森林放牧对东北虎豹国家公园东部有蹄类动物灌草层食物资源的影响

森林放牧是中国东北虎豹国家公园内影响最广泛且强度最大的人类干扰之一。研究放牧对有蹄类动物食物资源的影响，是估算当前状态下东北虎和东北豹主要猎物承载力的关键，可以为国家公园的管理提供有效的科学依据。本研究于2016年在中国东北虎豹国家公园东部的牧场和非牧场区域分层抽取50个林下样地设置围栏对照实验，于2017年生长季进行灌草层植被调查 (每个样地的围栏与对照各随机调查3个1m×1m的样方，共调查300个植物样方) ，并应用红外相机技术获取对照样地内有蹄类动物丰富度和活动情况，研究放牧对研究区灌草层植物及动物的影响。研究结果显示：在生长季内，森林放牧显著降低林下灌草层植物生物量 (减少约24%)，牧场样地的嫩枝叶显著降低。除禾草外，牧场样地中其他类别植物的氮含量均显著高于非牧场样地 (平均超出非牧场样地25 %)。非牧场样地梅花鹿的相 对丰富度指数 (RAI) 显著高于牧场样地，而狍与野猪的相对丰富度指数 (RAI) 在这两类样地之间没有显著差别。研究结果表明，东北虎豹国家公园东部森林放牧，减少了有蹄类动物灌草层食物资源，降低了有蹄类动物的多度。建议停止森林放牧，恢复有蹄类动物栖息地。

Forest cattle grazing affects understory food resource of ungulates in the eastern part of the Northeast Tiger and Leopard National Park

Forest cattle grazing is known as the most extensive and influential human disturbance in the Northeast Tiger and Leopard National Park. The study of cattles’ effects on plant food resources of ungulates is not only the key to facilitating the estimation of carrying capacity of the ecosystem in supporting populations of ungulates, but also provides strong support for the comprehensive management and conservation tasks of the park. In 2016, sampling locations were selected by stratified sampling from grazed and ungrazed region in the east part of national park and experimental enclosures and controls were established at each location. Three hundred 1m2 plant plots were surveyed and harvested in the growing season of 2017. In the meanwhile, we also collected the ungulates’ abundance by camera-traps within each control point to study the grazing effects on shrub layer and ungulates. In general, the forest cattle grazing in our study area significantly reduced the above-ground biomass of shrub and herbage layer by 24%. Tender twigs/leaves were significantly reduced by the cattle in the grazed region. In addition, the nitrogen contents of understory except for grasses in the grazed region were significantly higher than those in the ungrazed region. Moreover, we found Relative Abundance Indices (RAI) of sika deer (Cervus nippon) from ungrazed regions were significantly h igher than those of grazed regions. However, there was no difference between grazed and ungrazed regions for the RAI of roe deer (Capreolus pygargus) or wild boar (Sus scrofa). In summary, forest cattle grazing reduced understory food resources and the abundances of ungulates in the east part of the Northeast Tiger and Leopard National Park. With the study results, we suggest to stop forest cattle grazing immediately for recovering the habitat of ungulates.