Long-Term Ecological Effects of Sheep Grazing in Alpine Ecosystems and its Integration with Management, 2011

We propose to further develop two unique experimental studies in contrasting alpine ecosystems (running from 2000 in Setesdal Vesthei and 2002 in Hol) to address several important new research questions: The overall aim is to facilitate sustainable management of sheep grazing in alpine habitats by providing a scientific basis for relating management alternatives (sheep density) to specific long-term ecological effects of grazing. The initial 6-8 yrs of these two sheep grazing experiments revealed that short-term effects differ for plants, invertebrates, rodents and birds. In addition, effects depend on factors like sheep density and habitat productivity. However, these short-term impacts may differ from long-term ones, because many effects are likely to be indirect, mediated through plants and processes in the soil. Specific objectives are to perform the first experimental, long-term (10 year) study of sheep grazing effects in two contrasting ecosystems (rich and poor), to assess (1) long-term and cascading ecosystem effects; (2) tree-line dynamics along a taiga-tundra ecotone and (3) soil physical and biogeochemical processes and properties; (4) to link density dependent sheep grazing ecology and life history to long-term plant development to understand better how climate and density affect ungulate life history at different temporal scales, and (5) to integrate data from ecological experiments with management scale data on animal density and satellite derived vegetation maps (i.e. up-scaling processes).Our previous project has already demonstrated a direct impact on management in the Setesdal Vesthei and Hardangervidda region, and the outcomes from this proposal will be applicable to sheep grazing in alpine areas and also relevant to semi-domestic rein deer (summer) grazing management.

本研究拟进一步推进两项独特的对比性高山生态系统（alpine ecosystems）原位实验研究——其中一项于2000年在塞特瑟达尔韦斯特海（Setesdal Vesthei）启动，另一项于2002年在霍尔（Hol）启动——以回应若干关键的前沿研究议题：
本研究的总体目标为：通过建立科学依据，将放牧管理方案（绵羊种群密度（sheep density））与放牧产生的特定长期生态效应挂钩，从而助力高山生境中绵羊放牧的可持续管理。此前两项绵羊放牧实验的前6至8年观测结果显示，植物、无脊椎动物（invertebrates）、啮齿类（rodents）与鸟类的短期放牧效应存在显著差异；此外，放牧效应还受绵羊种群密度、生境生产力等因素调控。然而，此类短期影响与长期影响往往存在差异，因为多数放牧效应属于间接效应，需通过植物与土壤生态过程介导产生。
本研究的具体目标包括：
1. 在两种对比鲜明的生境类型（肥沃型与贫瘠型）中，首次开展为期10年的绵羊放牧效应长期实验研究；
2. 评估长期级联生态系统效应；
3. 评估泰加林-苔原生态交错带（taiga-tundra ecotone）的林线（tree-line）动态变化；
4. 评估土壤物理过程、生物地球化学过程（biogeochemical processes）及其理化性质；
5. 将绵羊种群密度依赖的放牧生态学与生活史特征与长期植物群落动态相结合，以明晰气候与种群密度如何在不同时间尺度上调控有蹄类（ungulate）动物的生活史；
6. 整合生态实验数据、管理尺度的动物种群密度数据与卫星遥感植被制图数据（即过程尺度上推（up-scaling processes））。
我们此前的研究项目已证实，该研究对塞特瑟达尔韦斯特海与哈当厄尔维达（Hardangervidda）地区的放牧管理具有直接指导作用；本提案的研究成果不仅可应用于高山地区的绵羊放牧管理，也对半驯养驯鹿（semi-domestic rein deer）的夏季放牧管理具有重要参考价值。