Positive effects of shrubs on herbaceous species richness across several spatial scales: evidence from the semiarid Andean subtropics.

摘要: Question: What is the effect of shrubs on herbaceous species richness at three spatial scales: quadrat, site, and region? Location: Prepuna, subtropical semi-arid Andes. Methods: At eight sites, we recorded presence in spaces beneath shrubs/small trees open areas. quadrat scale, average number per was calculated compared between two microhabitats (shrubs/open). local (site) all quadrats each site were pooled according to microhabitat, sites then combined for regional analysis. Results conclusions: We found greater below scales considered. Several exclusively associated with shrub undercanopy. This seems depend more inventory diversity different than differentiation communities shrubs. Facilitation be responsible increase shrubs, but further experimental study needed obtain insight into underlying mechanisms.