Hydrophytes of the oases in the Sierra de la Giganta of Central Baja California Sur, Mexico: Floristic composition and conservation status [An article from: Journal of Arid Environments]

This digital document is a journal article from Journal of Arid Environments, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
One of the features of the Sierra de la Giganta mountain range is the existence of many small riparian wetlands (oases) along drainage channels. There are no geohydrological studies from which to determine their dynamics in the arid environment, but these areas confront increasing water extraction to satisfy demands of small local settlements. This study compiled a checklist of the hydrophytes from 12 representative oases, and discusses their current status on the basis of composition, richness, and species characteristics. Floristic composition (absence-presence of 57 hydrophytes) at each location was classified by using UPGMA to represent a dendrogram of group cohesivity. Two major kinds of locations are present. By analysing individual site characteristics, we found that one group occurs in places under ''good conservation conditions'' and the other composed of locations that are ''impacted'' in several ways. The former group contains oases that are relatively rich in species, including most of the aquatic forms, which are sensitive to disturbance. Geographical affinity of the floristic list reveals that most species have a broad distribution, mostly in tropical America.