干旱区生态环境知识资源中心

Glycyrrhiza uralensis is an endangered and nationally-protected medicinal plant species in China with great market demand. It is mainly distributed in arid and semi-arid regions and its habitats have rapidly degraded over the last 40 years. Conservation of this species and its communities has become urgent. We aimed to reveal the relationships between G. uralensis and environmental variables along an east to west precipitation gradient in northern China. Floristic and environmental data from 100 5 m x 5 m quadrats were analyzed using TWINSPAN, DCA, CCA and species diversity indices. TWINSPAN recognized twelve vegetation communities, which were the communities most dominated by G. uralensis in China. DCA and CCA results showed that the vegetation patterns were significantly correlated with both soil and climatic variables. Soil N, P, K, organic matter, annual mean temperature, relative humidity, annual mean precipitation, annual mean highest temperature and annual mean lowest temperature were significant to these communities, and precipitation was the most important factor explaining the spatial patterns of vegetation. Species richness, diversity and evenness varied obviously among communities and were significantly correlated with environmental gradients. Further measures for conservation of G. uralensis and its communities are discussed.