Changes in phenology in the Tibetan Plateau under climate change

Phenology is expected to be one of the most sensitive and easily observable natural indicators of climate change. Accelerated warming of the Tibetan Plateau (TP) since the mid-1980s has resulted in significant environmental changes. These new conditions are accompanied by phenological changes that are characterized by considerable spatiotemporal heterogeneity. The impacts of climate change and human activity on phenology were significant in the Qinghai-Tibetan Plateau; accelerated warming and optimal grazing advanced the timings of green-up and flowering but it delayed the end date of senescence. However, the timing of fruiting was relatively stable compared with that of the other phenophases. These changes were mainly caused by changes in temperature, moisture, and grazing. Warming and excessive rainfall and moderate grazing contributed to advanced and long phenophases, whereas warming and drought led to delayed and shortened phenophases. The changes in phenophases had significant influences on the structure and function of population, community, and ecosystem. However, currently, there are few studies on phenology, especially effects of changes in phenology on the structure and function of the ecosystem of the Tibetan plateau. Therefore, we need to pay more attention to effects of climate change on alpine plant phenological response from the physiological-level to ecosystem-level and to the feedback of phenology on the structure and function of ecosystems in the future.