Study on respond of life-history strategies weeds and community structure of field to environmental factors in semiarid region

• 1、Key Laboratory of Arid and Grassland Ecology (Lanzhou University)
• 2、Key Laboratory of Arid and Grassland Ecology (Lanzhou University),

Abstract：From 2008 to 2009,we selected 10 native weeds and planted them in differentially treated cropland , to research the respond to environmental factors of the weed community structure in semiarid cropland, include the performance and respond to environmental factors of the 10 selected weed species. The results indicated: 1.The influence of weeds community structure by environment factors performed different levels :climate factors>the effect of planting weeds>ten effect of crop density. 2.The same species in different climate show different life-history strategies, Corisermum,Convolvulus arvensis and Fagopyrum dibotrys tended towards the competitor (C) strategy, stress tolerant (S) strategy and mixed competitor- stress tolerant (C-S) strategy in 2008,but stress tolerant (S) strategy, competitor -stress tolerant(CS strategy)and stress tolerant (S) strategy in 2009. 3.Chenpodium glaucum, Setaia viridis and Stipa breviflora tended towards the (R) strategy in 2008 ,but the (R)strategy haven’t showed life history strategies in 2009. Elsholzia argyi, Androsace ncana and Potentilla bifurc in the two years and Salsola in 2008 haven’t showed life-history strategies significance, Salsola tended towards the S- strategy in 2009. 4. With the variety of the ascendancy environment factors, life-history strategies according to change, that is, characteristics of life history respond to ecological attribute, so plant functionality have move in C-R-S axis of Grime model. Fagopyrum dibotrys tended towards a mixed stress tolerant- ruderal(S-R) strategy, Convolvulus arvensis tended towards a mixed competitor -stress tolerant(C-S) strategy in annual variety from 2008 to 2009.

Keywords： weeds life-history strategies crop interference community structure