不同放牧季节绵羊的食性及食物多样性与草地植物多样性间的关系

在围栏封育４ａ的１ｍｈ＾２放牧样地内，放牧４只内蒙古细毛羊，分别于６、７和９月份用显微技术法进行了绵羊食性的研究。结果表明，在放牧率较低食物资源比较丰富的条件下，绵羊的食性表现为明显的季节性变化。６月份，由于禾草在群落中的相对生物最较小，故在食物中的比例相应较小，为３１％；而在７月份，则上升到４５％，部分替代了冷蒿在食物中的比例；同时，在禾草中，羊草、冰草主要在春季或初夏（７月份以前）被利用，随着

The dietary composition of fine wool sheep and plant diversity in Inner Mongolia steppe

The experiment was conducted at Inner Mongolia steppe The results showed that the dietary composition of sheep had significant change with grazing seasons from June to September The proportion of grasses was the maximum in July and Leymus chinensis, and Agropypron cristatum were main ingested by sheep before July.Intake of Artemisia frigida was lower in July than in June and September The sheep avoided to graze Potentilla acaulis and Carex duriuscula The order of preferred plant species can be divided into 4 strategies: Astragalus galactites,Cleistogenes squarrosa and Melissitus ruthenica > Leymus chinensis,Potentilla tanacetifolia and Allium bidentatum > Agropyron cristatum and Artemisia frigida > Carex duriuscula,Stipa krylovii and Potentilla acaulis Meanwhile,the dietary composition depended on relative biomass,height and frequency of different plant species The diversity index in dietary composition was higher than in rangeland community and decreased with grazing season backward