不同留茬高度对旱作混播草地群落特征和时间稳定性的影响OA

To investigate the effects of long-term annual mowing at different stubble heights on commu-nity characteristics and temporal stability in rainfed legume-grass mixed pasture,a mixed sward composed of Leymus chinensis,Medicago varia Martin.cv.Caoyuan No.2,and Bromus inermis was established as the experimental system.Five treatments were implemented:No mowing and stubble heights of 0,6,10,and 14 cm.Mowing was conducted annually in late August beginning in 2008,and by 2018 the pasture had undergone ten consecutive years of mowing,representing long term management.Community characteris-tics and temporal stability were analyzed for the period from 2018 to 2021.The results showed that long term annual mowing significantly increased the height of L.chinensis,the density of grasses(L.chinensis and B.inermis),the aboveground biomass of the community and individual forage species,and the commu-nity stability index(P<0.05).At a stubble height of 6 cm,the density of B.inermis and the community stability index were significantly higher than those under other stubble height treatments(P<0.05),and the aboveground biomass of M.varia was significantly higher than that under treatments with stubble heights of 10 cm,14 cm and no mowing(P<0.05).At a stubble height of 10 cm,the height of L.chinen-sis was significantly higher than that under other stubble height treatments(P<0.05),and the proportion of weed biomass was the lowest.Moreover,the interaction between stubble height and annual precipitation significantly enhanced community productivity and temporal stability(P<0.05).Overall,a stubble height of 6-10 cm is optimal to maintaining community productivity and temporal stability in rainfed legume-grass mixed pastures of Inner Mongolia under long term mowing management.