Research Of Ecological Adaptation Of Annual Plant Synusia In Steppe And Desert Regions

It is a intent in the study that synthetically analyses ecologically adaptivemechanisms of annual plants tests, through researching seed bank and distributingstructure of annual plants, reproduceable strategy of annual plants,ecologicaldistributions and competition between annual plants and perennial plants,at onetime,analyzing the relationship between edaphic physico-chemical property andspecies constitution of annual plants,and so on four parts. In conclusion, it hasprimary conclusions as follows:1,Water is a key fator of affecting the distribution of annual plants.Species composition of annual plants turn into annual Chenopodiaceae from annualGramineae plants according to the flow of water from high to low.2,Soil seed bank of annual plants take on obvious horizontal and verticaldistribution pattern, and vertical distribution pattern shows that seeds mostlydistribute at 0～5 cm of soil surface, while horizontal distribution pattern shows thatthey take on obvious regional differences.3,There are obvious competitive relationships between annual and perennialplants in community. With increasing of perennial plants density, it affects thebiomass of plant, heigh of plant, relative growth rate, net primary production and competitive intensity of annual plants.4,The annual plants accumulating energy and using moisture have differentadaptive strategies from perennial plants. Annual plants adopt low heat value andhight water potential to adapt drought and competitive environment.5,Soil physical structure and nutrients both have remarkable influences onannual plants synusia. Available nitrogen and phosphorus of soil and other nutrientshave remarkable effects on biomass of annual synusia.