Ji Suonan, Aimée T. Classen, Zhenhua Zhang, and Jin-Sheng He
Climate warming, especially winter warming, will have cascading impacts on the “roof of the world”. The Tibetan Plateau is the world’s highest and largest plateau, and it is also called “the third pole” after the Arctic and Antarctic. As one of the regions most sensitive and vulnerable to climate change, this plateau has experienced a rapid warming in recent decades. Importantly, warming patterns will not be equal across seasons, and winters are predicted to warm more than summers. While climate warming generally advances plant phenology, i.e. leaf-out or flowering time, some studies have reported that a warmer winter has the opposite impact on plant growth. This is perhaps because a certain amount of chilling is required to break dormancy during winter, otherwise the development of the plant will be delayed. However, our present study revealed that winter warming will not delay, but advance plant phenology on the Tibetan Plateau. More importantly, the impact of winter warming is more serious than climate warming distributed equally between seasons. In addition, plant species responded differently to winter warming, such that species that flower in June to July are more sensitive to warming than species that flower in early May. These impacts will result in dramatic changes in plant growth, plant–animal interactions, ecosystem services and carbon cycle of the Tibetan Plateau. Thousands of glaciers and other geographical and ecological features serve as a “water tower”, storing water and maintaining river flow on the Tibetan Plateau, which contains the headwaters of the drainage basins of most of the streams in surrounding regions. The cascading impacts of climatic winter warming will reduce the biodiversity of this area, harm the ecosystem’s ability to store water and the capacity for sustainable development as well. Therefore, more attention should be paid to protecting and managing the Tibetan Plateau in the future climate change.
Photograph credit: Jin-Sheng He