Human footprint in Tibet: Assessing the spatial layout and effectiveness of nature reserves

Humanity is causing dramatic changes to the Earth, and we may be entering a human-dominated era referred to as the Anthropocene. Mapping the human footprint and assessing the spatial layout and effectiveness of protected areas facilitate sustainable development. As the core region of the third pole, Tibet is an important area for biodiversity and the provision of ecosystem services. In this study, five categories of human pressure were summed cumulatively to map the human footprint in Tibet for 1990 and 2010, and the spatial relationship between the human footprint and national and provincial nature reserves (NRs) in Tibet was analyzed. In addition, the human footprint map was also used to evaluate the effectiveness of national and provincial NRs for reducing the impact of human activities. A comprehensive assessment was undertaken for the Yarlung Zangbo Grand Canyon (YZGC) NR. There were several key findings from this study. First, the human footprint scores (HFS) in Tibet for 1990 and 2010 were low, and increased by 32.35% during 1990-2010, which was greater than the global value of 9% for 1993-2009, indicating that Tibet is seriously threatened by human pressure. Grazing intensity and road disturbance intensity contributed significantly to the increase in the HFS. Second, the average HFS for 1990 in NRs was lower than that for the entire Tibet, but the spatial layout and extent of some reserves (e.g., the Qomolangma NR) needs to be optimized further. Third, the establishment of NRs in Tibet was effective in reducing human activities. No leakage phenomena were identified in the regions surrounding the YZGC reserve. However, the management of NRs in Tibet is still challenging in terms of reducing human activities.