A remote sensing perspective of alpine grasslands on the Tibetan Plateau: Better or worse under “Tibet Warming”?

The Tibetan Plateau is a unique cold and dry highland widely known as the Earth׳s 3rd Pole. Its fragile ecosystems, especially alpine grasslands comprising 60% of the plateau, are sensitive to climate change that has been experiencing a distinct warming trend in past decades. Due to limited in-situ accessibility, studies of alpine grasslands have been heavily relying on satellite observations since 1980s. This paper gives an overview of satellite remote sensing of alpine grasslands on the plateau, and controversy findings about their phenological trends and climatic impacts. Implications of cryospheric and hydrologic processes such as snow/glacier melting, lake area change and permafrost retreat on the warming plateau are also discussed. This study reveals that satellite-extracted spatiotemporal patterns of alpine grasslands should be interpreted with caution. Under the rapidly changing climate, alpine ecosystems and their evolution paths on the Tibetan Plateau need more comprehensive, integrated investigation.