摘要
在围栏封育 4 a的 1 hm2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量较小 ,故在食物中的比例相应较小 ,为 31 % ;而在 7月份 ,则上升到 4 5% ,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 ,随着物候期的后移其利用率有较大幅度的下降 ,逐渐被糙隐子草所替代。禾草和冷蒿是放牧绵羊的主要食物资源 ,但冷蒿在夏季利用率较低。放牧绵羊有较强的食性选择 ,主要牧草的选择性采食顺序大致为 :乳白花黄芪、糙隐子草、扁蓿豆 >羊草、菊叶委陵菜和双齿葱 >冰草和冷蒿 >寸草苔、克代针茅和星毛委陵菜 ,即分为很喜食、喜食、随意采食和厌食 4个等级。不同季节食物替代明显 ,主要与食物的相对生物量、高度和频度显著相关 ;食物多样性指数较草地植物多样性指数高 ,且随放牧季节的向后推移呈下降趋势。
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
出处
《生态学报》
CAS
CSCD
北大核心
2000年第6期951-957,共7页
Acta Ecologica Sinica
基金
国家自然科学重大基金资助项目!( 39970 538)
中国科学院重大资助项目!( KZ951 -A1 -30 1 )
特别支持资助项目!( KT95T-0 4 -0 3)
关键词
内蒙古细毛羊
放牧季节
食性
草地状况
绵羊
Inner Mongolia fine wool sheep
grazing season
dietary compositix
