喀斯特地区草地群落稳定性及其维持机制研究

The national projects such as "The comprehensive management of rocky desertification" have been carrying out in the Karst region like Guizhou province. Grassland restoration and construction has become one of the main measures that related to economic development and ecological environment protection, and grassland is the important ecological barrier in the upper reaches of Yangtze River and Pearl River. However, as to karst grassland community, whether be stable use for a long time, or the mechanism of its maintenance, has not been systematically studied, become the major task that urgent need solves in Karst areas..This study based on the rich natural grassland and 30 years of grassland construction practice in Guizhou, with the methods that first comprehensive using grassland agriculture, grassland ecology and molecular biology research, taking Guizhou typical natural grassland and permanent mixed pasture of leguminous and grasses. The research object, through the different combination and / or grassland under different utilization modes, is to investigate and analysis the primary productivity, composition, morphology and genetic diversity of dynamic community, on the levels of the system, community, population, individual and molecular, to found out the community stability and durability and maintenance mechanisms of Karst grassland, to guide rocky desertification comprehensive management practice with practical significance.

国家在贵州等喀斯特地区实施石漠化综合治理、岩溶草地治理等项目，草地恢复与建设成为经济发展与生态环境保护的主要措施，草地成为长江、珠江上游重要生态屏障。但是，岩溶草地群落能否稳定持久利用，其维持机制又如何一直没有得到系统研究，成为我国南方喀斯特地区草地建设迫切需要解决的重大课题。.本研究基于贵州丰富的天然草地和30多年的草地建设实践，首次综合采用草地农学、草地生态学和分子生物学等研究方法，以贵州典型天然草地和永久性豆科、禾本科牧草混播草地为研究对象，通过对不同组合和/或不同利用方式下草地群落初级生产力、群落组分、形态学特征以及遗传多样性的动态变化进行比较分析，从系统、群落、种群、个体和分子水平上研究和讨论喀斯特草地群落的稳定持久性及其维持机制，对石漠化综合治理实践具有实际意义。

人工草地长期稳定性及其机理研究，对石漠化治理以及草地畜牧业的可持续发展有重要的实践指导意义。本项目采用草地农学、草地生态学和分子生物学等学科的研究方法，从物种多样性与群落净生产力，群落组分构成与群落持久性，种间竞争与共存，利用制度与群落演替，牧草分子水平遗传多样性与种群持久性等方面研究草地群落长期稳定性的机理与机制。取得如下成果：.①混播草地各组分之间存在显著的生态位互补和竞争共存关系。.②永久性混播草地群落中，豆科牧草与禾草之间竞争不对等而实现竞争共存。.③草地不同利用制度、土地不同利用方式对群落组分影响显著。利用方式和交互作用对组分盖度有显著作用。放牧草地中的杂草密度高于刈割草地的杂草密度。放牧牛的草地杂草密度显著低于放牧绵羊的草地杂草密度。.④白三叶的形态学特征随利用年限的增加而进化，单株叶数、生长点数、中叶长、中叶长宽比以及种群内个体之间变异性随着年限的增加而增加。匍匐茎生物量随年限的增加而增加。.⑤贵州野生白三叶形态多样性丰富，同一花序及不同海拔高度的贵州野生白三叶形态都存在较大差异。.经过四年连续研究，取得了大量的野外、温室、实验室数据，由于研究紧密结合贵州草地建设实践，研究成果在贵州草地建设中有广阔的应用前景。