Dataset Information

Plant species-area relationships are determined by evenness, cover and aggregation in drylands worldwide.

ABSTRACT:

Aim

Species-area relationships (also known as 'species-area curves' and 'species accumulation curves') represent the relationship between species richness and the area sampled in a given community. These relationships can be used to describe diversity patterns while accounting for the well-known scale-dependence of species richness. Despite their value, their functional form and parameters, as well as their determinants, have barely been investigated in drylands.

Location

171 drylands from all continents except Antarctica.

Time period

2006-2013.

Major taxa studied

Perennial plants.

Methods

We characterized species-area relationships of plant communities by building accumulation curves describing the expected number of species as a function of the number of sampling units, and later compared the fit of three functions (power-law, logarithmic and Michaelis-Menten). We tested the prediction that the effects of aridity, soil pH on SAR are mediated by vegetation attributes such as evenness, cover, and spatial aggregation.

Results

We found that the logarithmic relationship was the most common functional form (c.50%), followed by Michaelis-Menten (c.33%) and power-law (c.17%). Functional form was mainly determined by evenness. Power-law relationships were found mostly under low evenness, logarithmic relationships peaked under intermediate evenness and the Michalis-Menten function increased in frequency with increasing evenness. The SAR parameters approximated by the logarithmic model ('small-scale richness' (b₀ ) and 'accumulation coefficient' (b₁ )) were determined by vegetation attributes. Increasing spatial aggregation had a negative effect on the small-scale richness and a positive effect on the accumulation coefficient, while evenness had an opposite effect. In addition, accumulation coefficient was positively affected by cover. Interestingly, aridity decreased small scale richness but did not affect the accumulation coefficient.

Main conclusions

Our findings highlight the role of evenness, spatial aggregation and cover as main drivers of species area relationships in drylands, the Earth's largest biome.

SUBMITTER: DeMalach N

PROVIDER: S-EPMC6420124 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Publications

Plant species-area relationships are determined by evenness, cover and aggregation in drylands worldwide.

DeMalach Niv N Saiz Hugo H Zaady Eli E Maestre Fernando T FT

Global ecology and biogeography : a journal of macroecology 20181211 3

<h4>Aim</h4>Species-area relationships (also known as 'species-area curves' and 'species accumulation curves') represent the relationship between species richness and the area sampled in a given community. These relationships can be used to describe diversity patterns while accounting for the well-known scale-dependence of species richness. Despite their value, their functional form and parameters, as well as their determinants, have barely been investigated in drylands.<h4>Location</h4>171 dryl ...[more]

PMID: 30886537

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Dataset Information

Plant species-area relationships are determined by evenness, cover and aggregation in drylands worldwide.

Aim

Location

Time period

Major taxa studied

Methods

Results

Main conclusions

Publications

Plant species-area relationships are determined by evenness, cover and aggregation in drylands worldwide.

Similar Datasets

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