A comparison of the species–time relationship across ecosystems and taxonomic groups

Abstract

2006. A comparison of the species Á/time relationship across ecosystems and taxonomic groups. Á/ Oikos 112: 185 Á/195.The species Á/time relationship (STR) describes how the species richness of a community increases with the time span over which the community is observed. This pattern has numerous implications for both theory and conservation in much the same way as the species Á/area relationship (SAR). However, the STR has received much less attention and to date only a handful of papers have been published on the pattern. Here we gather together 984 community time-series, representing 15 study areas and nine taxonomic groups, and evaluate their STRs in order to assess the generality of the STR, its consistency across ecosystems and taxonomic groups, its functional form, and its relationship to local species richness. In general, STRs were surprisingly similar across major taxonomic groups and ecosystem types. STRs tended to be well fit by both power and logarithmic functions, and power function exponents typically ranged between 0.2 and 0.4. Communities with high richness tended to have lower STR exponents, suggesting that factors increasing richness may simultaneously decrease turnover in ecological systems. Our results suggest that the STR is as fundamental an ecological pattern as the SAR, and raise questions about the general processes underlying this pattern. They also highlight the dynamic nature of most species assemblages, and the need to incorporate time scale in both basic and applied research on species richness patterns.

The value of georeferenced collection records for predicting patterns of mosquito species richness and endemism in the Neotropics

“…Turner & Tj0rve, 2005;Drakare et al, 2006;White et al, 2006) but despite this complication, two thirds of the variation in mosquito species richness for countries in this study is explained by area. Foley et al (2007) showed a similar species-area relationship using worldwide country species data.…”

Temporal species turnover and plant community changes across different habitats in the Lake Engure Nature Park, Latvia

“…Species-time relationships (STR) were constructed using a sliding window approach (White et al, 2006;White and Gilchrist, 2007). Species richness was determined for every possible window of each time span: 12-year window, 11-year window, 10-year window etc.…”

“…This is because the power function suggests a constant percentage increase in species richness with each multiplicative increase in time scale, but the logarithmic function implies a constant absolute increase (see White et al, 2006 for detailed comparison of power and logarithmic function for STR).…”

“…It is documented that more diverse ecosystems are more stable in time (Shurin, 2007). It depends on environmental variability and ecosystem type, and in this respect, the importance of long-term spatially comprehensive data from a broad range of ecosystems has been stressed in recent publications (Adler, 2004;White et al, 2006;Magurran, 2007;Shurin, 2007;Magurran et al, 2010).…”

The many forms of beta diversity: a comment on McGill et al. and some notational suggestions

“…The main reason is probably the general lack of comparable, high quality, long term studies of biodiversity, which are needed to study spatial patterns in temporal species turnover. To be clear, I'm not proposing anything new here, and aspects of β t, − → s has been addressed in earlier studies (as I'm sure the authors of McGill et al are well aware), for instance in Russell et al [3] and White et al [4], and the type of data presented in Dornelas et al [5] could also be used to this end. To conclude, I fully support the call in McGill et al [1] for an increased focus on aspects of β-diversity, and hope that β t, − → s will be recognized more clearly in studies of biodiversity change, even if we currently have few empirical studies that address this issue, especially at larger spatial scales.…”