家畜消化道传播影响荒漠草原种子更新潜力的机制研究

项目名称： 家畜消化道传播影响荒漠草原种子更新潜力的机制研究

项目编号： No.31501998

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 林学

项目作者： 任国华

作者单位： 山西农业大学

项目金额： 19万元

中文摘要： 促进放牧草地天然更新是实现草地植物多样性维持与可持续经营的重要途径。放牧家畜消化道传播是草地植物种子传播的重要途径之一，而关于消化道传播对种子更新潜力的影响机制目前还不清楚，这将对深刻认识放牧草地更新过程产生影响。本项目以山西雁门关生态畜牧区短花针茅荒漠草原和放牧家畜—绵羊为研究对象，通过野外放牧和室内定量饲喂种子，明确放牧家畜消化道传播种子的时空格局及群落常见组分种的消化道传播潜力；在种子性状多样性中筛选影响消化道传播过程，及之后随粪便排泄种子存活、萌发和幼苗生长的主要因子，揭示其直接和间接作用途径；并从种子持久性角度，基于种子的休眠释放和幼苗补充，阐明消化道作用前后持久种子库随时间的变化规律。通过以上研究，解析消化道传播对放牧草地种子更新潜力的影响机制。研究结果为深入理解草地植物多样性与草食动物放牧之间的关系、实现草原适应性管理与可持续经营提供重要理论参考。

中文关键词： 天然草地；退化；种子库；植被恢复；放牧

英文摘要： The natural renewal of grasslands is a vital process to maintain plant diversity and sustainable performance of the grazed ecosystems. The dispersal of seeds via livestock’s digestive system is one of the main dispersal vectors for many plant species. As yet, we have known little about the influence mechanism of endozoochorous seed dispersal by herbivores on seed regeneration potential of desert steppe. Therefore, in this study desert steppe of four different types are treated as an object of study in Yanmenguan Ecological and Animal Husbandry Economic Zone in Shanxi Province. Grazing is used to identify the spatial-temporal patterns of seed dispersal by investigating and quantifying the species composition and the number of the ingested seeds in sheep dung in grazed ecosystems. Meanwhile, the main stages after seed ingestion, namely seed recovery, seed germination, seedling emergence and early seedling establishment are studied by feeding known quantities of seeds of component species to four captive sheep. Besides, the project also further analyses the main ways that dispersal process and the survival of ingested seeds are affected by seed traits and compares the change of seed persistence between ingested and non-ingested seeds based on dormancy release and seedling complement during a period of time. The research results will be helpful for us to determine the impacts of endozoochorous seed dispersal by herbivores on seed regeneration potential of desert steppe, and will help understand the relationship between species diversity maintenance and herbivores grazing. The study will provide solution strategies for grassland adaptive management and sustainable operation of semi-arid grasslands.

英文关键词： natural grassland;degeneration;seed bank;vegetation recovery;grazing