Facilitation Of Cushion Plant On Soil Enzyme Activities In Alpine Areas

Alpine ecosystem is one of most important ecosystem types in the world.Its climatic characteristic is low temperature,high radiation,strong wind and so on.Cushion plants are a common growth form in alpine areas.Because of their low stature,and compact form,cushion plants can facilitate recruitment of other plant species in alpine areas.The facilitation of cushion plants has been extensively studied.However,few studies have simultaneously explored the positive interaction of several cushion pants in several alpine regions.Little is known about the effect of soil enzyme activity under cushion plants.In our experiment,we used seven cushion species in 10 different alpine areas of western China,which are spanned three climatic zones.We analysed the influence of cushion plants on soil enzyme activity and explored the correlation between soil enzyme activity and soil fertility properties.The results indicate that:1)Soil enzyme activities were significantly different in ten different places.The activities of urease,invertase and protease in soil of Yunnan Baima are the highest,and in soil of Qinghai Reshui and Qinghai Datong the lowest.The reason was that temperature,soil water content and nutrient were higher in Yunnan Baima,but soil water content and nutrient was lower in Qinghai Reshui and Qinghai Datong.2)The effects of cushion plants on soil enzyme were various in different places.The facilitation effect of Rhododendron nivale and Arenaria kansuensis on soil enzyme activities increased with environmental stress,but the facilitation effect of Thylacospermum caespitosum and Arenaria polytrichoides on soil enzyme activities decreased with environmental stress.3)The influences of different cushion plants on soil enzyme were different.Compared with open areas,soil invertase activity beneath Rhodiola dumulosa and Sibbaldia tetrandra was all increased,while soil invertase activity was decreased under Cassiope fastigiata.4)There was significant correlations beween soil enzyme activities and soil fertility.There was a positive relation between soil urease and soil fertility,but the correlation between the activities of invertase,protease,neutral phosphatase and soil fertility was impacted by cushion plants.In general,soil enzyme activities were influenced by vegetation species and regions.There was significant correlation between soil enzyme activities and soil fertility.Soil nutrients are important in stimulating microbial activity,suggesting that cushion plants effects on soil enzyme activity were driven primarily by soil nutrients.Final,cushion plants may offer a more favorable habitat for seed germination and seedling recruitment than the bare ground.This work shows a new framework to investigate the interplay of facilitation.Then,it will provide important direction for the maintenance of alpine biodiversity.