Effects of Different Management Regimes on Restoration of the Degraded Stipa Grandis Typical Steppe Community in Xilingol

27 Mar Effects of Different Management Regimes on Restoration of the Degraded Stipa Grandis Typical Steppe Community in Xilingol

View Original

Abstract

在内蒙古锡林郭勒典型草原区 选 取 有 代 表 性 的 退 化 大 针 茅—糙隐子草群落，设 置 三 种 不 同 的 管 理 方 式， 即放牧不刈割、无牧无刈割围封禁牧、无牧一 次 刈 割 围 封 禁 牧。经过８ 年 不 同 的 管 理 后，采 用 样 方 法 对 群 落 物 种 组 成、植物高度、地上生物量进行实地调查，并计算群落物种多样性、丰富度和均匀度；同时，测定群落内主要植物种的 净光合速率、叶片 Ｎ 含量、比叶面积等功能性状。结果表明：（１）与放牧不刈割管理相比，在两种围封禁牧管理下，群 落单位面积的生物量以及多年生禾草占总地上部生物量的比例均增加，群落的 Ｍａｒｇａｌｅｆ丰富度指数提高，群落内主 要物种的水分利用效率显著提高，群 落 优 势 种 由 糙 隐 子 草 过 渡 为 大 针 茅，已 具 有 明 显 的 典 型 草 原 特 征；但群落的 Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ多样性指数无显著差异，群落内主要物种的净光合速率、叶片 Ｎ 含量和比叶面积等功能性状无一致 变化趋势，植株高度也无显著差异。（２）无牧一次刈割管理方式下的群落内物种数高于另外两种管理方式。综上所 述，对于内蒙古锡林郭勒的大针茅退化草原来讲，实施无牧一次刈割围封禁牧管理有利于退化群落的恢复。

English Abstract

Three management regimes were devised in the typical degraded Stipa grandis鈥擟leistogenes squarrosa steppe community in Xilingol,Inner Mongolia,namely grazing but non-mowing,neither grazing nor mowing and non-grazing but an mowing.After eight years’ different management regimes,species composition,plant height and above-ground biomass were investigated with quadrat method.Then,species diversity,richness,and evenness were calculated.Functional traits of the main species in communities,including net photosynthetic rate,leaf nitrogen content,specific leaf area(SLA),were measured simultaneously.(1) Compared with the variables under the grazing but non-mowing management regime,communities’ biomass per unit area,the Margalef richness index,the proportion of perennial grasses’ above-ground biomass and the major species water use efficiency were higher under the two enclosure management regimes,and the dominant species of the communities were transited from Cleistogenes squarrosa to Stipa grandis,which showed the characteristics of the typical steppe;however,the communities’ Shannon-Wiener index had no significant difference,and the functional traits of major species,including net photosynthetic rate,leaf nitrogen content and SLA had no consistent trends;besides,the height of plants had no significant difference.(2) Under the non-grazing but an mowing management regime,the number of species in the community was higher than that under the other two management regimes.In conclusion,as for the degraded Stipa grandis typical steppe in Xilingol,Inner Mongolia,the non-grazing but an mowing management regime benefited not only the restoration of the degraded communities,but also the herdsmen’s economic income.