Recruitment of the high elevation cushion plant Arenaria polytrichoides is limited by competition,thus threatened by currently established vegetation  

作　　者：Jian-Guo Chen Yang Yang Song-Wei Wang Jurg Stocklin De-Li Peng Hang Sun 

机构地区：[1]Key Laboratory for Plant Diversity and Biogeography of East Asia,Kunming Institute of Botany,Chinese Academy of Sciences,Kunming 650201,China [2]School of life Sciences,Yunnan University,Kunming 650091,China [3]Botanical Institute,University of Basel,CH-4056 Basel,Switzerland [4]School of life Sciences,Yunnan Normal University,Kunming 650092,China

出　　处：《Journal of Systematics and Evolution》2020年第1期59-68,共10页植物分类学报（英文版）

基　　金：was supported equally by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA 20050203 to H.S.);the National Key R&D Program of China(2017YFC0505200 to H.S.);the National Natural Science Foundation of China(Major Program 31590823 to H.S.,31500185 to J.-G.C.);the Yunnan Applied Basic Research Project(2018FA015 to Y.Y.).The authors have no conflicts of interest to declare.

摘　　要：Cushion plants have been confirmed to be keystone species of alpine ecosystems. However, the adaptive strategies responsible for their recruitment and persistence remain largely unclear. Also, the effect of competition by species already established in surrounding vegetation is not known. We first assessed population size and the frequency distribution of individuals of different size in communities of the keystone cushion Arenaria polytrichoides Edgew. along an elevational gradient in southwestern China. Furthermore, in controlled experiments the effects of soil quality, light availability, and competition by other species on seedling recruitment and survival was tested. At lower elevation individuals were larger (elder), but population size (density) was lower compared to higher elevation;similarly, adults and old individuals were relatively more frequent at low elevation, whereas juvenile and small individuals were more frequent at higher elevations. Seedling recruitment differed depending on soil origin with seeds sown in soils from low elevation having a higher germination percentage and seedling survival when grown without competition. Competition by other species delayed germination but did not influence the final germination percentage, but it increased seedling mortality and reduced their survival. Full light accelerated the germination process, but did not affect final germination percentage and seedling mortality. Results suggest that the recruitment and persistence of A. polytrichoides is strongly affected by competition, whereas temperature and soil quality are less important. We speculate that when populations of cushion A. polytrichoides are likely to be exposed to higher competition due to environmental changes, this species is in danger of being weeded out.

关 键 词：Arenaria polytrichoides CUSHION species GERMINATION PERCENTAGE population persistence SEEDLING RECRUITMENT SEEDLING survival 

分 类 号：Q948[生物学—植物学]