scholarly journals Linking intrinsic scales of ecological processes to characteristic scales of biodiversity and functioning patterns

2021 ◽  
Author(s):  
Yuval R. Zelnik ◽  
Matthieu Barbier ◽  
David W. Shanafelt ◽  
Michel Loreau ◽  
Rachel M. Germain
Keyword(s):  
Species Interactions ◽  
Large Scale ◽  
Spatial Scales ◽  
Landscape Patterns ◽  
Ecological Processes ◽  
As Species ◽  
Species Area ◽  
Non Local ◽  
Systematic Understanding ◽  
Pattern Scale

Ecology is a science of scale, which guides our description of both ecological processes and patterns, but we lack a systematic understanding of how process scale and pattern scale are connected. Recent calls for a synthesis between population ecology, community ecology, and ecosystem ecology motivate the integration of phenomena at multiple levels of organization. Furthermore, many studies leave out the scaling of a critical process: species interactions, which may be non-local through mobility or vectors (resources or species) and must be distinguished from dispersal scales. Here, we use simulations to explore the consequences of different process scales (i.e. species interactions, dispersal, and the environment) on emergent patterns of biodiversity, ecosystem functioning, and their relationship, in a spatially-explicit landscape. A major result of our study is that the spatial scales of dispersal and species interactions have opposite effects: a larger dispersal scale homogenizes spatial biomass patterns, while a larger interaction scale amplifies their heterogeneity. We find that an interesting interplay between process scales occurs when the spatial distribution of species is heterogeneous at large scales, i.e., when the environment is not too uniform and dispersal not very strong. Interestingly, the specific scale at which scales of dispersal and interactions begin to influence landscape patterns depends on the environmental heterogeneity of the landscape -- in other words, the scale of one process allows important scales to emerge in other processes. Finally, contrary to our expectations, we observe that the spatial scale of ecological processes is more clearly reflected in landscape patterns (i.e. distribution of local outcomes) than in global patterns such as Species-Area Relationships or large-scale biodiversity-functioning relationships.

scholarly journals Contrasting effects of large density changes on relative testes size in fluctuating populations of sympatric vole species

2014 ◽  
Vol 281 (1792) ◽  
pp. 20141291 ◽  
Author(s):  
Ines Klemme ◽  
Carl D. Soulsbury ◽  
Heikki Henttonen
Keyword(s):  
Sperm Competition ◽  
Species Interactions ◽  
Large Scale ◽  
Density Fluctuations ◽  
Ecological Processes ◽  
Evolutionary Response ◽  
Density Relationship ◽  
Testes Size ◽  
Male Reproductive Effort ◽  
Fluctuating Populations

Across species, there is usually a positive relationship between sperm competition level and male reproductive effort on ejaculates, typically measured using relative testes size (RTS). Within populations, demographic and ecological processes may drastically alter the level of sperm competition and thus, potentially affect the evolution of testes size. Here, we use longitudinal records (across 38 years) from wild sympatric Fennoscandian populations of five species of voles to investigate whether RTS responds to natural fluctuations in population density, i.e. variation in sperm competition risk. We show that for some species RTS increases with density. However, our results also show that this relationship can be reversed in populations with large-scale between-year differences in density. Multiple mechanisms are suggested to explain the negative RTS–density relationship, including testes size response to density-dependent species interactions, an evolutionary response to sperm competition levels that is lagged when density fluctuations are over a certain threshold, or differing investment in pre- and post-copulatory competition at different densities. The results emphasize that our understanding of sperm competition in fluctuating environments is still very limited.

scholarly journals Species-area relationships emerge from multiple coexistence mechanisms

2021 ◽  
Author(s):  
David Garcia-Callejas ◽  
Ignasi Bartomeus ◽  
Oscar Godoy
Keyword(s):  
Species Richness ◽  
Spatial Heterogeneity ◽  
Species Interactions ◽  
Spatial Scales ◽  
Single Species ◽  
Small Population ◽  
Collective Effects ◽  
Demographic Stochasticity ◽  
Species Dominance ◽  
Species Area

The increase of species richness with area is a universal phenomenon on Earth. However, this observation contrasts with our poor understanding of how these species-area relationships (SARs) emerge from the collective effects of area, spatial heterogeneity, and local interactions. By combining a structuralist approach with five years of empirical observations in a highly-diverse grassland, we show that,contrary to expectations, spatial heterogeneity plays a little role in the accumulation of species richness with area in our system. Instead, as we increase the sampled area more species combinations are realized, and they coexist mainly due to direct pairwise interactions rather than by changes in single-species dominance or by indirect interactions. We also identify a small set of transient species with small population sizes that are consistently found across spatial scales. These findings empirically support the importance of the architecture of species interactions together with demographic stochasticity for driving SARs.

scholarly journals How sample heterogeneity can obscure the signal of microbial interactions

2019 ◽  
Author(s):  
David W. Armitage ◽  
Stuart E. Jones
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Species Interactions ◽  
Dynamic Models ◽  
Spatial Scales ◽  
Microbial Interactions ◽  
Vital Rates ◽  
Ecological Processes ◽  
Correlation Networks ◽  
Community Data

ABSTRACTMicrobial community data are commonly subjected to computational tools such as correlation networks, null models, and dynamic models, with the goal of identifying the ecological processes structuring microbial communities. Researchers applying these methods assume that the signs and magnitudes of species interactions and vital rates can be reliably parsed from observational data on species’ (relative) abundances. However, we contend that this assumption is violated when sample units contain any underlying spatial structure. Here, we show how three phenomena — Simpson’s paradox, context-dependence, and nonlinear averaging — can lead to erroneous conclusions about population parameters and species interactions when samples contain heterogeneous mixtures of populations or communities. At the root of this issue is the fundamental mismatch between the spatial scales of species interactions (micrometres) and those of typical microbial community samples (millimetres to centimetres). These issues can be overcome by measuring and accounting for spatial heterogeneity at very small scales, which will lead to more reliable inference of the ecological mechanisms structuring natural microbial communities.

scholarly journals Suburban frog ponds: mapping local land cover yields different estimates of landscape composition than the National Land Cover Database

2014 ◽  
Author(s):  
Max Lambert
Keyword(s):  
Land Cover ◽  
Large Scale ◽  
Forest Cover ◽  
Spatial Scales ◽  
Landscape Composition ◽  
Ecological Processes ◽  
Simple Method ◽  
Fine Grain ◽  
Land Cover Data ◽  
Ecological Patterns

Suburban neighborhoods are rapidly spreading globally. As such, there is an increasing need to study the environmental and ecological effects of suburbanization. At large spatial extents, from county-level to global, remote sensing-derived land cover data, such as the National Land Cover Dataset (NLCD), have yielded insight into patterns of urbanization and concomitant large-scale ecological patterns in response. However, the components of suburban land cover (houses, yards, etc.) are dispersed throughout the landscape at a finer scale than the relatively coarse grain size (30m pixels) of NLCD may be able to detect. Our understanding of ecological processes in heterogeneous landscapes is reliant upon the accuracy and resolution of our measurements as well as the scale at which we measure the landscape. Analyses of ecological processes along suburban gradients are restricted by the currently available data. As ecologists are becoming increasingly interested in describing phenomena at spatial extents as small as individual households, we need higher-resolution landscape measurements. Here, I describe a simple method of translating the components of suburban landscapes into finer-grain, local land cover (LLC) data in GIS. Using both LLC and NLCD, I compare the suburban matrix surrounding ponds occupied by two different frog species. I illustrate large discrepancies in Forest, Yard, and Developed land cover estimates between LLC and NLCD, leading to markedly different interpretations of suburban landscape composition. NLCD, relative to LLC, estimates lower proportions of forest cover and higher proportions of anthropogenic land covers in general. These two land cover datasets provide surprisingly different descriptions of the suburban landscapes, potentially affecting our understanding of how organisms respond to an increasingly suburban world. LLC provides a free and detailed fine-grain depiction of the components of suburban neighborhoods and will allow ecologists to better explore heterogeneous suburban landscapes at multiple spatial scales.

scholarly journals Global and regional ecological boundaries drive abrupt changes in avian frugivory interactions

2021 ◽  
Author(s):  
Lucas P Martins ◽  
Daniel B Stouffer ◽  
Pedro G Blendinger ◽  
Katrin Bohning-Gaese ◽  
Galo Buitron-Jurado ◽  
...  
Keyword(s):  
Network Structure ◽  
Human Disturbance ◽  
Species Interactions ◽  
Large Scale ◽  
Spatial Scales ◽  
Bird Species ◽  
Ecological Boundaries ◽  
Avian Frugivory ◽  
Abrupt Changes ◽  
Broad Spatial Scale

Species interactions can propagate disturbances across space, though ecological and biogeographic boundaries may limit this spread. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among ecological networks, while accounting for background spatial and elevational effects and differences in network sampling. We assessed network dissimilarity patterns over a broad spatial scale, using 196 quantitative avian frugivory networks (encompassing 1,496 plant and 1,003 bird species) distributed across 67 ecoregions and 11 biomes. Dissimilarity in species and interactions, but not in network structure, increased significantly across ecoregion and biome boundaries and along human disturbance gradients. Our findings suggest that ecological boundaries contribute to maintaining the world's biodiversity of interactions and mitigating the propagation of disturbances at large spatial scales.

Patterns of biological diversity

2019 ◽  
pp. 11-37
Author(s):  
Gary G. Mittelbach ◽  
Brian J. McGill
Keyword(s):  
Species Richness ◽  
Species Interactions ◽  
Biological Diversity ◽  
Spatial Scales ◽  
Species Numbers ◽  
Diversity Gradient ◽  
Species Abundances ◽  
Species Area ◽  
Species Area Relationship ◽  
The Relationship

This chapter examines how biodiversity, the variety of life, is distributed across the globe and within local communities. It begins by considering some of the challenges associated with assessing biological diversity at different spatial scales. Then, three of the best-studied patterns in species richness are examined in detail—the species–area relationship, the distribution of species abundances, and the relationship between productivity and species richness. The chapter concludes with a detailed exploration of the most dramatic of Earth’s biodiversity patterns—the latitudinal diversity gradient. The above patterns constitute much of what community ecology seeks to explain about nature. Their study provides a foundation from which to explore mechanisms of species interactions, and to understand the processes that drive variation in species numbers and their distribution.

scholarly journals Spatiotemporal patterns and ecological consequences of a fragmented landscape created by damming

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11416
Author(s):  
Guang Hu ◽  
Maxwell Wilson ◽  
Bing-Bing Zhou ◽  
Chenwei Shang ◽  
Mingjian Yu ◽  
...  
Keyword(s):  
Spatial Scales ◽  
River System ◽  
Terrestrial Ecosystems ◽  
Landscape Fragmentation ◽  
Spatiotemporal Analysis ◽  
Landscape Composition ◽  
Landscape Patterns ◽  
Fragmented Landscape ◽  
Ecological Processes ◽  
Future Studies

Background Damming disrupts rivers and destroys neighboring terrestrial ecosystems through inundation, resulting in profound and long-lasting impacts on biodiversity and ecosystem processes far beyond the river system itself. Archipelagos formed by damming are often considered ideal systems for studying habitat fragmentation. Methods Here we quantified the island attributes and landscape dynamics of the Thousand Island Lake (TIL) in China, which is one of the several long-term biodiversity/fragmentation research sites around the world. We also synthesized the major findings of relevant studies conducted in the region to further ecological understanding of damming and landscape fragmentation. Results Our results show that the vegetations on islands and the neighboring mainland were both recovering between 1985 and 2005 due to reforestation and natural succession, but the regeneration was partly interrupted after 2005 because of increasing human influences. While major changes in landscape composition occurred primarily in the lakefront areas and near-lakeshore islands, landscape patterns became structurally more complex and fragmented on both islands and mainland. About 80 studies from the TIL region show that the genetic, taxonomic, functional, and phylogenetic diversity on these islands were mainly influenced by island area at the patch scale, but fragmentation per se also affected species composition and related ecological processes at patch and landscape scales. In general, islands had lower species diversity but a steeper species-area relationship than the surrounding mainland. Fragmentation and edge effects substantially hindered ecological succession towards more densely vegetated forests on the islands. Environmental heterogeneity and filtering had a major impact on island biotic communities. We hypothesize that there are multiple mechanisms operating at different spatial scales that link landscape fragmentation and ecological dynamics in the TIL region, which beg for future studies. By focusing on an extensive spatiotemporal analysis of the island-mainland system and a synthesis of existing studies in the region, this study provides an important foundation and several promising directions for future studies.

scholarly journals The spatial configuration of biotic interactions shapes coexistence-area relationships in an annual plant community

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David García-Callejas ◽  
Ignasi Bartomeus ◽  
Oscar Godoy
Keyword(s):  
Species Richness ◽  
Spatial Heterogeneity ◽  
Species Interactions ◽  
Spatial Configuration ◽  
Spatial Scales ◽  
Single Species ◽  
Small Population ◽  
Collective Effects ◽  
Species Dominance ◽  
Species Area

AbstractThe increase of species richness with area is a universal phenomenon on Earth. However, this observation contrasts with our poor understanding of how these species-area relationships (SARs) emerge from the collective effects of area, spatial heterogeneity, and local interactions. By combining a structuralist approach with five years of empirical observations in a highly-diverse Mediterranean grassland, we show that spatial heterogeneity plays a little role in the accumulation of species richness with area in our system. Instead, as we increase the sampled area more species combinations are realized, and they coexist mainly due to direct pairwise interactions rather than by changes in single-species dominance or by indirect interactions. We also identify a small set of transient species with small population sizes that are consistently found across spatial scales. These findings empirically support the importance of the architecture of species interactions together with stochastic events for driving coexistence- and species-area relationships.

scholarly journals Reducing the Eltonian shortfall with trophic interaction models

2021 ◽  
Author(s):  
Dominique Caron ◽  
Luigi Maiorano ◽  
Wilfried Thuiller ◽  
Laura J. Pollock
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Functional Traits ◽  
Conservation Planning ◽  
Ecosystem Functioning ◽  
Species Interactions ◽  
Large Scale ◽  
Spatial Scales ◽  
Functional Trait ◽  
Predator Prey

While species interactions are fundamental for linking biodiversity to ecosystem functioning and for conservation, large-scale empirical data are lacking for most species and ecosystems. Accumulating evidence suggests that trophic interactions are predictable from available functional trait information, but we have yet to understand how well we can predict interactions across large spatial scales and food webs. Here, we built a model predicting predator-prey interactions based on functional traits for European vertebrates. We found that even models calibrated with very few known interactions (100 out of 71k) estimated the entire food web reasonably well. However, predators were easier to predict than prey, with prey in some clades being particularly difficult to predict (e.g., fowls and storks). Local food web connectance was also consistently over-estimated. Our results demonstrate the potential for filling gaps in sparse food webs, an important step towards a better description of biodiversity with strong implications for conservation planning.

scholarly journals Disturbance Effects on Spatial Autocorrelation in Biodiversity: An Overview and a Call for Study

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 167
Author(s):  
Shekhar R. Biswas ◽  
Jingyin Xiang ◽  
Hui Li
Keyword(s):  
Spatial Autocorrelation ◽  
Spatial Patterns ◽  
Species Interactions ◽  
Spatial Scales ◽  
Ecological Processes ◽  
Natural Systems ◽  
Restoration Planning ◽  
Habitat Disturbances ◽  
Disturbance Effects ◽  
Habitat Scale

The spatially autocorrelated patterns of biodiversity can be an important determinant of ecological processes, functions and delivery of services across spatial scales. Therefore, understanding disturbance effects on spatial autocorrelation in biodiversity is crucial for conservation and restoration planning but remains unclear. In a survey of disturbance versus spatial patterns of biodiversity literature from forests, grasslands and savannah ecosystems, we found that habitat disturbances generally reduce the spatial autocorrelation in species diversity on average by 15.5% and reduce its range (the distance up to which autocorrelation prevails) by 21.4%, in part, due to disturbance-driven changes in environmental conditions, dispersal, species interactions, or a combination of these processes. The observed effect of disturbance, however, varied markedly among the scale of disturbance (patch-scale versus habitat-scale). Surprisingly, few studies have examined disturbance effects on the spatial patterns of functional diversity, and the overall effect was non-significant. Despite major knowledge gaps in certain areas, our analysis offers a much-needed initial insights into the disturbance-driven changes in the spatial patterns of biodiversity, thereby setting the ground for informed discussion on conservation and promotion of spatial heterogeneity in managing natural systems under a changing world.

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