Effectiveness of protected areas edges on vegetation greenness, cover and productivity on the Tibetan Plateau, China

Protected areas (PAs) are the cornerstones of global vegetation conservation efforts, but growing evidence showed the limited effectiveness of PAs in some regions. Recent attempts to quantify conservation efficiency were mainly focused on vegetation coverage, overlooking other vegetation characteristics, such as greenness and productivity. Here, using multiple indices of vegetation status from satellite observations and a windows search strategy, we measured the conservation efficiency of nature reserves (NRs, the primary category of PAs in China) edge on vegetation greenness, cover, and productivity on the Tibetan Plateau. The results showed that NRs’ edges performed a weak, but significant role in vegetation growth. Over 40% of the areas showed a positive impact of NRs’ edge on vegetation growth in different degrees. However, about 10% of the areas located on NRs’ edge showed a noticeable opposite effect on greenness, cover, and productivity. Compared to some climatic and socio-economic factors (e.g., population density and air temperature), fragmented landscapes and landforms are more likely to inhibit conservation efficiency. The findings of this work can help better understand PAs’ role in securing vegetation conservation and optimize the design of PAs for preventing vegetation losses.