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.

Hot-Spot Facts and Artifacts-Questioning Israel's Great Biodiversity

2009 ◽  
Vol 55 (3) ◽  
pp. 263-279 ◽  
Author(s):  
Uri Roll ◽  
Lewi Stone ◽  
Shai Meiri
Keyword(s):  
Species Richness ◽  
Biological Diversity ◽  
Hot Spot ◽  
Flowering Plants ◽  
Prediction Intervals ◽  
Predicting Factors ◽  
Mediterranean Countries ◽  
Species Area ◽  
Expected Values ◽  
Species Area Relationship

Israel's biological diversity has been praised as being particularly rich in relation to its size; however this assumption was never tested when taking into account the empirical form of the species-area relationship. Here we compared the species richness of different countries to see if the Israeli diversity is exceptionally rich when area is accurately accounted for. We compared richness of amphibians, birds, mammals, reptiles, flowering plants, conifers and cycads, and ferns in all the world's countries. We further tested the effects of mean latitude, altitude span, and insularity on species richness both for all world countries and just for Mediterranean countries. For all taxa and in all tests, Israel lies within the prediction intervals of the models. Out of 42 tests, Israel's residuals lie in the upper decile of positive residuals once: for reptiles, when compared to all world countries, taking all predicting factors into account. Using only countries larger than 1000 km2, Israel was placed as top residual when compared to other Mediterranean countries for mammals and reptiles. We therefore conclude that Israel's species richness does not significantly exceed the expected values for a country its size. This is true when comparing it to either world or just Mediterranean countries. Adding more predicting factors does not change this fact.

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 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 The strength of the biodiversity–ecosystem function relationship depends on spatial scale

2018 ◽  
Vol 285 (1880) ◽  
pp. 20180038 ◽  
Author(s):  
Patrick L. Thompson ◽  
Forest Isbell ◽  
Michel Loreau ◽  
Mary I. O'Connor ◽  
Andrew Gonzalez
Keyword(s):  
Spatial Variation ◽  
Spatial Scale ◽  
Spatial Scales ◽  
Scale Dependence ◽  
Α Diversity ◽  
Species Area ◽  
Species Area Relationship ◽  
Function Relationship ◽  
New Research ◽  
The Relationship

Our understanding of the relationship between biodiversity and ecosystem functioning (BEF) applies mainly to fine spatial scales. New research is required if we are to extend this knowledge to broader spatial scales that are relevant for conservation decisions. Here, we use simulations to examine conditions that generate scale dependence of the BEF relationship. We study scale by assessing how the BEF relationship (slope and R 2 ) changes when habitat patches are spatially aggregated. We find three ways for the BEF relationship to be scale-dependent: (i) variation among local patches in local (α) diversity, (ii) spatial variation in the local BEF relationship and (iii) incomplete compositional turnover in species composition among patches. The first two cause the slope of the BEF relationship to increase moderately with spatial scale, reflecting nonlinear averaging of spatial variation in diversity or the BEF relationship. The third mechanism results in much stronger scale dependence, with the BEF relationship increasing in the rising portion of the species area relationship, but then decreasing as it saturates. An analysis of data from the Cedar Creek grassland BEF experiment revealed a positive but saturating slope of the relationship with scale. Overall, our findings suggest that the BEF relationship is likely to be scale dependent.

Organisation de la richesse et de la composition floristiques d'îles de la Méditerranée occidentale (sud-est de la France)

1998 ◽  
Vol 76 (2) ◽  
pp. 321-331 ◽  
Author(s):  
Frédéric Médail ◽  
Éric Vidal
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Species ◽  
Habitat Diversity ◽  
Mediterranean Islands ◽  
Plant Dispersal ◽  
Number Of Species ◽  
Continental Islands ◽  
Species Area ◽  
Species Area Relationship

The effects of physiographic variables (area, isolation, elevation, and substrate) and habitat diversity on plant species richness and composition have been investigated on some Mediterranean islands (southeastern France). The number of species - area relationship is significant but there are more diverse vegetation patterns on smallest islands (area smaller than 3.5 ha and, ultimately, 0.2 ha). Although the species composition is positively correlated to the distance from the continent, the effect of isolation is not so obvious because of the small distance of these continental islands from the continent. Some islands nearest to shore show very different plant species composition, suggesting a nonselective plant dispersal through some narrow stretches of sea. Habitat diversity represents one of the major explanatory factors of the species richness; nevertheless, it is not possible to settle between the two hypotheses effect of habitat diversity versus effect of area per se because of the correlation between the two factors. Key words: Mediterranean islands, insular biogeography, number of species - area relationship, isolation, habitat diversity, islets.

scholarly journals Wood ant assemblages of Formica rufa group on lake islands and in mainland woodland in Central Finland

2018 ◽  
Vol 29 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Jouni Sorvari
Keyword(s):  
Species Richness ◽  
Occurrence Probability ◽  
Island Size ◽  
Formica Rufa ◽  
Wood Ants ◽  
Formica Rufa Group ◽  
Species Area ◽  
Island Community ◽  
Species Area Relationship ◽  
Formica Lugubris

Associations of island size and isolation on the occurrence and species richness of five wood ant species of the Formica rufa group (F. rufa, F. aquilonia, F. lugubris, F. polyctena and F. pratensis) was tested in the Lake Konnevesi archipelago in Central Finland. In addition, the species composition was compared to that of mainland forests of the same region. Island isolation had no associations with the wood ant occurrence in this archipelago, but for most species, increasing island size was positively associated with the occurrence probability. According to the findings among the five species, Formica lugubris is the best adapted for insular living. There was a positive species–area relationship as the species richness of wood ants increased with an increasing island size. The island community of wood ants was dominated by colonies of the monogynous (single queen) species whereas the mainland community was dominated by those of polygynous (multiple queen) species.

scholarly journals Species-area and network-area relationships in host–helminth interactions

2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Tad A. Dallas ◽  
Pedro Jordano
Keyword(s):  
Species Richness ◽  
Trophic Interactions ◽  
Species Interactions ◽  
Geographical Area ◽  
Species Interaction ◽  
Helminth Parasites ◽  
Scaling Relationship ◽  
Theoretical Predictions ◽  
Species Area ◽  
Network Area

The scaling relationship observed between species richness and the geographical area sampled (i.e. the species-area relationship (SAR)) is a widely recognized macroecological relationship. Recently, this theory has been extended to trophic interactions, suggesting that geographical area may influence the structure of species interaction networks (i.e. network-area relationships (NARs)). Here, we use a global dataset of host–helminth parasite interactions to test existing predictions from macroecological theory. Scaling between single locations to the global host–helminth network by sequentially adding networks together, we find support that geographical area influences species richness and the number of species interactions in host–helminth networks. However, species-area slopes were larger for host species relative to their helminth parasites, counter to theoretical predictions. Lastly, host–helminth network modularity—capturing the tendency of the network to form into separate subcommunities—decreased with increasing area, also counter to theoretical predictions. Reconciling this disconnect between existing theory and observed SAR and NAR will provide insight into the spatial structuring of ecological networks, and help to refine theory to highlight the effects of network type, species distributional overlap, and the specificity of trophic interactions on NARs.

scholarly journals A universal scaling method for biodiversity-ecosystem functioning relationships

2019 ◽  
Author(s):  
K.E. Barry ◽  
G.A. Pinter ◽  
J.W. Strini ◽  
K. Yang ◽  
I.G. Lauko ◽  
...  
Keyword(s):  
Species Richness ◽  
Biomass Production ◽  
Ecosystem Functioning ◽  
Spatial Scales ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Additional Species ◽  
Spatial And Temporal Scales ◽  
Natural Systems ◽  
Species Area

SummaryGlobal biodiversity is declining at rates faster than at any other point in human history. Experimental manipulations of biodiversity at small spatial scales have demonstrated that communities with fewer species consistently produce less biomass than higher diversity communities. However, understanding how the global extinction crisis is likely to impact global ecosystem functioning will require applying these local and largely experimental findings to natural systems at substantially larger spatial and temporal scales. Here we propose that we can use two simple macroecological patterns – the species area curve and the biomass-area curve – to upscale the species richness-biomass relationship. We demonstrate that at local spatial scales, each additional species will contribute more to biomass production with increasing area sampled because the species-area curve saturates and the biomass-area curve increases monotonically. We use species-area and biomass-area curves from a Minnesota grassland and a Panamanian tropical dry forest to examine the species richness – biomass relationship at three and ten sampling extents, respectively. In both datasets, the observed relationship between biodiversity and biomass production at every sampling extent was predicted from simple species-area and biomass-area relationships. These findings suggest that macroecological patterns like the species-area curve underpin the scaling of biodiversity-ecosystem functioning research and can be used to predict these relationships at the global scales where they are relevant for species loss.

Spatial Scale and Biodiversity

Ecology ◽  
2019 ◽  
Author(s):  
Daniel J. McGlinn ◽  
Michael W. Palmer
Keyword(s):  
Spatial Scale ◽  
Species Interactions ◽  
Mass Extinction ◽  
Indelible Mark ◽  
Coexistence Theory ◽  
The World ◽  
Species Area ◽  
Increase Productivity ◽  
Species Area Relationship ◽  
Empirical Tests

The scale of observation leaves an indelible mark on our understanding of biodiversity. Despite wide recognition among ecologists that scale is important, most theories of biodiversity and coexistence treat mechanisms as scale-independent (e.g., coexistence theory). Furthermore, most empirical tests of theory are still only performed at a single spatial scale. A fuller understanding of scale is likely to help resolve some of ecology’s ongoing controversies. Does biodiversity increase productivity? Is the world experiencing the sixth major mass extinction? Are species interactions relevant to understanding biodiversity? Does exotic biodiversity decrease native biodiversity? We know the answers to these questions depend in large part on scale. However simply recognizing that scale plays a role is not sufficient, and currently several bodies of theory are emerging that provide a vision of a more unified ecology in which scale plays a central role. Ultimately, the daunting problems facing biodiversity require that we consider scale directly in our hypotheses. The goal of this bibliography is to highlight key papers that define scale and discuss how it influences biodiversity patterns. Another Oxford Bibliographies in Ecology article, “Species-Area Relationships” by Samantha M. Tessel, Kyle A. Palmquist, and Robert K. Peet is devoted entirely to the species-area relationship and therefore that topic is covered in less depth here.

scholarly journals The species-area relationship: new challenges for an old pattern

2001 ◽  
Vol 25 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Mark V. Lomolino
Keyword(s):  
Secondary Phase ◽  
Species Number ◽  
General Tendency ◽  
Small Islands ◽  
Stochastic Variation ◽  
Causal Explanations ◽  
Island Area ◽  
Species Area ◽  
Species Area Relationship ◽  
The Relationship

The species-area relationship (i.e., the relationship between area and the number of species found in that area) is one of longest and most frequently studied patterns in nature. Yet there remain some important and interesting questions on the nature of this relationship, its causality, quantification and application for both ecologists and conservation biologists. Traditionally, the species-area relationship describes the very general tendency for species number to increase with island area; a relationship whose slope declines (but remains positive) as area increases. The true relationship, however, may be much more complicated than this, and may in many cases approximate a sigmoidal relationship. On small islands, species number may vary independently of island area. Species richness then increases as we consider larger islands, but the curve eventually slows and asymptotes or levels off when richness equals that of the the source or mainland pool. The relationship may also include a secondary phase of increase in richness if island area becomes large enough to allow in situ speciation. Causal explanations for this relationship may, therefore, need to be multifactorial and include a range of processes from disturbance and stochastic variation in habitat quality on the very small islands, to ecological interactions, immigration, extinction and, finally, evolution on the larger islands.

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