Existent nature reserves not optimal for water service provision and conservation on the Qinghai-Tibet Plateau of China

Abstract

Water ecosystem services dynamically connect human society and the biosphere across spatiotemporal scales to finally support socioeconomic development and human well-being. Water ecosystem services are usually abundant in the so-called water tower regions which comprise mainly the mountains and plateaus where many big rivers originate. However, these water tower regions are also ecologically vulnerable to natural and anthropogenic disturbances. Furthermore, the effectiveness of conservation management on water ecosystem services in these regions is still not so clear. We developed a biophysical-based composite water ecosystem service index (ES w ) for quantifying and mapping the spatial patterns and temporal changes of water ecosystem services on a large regional scale. We apply this approach to the Qinghai-Tibet Plateau (QTP) in southwestern China, the world’s largest and most highly protected water tower region. The results show that the areas with a high level of ES w as the priority areas for conservation account for 39.88% of the QTP with a spatially heterogeneous distribution among river basins and nature reserves. But these nature reserves accommodate only 22.52% of the priority areas with large conservation gaps in the river basins and at local scales. The nature reserves are effective in mitigating water ecosystem services degradation and facilitating their restoration. Therefore, the spatial optimization of nature conservation can be addressed for the sustainable management of the ecosystems and their water ecosystem services to support well-being of local and downstream societies. The assessment method formulated in this research is adaptable to other similar water tower regions.