavieres LA, Callaway RM, Whitham TG. Phenotypic variation in nurse traits and community feedbacks define an alpine community. Ecol Lett 2011; 14:433-43. [PMID: 21366815 DOI: 10.1111/j.1461-0248.2011.01605.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Much is known about facilitation, but virtually nothing about the underlying genetic and evolutionary consequences of this important interaction. We assessed the potential of phenotypic differences in facilitative effects of a foundation species to determine the composition of an Alpine community in Arizona. Two phenotypes of Geum rossii occur along a gradient of disturbance, with 'tight' competitive cushions in stable conditions and 'loose' facilitative cushions in disturbed conditions. A common-garden study suggested that field-based traits may have a genetic basis. Field experiments showed that the reproductive fitness of G. rossii cushions decreased with increasing facilitation. Finally, using a dual-lattice model we showed that including the cost and benefit of facilitation may contribute to the co-occurrence of genotypes with contrasting facilitative effects. Our results indicate that changes in community composition due to phenotypic differences in facilitative effects of a foundation species may in turn affect selective pressures on the foundation species.
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Affiliation(s)
- Richard Michalet
- University Bordeaux 1, UMR INRA 1202 BIOGECO, 33405 Talence, France.
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30
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Jia X, Dai XF, Shen ZX, Zhang JY, Wang GX. Facilitation can maintain clustered spatial pattern of plant populations during density-dependent mortality: insights from a zone-of-influence model. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2010.18674.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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Xu J, Michalet R, Zhang JL, Wang G, Chu CJ, Xiao S. Assessing facilitative responses to a nurse shrub at the community level: the example of Potentilla fruticosa in a sub-alpine grassland of northwest China. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12:780-787. [PMID: 20701701 DOI: 10.1111/j.1438-8677.2009.00271.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Biotic interaction studies have revealed a large discrepancy among experiments in target responses to the effects of neighbours, which may in part be due to both high species-specificity of plant responses and low number of target species used in experiments. Our aim was to assess facilitative responses at the community level and the role of both functional groups and ecological attributes of target species. In a sub-alpine grassland on the eastern Tibet plateau, we assessed growth responses of all species in the community to removal of a dominant shrub. We also measured changes in the main environmental variables. Species responses were analysed by functional group and in relation to their mean regional altitudinal distribution. All significant interactions were positive and affected one-third of the total species richness of the community. All functional groups were facilitated but forbs were less strongly facilitated than in the two other groups. High-alpine species were less strongly facilitated than low-sub-alpine species, but the strength of this relationship was weaker than that reported in previous work. There was evidence of a decrease in extreme temperatures below the canopy of the shrub but no variations in soil moisture. We conclude that the highly stressful conditions induced by the dry continental climate of the eastern Tibet plateau are a main driver of the exclusive dominance of positive interactions. Assessing interactive responses at the community level is likely to provide a useful tool to better understand the role of biotic interactions in community responses to environmental changes.
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Affiliation(s)
- J Xu
- MOE Key Laboratory of Arid and Grassland Ecology, School of Life Science, Lanzhou University, Lanzhou, China.
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