News News

Random placement models can predict species–area relationships

Species–area relationships are the product of many ecological processes and their interactions. Explanations for the species–area relationship (SAR) have focused on separating putative niche-based mechanisms that correlate with area from sampling effects caused by patches with more individuals containing more species than patches with fewer individuals. The hypothesis that SARs in breeding waterfowl communities are caused by sampling effects was tested (i.e. random placement from the regional species pool). Consistent with the sampling effects hypothesis, observed SARs were accurately predicted by null models, which randomly allocated ducks to ponds, in three different years and for diving and dabbling duck guilds. This is the first demonstration that null models can predict SARs in waterbirds or any other aquatic organisms. Observed patterns of species association, however, were not well predicted by null models as in all years there was less observed segregation among species (i.e. more aggregation) than under the random expectation, suggesting that intraspecific competition could play a role in structuring duck communities. Taken together, results indicate that when emergent properties of ecological communities such as the SAR appear to be caused by random processes, analyses of species associations can be critical in revealing the importance of niche-based processes (e.g. competition) in structuring ecological communities. informacion[at] Bidwell et al (2014) Random placement models predict species–area relationships in duck communities despite species aggregation. Oikos DOI: 10.1111/oik.00821;jsessionid=6F2916A7C768D81F95C94CAA9594794D.f04t04
Average (0 Votes)

Latest News Latest News

Doñana's water quality, in danger due to intensive agriculture and a poor residual water treatment

? Un estudio llevado a cabo por la Estación Biológica de Doñana-CSIC advierte sobre el exceso de concentración de nutrientes en las aguas superficiales de Doñana, provocada por la actividad humana...

Large carnivore species recolonize Europe

Lobos, linces y osos pardos se encuentran entre las especies carnívoras más emblemáticas de Europa. En la última década, y después de rozar la extinción a finales del siglo pasado, están regresando...

Transporting Biodiversity Using Transmission Power Lines as Stepping-Stones

The most common ecological response to climate change is the shifts in species distribution ranges. Nevertheless, landscape fragmentation compromises the ability of limited dispersal species to...