Species Diversity and Genetic Diversity: Parallel Processes and Correlated Patterns

Abstract

Species diversity and genetic diversity may be correlated as a result of processes acting in parallel at the two levels. However, no theories predict the conditions under which different relationships between species diversity and genetic diversity might arise and therefore when one level of diversity may be predicted using the other. I used simulation models to investigate the parallel influence of locality area, immigration rate, and environmental heterogeneity on species diversity and genetic diversity. The most common pattern was moderate to strong positive species-genetic diversity correlations (SGDCs). Such correlations may be driven by any one of the three locality characteristics examined, but important exceptions and patterns emerged. Genetic diversity and species diversity were more weakly correlated when genetic diversity was measured for rare versus common species. Environmental heterogeneity not only imposes spatially varying selection on populations and communities but also causes changes in species' population sizes and therefore genetic diversity; these interacting processes can create positive, negative, or unimodal relationships of genetic diversity with species diversity. When species are considered as part of multispecies communities, predictions from single-species models of genetic diversity apply in some instances (effects of area and immigration) but often not in others (effects of environmental heterogeneity).

The Maintenance of Genetic Variation Due to Asymmetric Gene Flow in Dendritic Metapopulations

“…While the mechanisms leading to the maintenance of genetic variation are different from those that maintain species diversity (although see Velland 2005), expected patterns of genetic diversity are similar to patterns in other ecological properties of dendritic systems. Higher species diversity is generally found in networks with higher numbers of nodes and branches (Campbell Grant et al 2007).…”

Fighting carbon loss of degraded peatlands by jump-starting ecosystem functioning with ecological restoration

“…However, more heterogeneous communities are more likely to be able to adapt to the changing environments of the future (see e.g. Vellend 2005Vellend , 2010. Therefore, some increased heterogeneity in communities may in fact be desirable from the perspective of adaption of communities in changing environmental conditions (Harris et al 2006, Jackson and).…”

“…This is because more heterogeneous communities are more likely to be able to adapt to the changing environments of the future (see e.g. Vellend 2005Vellend , 2010. If the target is the original or pristine community composition, then restoration needs to overcome the resistance and resilience of the degraded system, and to strengthen the resistance and resilience of the recovered system in order to facilitate its long term persistency.…”

Genetic structure of a foundation species: scaling community phenotypes from the individual to the region

“…Because each of these plant traits influence dependent community members, a genetic basis to these scaling relationships across individuals may scale up to higher levels by having consequences for the dependent community structure and species richness. However, few studies have attempted to connect the genetic-based patterns at the individual level with biodiversity patterns (but see Vellend, 2005; but see case II of Vellend and Geber, 2005;Shuster et al, 2006), especially at larger spatial scales. Future studies must bridge this gap if we are to realize the potential of genetic scaling to explain many important ecological, evolutionary, and biodiversity patterns.…”