Zhao Yifei, Liu Shiliang, Dong Yuhong, Wang Fangfang, Liu Hua, Liu Yixuan
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Front Plant Sci. 2023 Jan 31;14:1051881. doi: 10.3389/fpls.2023.1051881. eCollection 2023.
Fencing is an essential measure for the rehabilitation and conservation of grasslands on the Qinghai-Tibet Plateau. However, its construction could change the distribution and migration of wildlife, thus affecting the integrity of the ecological networks for local wild animal movement. It is of great significance to quantify the potential impact of fencing on ecological network connectivity associated with land-use changes at regional scale. In this study, taking the northern Tibetan Plateau as the study area, we explored the ecological network change using circuit theory approach under different scenarios at county scale. Among them, this study set up four different scenarios according to the economic growth rate, population growth rate and the sustainable development of society and environment. The results showed that: 1) with increased grazing intensity and enhanced human activities from 1990 to 2015, the grasslands of the northern Tibetan Plateau were greatly degraded, most of which was converted into the barren land, and the conversion proportion was as high as 90.84%, which lead to a decreasing trend of the current density of ecological network in most counties and deterioration of ecological connectivity; 2) fencing construction has reduced regional current density, while fencing intensity is positively correlated with current density loss at county scale. Among them, the counties with serious current density loss were distributed in the northwest and southeast regions. The maximum loss ratio is 39.23%; 3) under four different future land use scenarios, coordinated economic, social and environmental development will have a positive effect on the ecological network. The results of the study have important ecological significance for developing reasonable conservation measures for grassland restoration, protecting wildlife, and maintaining regional ecological balance.
围栏是青藏高原草原恢复和保护的一项重要措施。然而，其建设可能会改变野生动物的分布和迁徙，从而影响当地野生动物活动生态网络的完整性。量化围栏对区域尺度上与土地利用变化相关的生态网络连通性的潜在影响具有重要意义。在本研究中，以青藏高原北部为研究区域，我们采用电路理论方法在县域尺度上探讨了不同情景下的生态网络变化。其中，本研究根据经济增长率、人口增长率以及社会和环境的可持续发展设定了四种不同情景。结果表明：1）1990年至2015年，随着放牧强度增加和人类活动增强，青藏高原北部的草原严重退化，大部分转变为荒地，转变比例高达90.84%，导致大多数县的生态网络当前密度呈下降趋势，生态连通性恶化；2）围栏建设降低了区域当前密度，而围栏强度在县域尺度上与当前密度损失呈正相关。其中，当前密度损失严重的县分布在西北部和东南部地区。最大损失率为39.23%；3）在四种不同的未来土地利用情景下，经济、社会和环境的协调发展将对生态网络产生积极影响。研究结果对于制定合理的草原恢复保护措施、保护野生动物以及维持区域生态平衡具有重要的生态意义。
