%A Jie Han, Zehao Shen, Songlin Shi, Peihao Peng %T Comparison of plant species diversity and composition in the dry valleys of Yalong River and Dadu River: evaluating the effects of climate, topography and space %0 Journal Article %D 2016 %J Biodiv Sci %R 10.17520/biods.2015300 %P 421-430 %V 24 %N 4 %U {https://www.biodiversity-science.net/CN/abstract/article_8650.shtml} %8 2016-04-20 %X

The vegetation of dry valleys is a suit of unique azonal ecosystems embedded in the Hengduan Mountains region of Southwest China, with the difference of plant communities between the valleys and the causal factors still elusive. In this study, we investigated the dry valleys of the Yalong River and the Dadu River and compared plant diversity. Different factors were found to impact the vegetation types between the two rivers. Elevation and topography (slope and aspect) impacted vegetation types of the Yalong River and mean annual precipitation impacted the Dadu River. Plant richness in the valleys of the two rivers decreased with greater mean annual temperature. From a north to south aspect, plant richness of the dry valley communities decreased in the Yalong River, while increased in the Dadu River. Richness of shrubs in both the Yalong River and the Dadu River were greater at increased slopes. The β diversity of plant community in the dry valleys of the Yalong River and the Dadu River was affected more by environmental than geographical distance. The effect of geographical isolation on the two rivers was approximately 5 times greater than the effect of geographical distance. This research fills the knowledge gap about plant diversity of dry valleys vegetation in the Yalong River and the Dadu River, and reference information for vegetation conservation in the dry valleys of the two rivers. In addition, it provides a practical method for the quantitative assessment of geographical isolation effect on regional biodiversity difference.