scholarly journals Linking spatial self-organization to community assembly and biodiversity

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Bidesh K Bera ◽  
Omer Tzuk ◽  
Jamie J R Bennett ◽  
Ehud Meron

Temporal shifts to drier climates impose environmental stresses on plant communities that may result in community reassembly and threatened ecosystem services, but also may trigger self-organization in spatial patterns of biota and resources, which act to relax these stresses. The complex relationships between these counteracting processes - community reassembly and spatial self-organization - have hardly been studied. Using a spatio-temporal model of dryland plant communities and a trait-based approach, we study the response of such communities to increasing water-deficit stress. We first show that spatial patterning acts to reverse shifts from fast-growing species to stress-tolerant species, as well as to reverse functional-diversity loss. We then show that spatial self-organization buffers the impact of further stress on community structure. Finally, we identify multistability ranges of uniform and patterned community states and use them to propose forms of non-uniform ecosystem management that integrate the need for provisioning ecosystem services with the need to preserve community structure.

2021 ◽  
Author(s):  
Ehud Meron ◽  
Bidesh K Bera ◽  
Omer Tzuk ◽  
Jamie J. R. Bennett

Drier climates impose environmental stresses on plant communities that may result in community reassembly and threatened ecosystem services, but also may trigger self-organization in spatial patterns of biota and resources, which act to relax these stresses. The complex relationships between these counteracting processes -- community reassembly and spatial self-organization -- have hardly been studied. Using a spatio-temporal model of dryland plant communities and a trait-based approach, we study the response of such communities to imposed water stress of increasing degrees. We first show that spatial patterning acts to reverse shifts from fast-growing species to stress-tolerant species, as well as to reverse functional-diversity loss. We then show that spatial re-patterning buffers the impact of further stress on community structure. Finally, we identify multistability ranges of uniform and patterned community states and use them to propose forms of non-uniform ecosystem management that integrate the need for provisioning ecosystem services with the need to preserve community structure.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Malin Olofsson ◽  
James G. Hagan ◽  
Bengt Karlson ◽  
Lars Gamfeldt

Abstract Aquatic phytoplankton experience large fluctuations in environmental conditions during seasonal succession and across salinity gradients, but the impact of this variation on their diversity is poorly understood. We examined spatio-temporal variation in nano- and microphytoplankton (> 2 µm) community structure using almost two decades of light-microscope based monitoring data. The dataset encompasses 19 stations that span a salinity gradient from 2.8 to 35 along the Swedish coastline. Spatially, both regional and local phytoplankton diversity increased with broad-scale salinity variation. Diatoms dominated at high salinity and the proportion of cyanobacteria increased with decreasing salinity. Temporally, cell abundance peaked in winter-spring at high salinity but in summer at low salinity. This was likely due to large filamentous cyanobacteria blooms that occur in summer in low salinity areas, but which are absent in higher salinities. In contrast, phytoplankton local diversity peaked in spring at low salinity but in fall and winter at high salinity. Whilst differences in seasonal variation in cell abundance were reasonably well-explained by variation in salinity and nutrient availability, variation in local-scale phytoplankton diversity was poorly predicted by environmental variables. Overall, we provide insights into the causes of spatio-temporal variation in coastal phytoplankton community structure while also identifying knowledge gaps.


2020 ◽  
Author(s):  
Andrew Nicholas Kadykalo ◽  
Kris Johnson ◽  
Scott McFatridge ◽  
C. Scott Findlay

Although agricultural “best (or beneficial) management practices” (BMPs) first emerged to mitigate agro-environmental resource challenges, they may also enhance ‘non-provisioning’ ecosystem services. The enthusiasm for adopting BMPs partially depends on evidence that doing so will lead to agro-environmental benefits while not substantially reducing crop productivity or farmer income. We survey and synthesize evidence in the existing literature to document the joint effects on agricultural crop yield and 12 ecosystem service (ES) associated with implementation of 5 agricultural BMPs (crop rotations, cover crops, nutrient management, perennial vegetated buffers, reduced or no tillage). We also analyze the prevalence of co-benefits (‘win-win’), tradeoffs, and co-costs (‘lose-lose’) outcomes. On the basis of a set of contextual variables we then develop empirical models that predict the likelihood of co-benefits relative to tradeoffs, and co-costs. We found thirty-six studies investigating 141 combinations of crop yields and non-provisioning ES outcomes (YESs) in the relevant literatures covering the period 1983-2016. The scope of the review is global, but included studies are geographically concentrated in the U.S. Corn Belt (Midwestern United States). In the literature sample, reporting of co-benefits (26%) was much more prevalent than reporting of co-costs (4%) between yields and ES. Tradeoffs most often resulted in a reduction in crop yields and an increase in ES (28%); this was marginally greater than studies reporting a neutral influence on crop yields and an increase in ES (26%). Other Y/ES combinations were uncommon. Mixed-effects models indicated reduced tillage and crop rotations had generally positive associations with YESs. Temporal scale was an informative predictor suggesting studies with longer time scales resulted in greater positive outcomes on YESs, on average. Our results are a step towards identifying those contexts where co-benefits or partial improvement outcomes of BMPs are more likely to be realized, as well as the impact of particular practices on specific ES.


2018 ◽  
Author(s):  
Romain Savary ◽  
Lucas Villard ◽  
Ian R. Sanders

AbstractArbuscular mycorrhizal fungi (AMF) have been shown to influence plant community structure and diversity. Studies based on single plant - single AMF isolate experiments show that within AMF species variation leads to large differential growth responses of different plant species. Because of these differential effects, genetic differences among isolates of an AMF species could potentially have strong effects on the structure of plant communities.We tested the hypothesis that within species variation in the AMF R. irregularis significantly affects plant community structure and plant co-existence. We took advantage of a recent genetic characterization of several isolates using double-digest restriction-site associated DNA sequencing (ddRADseq). This allowed us to test not only for the impact of within AMF species variation on plant community structure but also for the role of the R. irregularis phylogeny on plant community metrics. Nine isolates of R. irregularis, belonging to three different genetic groups (Gp1, Gp3 and Gp4), were used as either single inoculum or as mixed diversity inoculum. Plants in a mesocosm representing common species that naturally co-exist in European grasslands were inoculated with the different AMF treatments.We found that within-species differences in R. irregularis did not strongly influence the performance of individual plants or the structure of the overall plant community. However, the evenness of the plant community was affected by the phylogeny of the fungal isolates, where more closely-related AMF isolates were more likely to affect plant community evenness in a similar way compared to more genetically distant isolates.This study underlines the effect of within AMF species variability on plant community structure. While differential effects of the AMF isolates were not strong, a single AMF species had enough functional variability to change the equilibrium of a plant community in a way that is associated with the evolutionary history of the fungus.


Author(s):  
Maarten B. Eppinga ◽  
Elizabeth A. Haber ◽  
Luke Sweeney ◽  
Maria J. Santos ◽  
Max Rietkerk ◽  
...  

AbstractInvasions by non-native plant species are widely recognized as a major driver of biodiversity loss. Globally, (sub-)tropical islands form important components of biodiversity hotspots, while being particularly susceptible to invasions by plants in general and vines in particular. We studied the impact of the invasive vine A. leptopus on the diversity and structure of recipient plant communities on the northern Caribbean island St. Eustatius. We used a paired-plot design to study differences in species richness, evenness and community structure under A. leptopus-invaded and uninvaded conditions. Community structure was studied through species co-occurrence patterns. We found that in plots invaded by A. leptopus, species richness was 40–50% lower, and these plots also exhibited lower evenness. The magnitude of these negative impacts increased with increasing cover of A. leptopus. Invaded plots also showed higher degrees of homogeneity in species composition. Species co-occurrence patterns indicated that plant communities in uninvaded plots were characterized by segregation, whereas recipient plant communities in invaded plots exhibited random co-occurrence patterns. These observations suggest that invasion of A. leptopus is not only associated with reduced species richness and evenness of recipient communities in invaded sites, but also with a community disassembly process that may reduce diversity between sites. Given that A. leptopus is a successful invader of (sub-)tropical islands around the globe, these impacts on plant community structure highlight that this invasive species could be a particular conservation concern for these systems.


Author(s):  
Sikhululekile Ncube ◽  
Lindsay Beevers ◽  
Adebayo J. Adeloye ◽  
Annie Visser

Abstract. River systems provide a diverse range of ecosystem services, examples include: flood regulation (regulating), fish (provisioning), nutrient cycling (supporting) and recreation (cultural). Developing water resources through the construction of dams (hydropower or irrigation) can enhance the delivery of provisioning ecosystem services. However, these hydrologic alterations result in reductions in less tangible regulating, cultural and supporting ecosystem services. This study seeks to understand how multiple impoundments, abstractions and transfers within the upper Beas River Basin, Western Himalayas, India, are affecting the delivery of supporting ecosystem services. Whilst approaches for assessing supporting ecosystem services are under development, the immediate aim of this paper is to set out a framework for their quantification, using the macroinvertebrate index Lotic-Invertebrate Index for Flow Evaluation (LIFE). LIFE is a weighted measure of the flow velocity preferences of the macroinvertebrate community. Flow records from multiple gauging stations within the basin were used to investigate flow variability at seasonal, inter-annual and decadal time scales. The findings show that both mean monthly and seasonal cumulative flows have decreased over time in the Beas River Basin. A positive hydroecological relationship between LIFE and flow was also identified, indicative of macroinvertebrate response to seasonal changes in the flow regime. For example, high LIFE scores (7.7–9.3) in the winter and summer seasons indicate an abundance of macroinvertebrates with a preference for high flows; this represents a high potential for instream supporting ecosystem services delivery. However, further analysis is required to understand these hydroecological interactions in the study basin and the impact on instream supporting ecosystem services delivery.


2014 ◽  
Vol 41 ◽  
pp. 1-14 ◽  
Author(s):  
Fabienne Gralla ◽  
David J. Abson ◽  
Anders P. Møller ◽  
Daniel J. Lang ◽  
Henrik von Wehrden

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