Relationship Between Soil Moisture and Patch Characteristics of Melica przewalskyi i Communities in a Degraded Alpine Grassland in Gansu, China

Abstract

Vegetation usually adapts to and also affects the soil moisture of the stand where it lives.In the upstream area of Shiyang River,Gansu Province,China,alpine degraded grasslands are dominated by Melica przewalskyii.The vegetation patch characteristics,soil moistures and their relationships were studied.The results showed that: The height,density and cover of the species were decreased from center of the patches to the edges at formation,diffusion and stable periods of the community succession.But at recession period,the trend was reversed,with higher soil moisture in center and within the vegetation patches.Along the vegetation succession,the relationship between soil moisture and the vegetation parameters changed from negatively correlated to positively correlated.It was suggested that M.przewalskyii was highly adaptive as it could modify the fine-scale soil moisture distribution pattern to create a favorable condition for its population establishment and development in arid environment.Tab 3,Ref 16