Experimentally simulating warmer and wetter climate additively improves rangeland quality on the Tibetan Plateau

1. The vast expanses of rangeland on the Tibetan Plateau, which support the livelihood of ~9.8 million local inhabitants, have experienced rapid climate warming over the past 50 years. At the same time, precipitation has increased in large parts of the Plateau but decreased in other parts, particularly in the northwest. These trends are predicted to continue into the future. However, their potential effects on rangeland quality remain unclear.
2. We conducted a two-factor field experiment in which we manipulated temperature (control or warming by 1.5–1.8 °C) and precipitation (control or 50% reduction or increase in rainfall) in an alpine grassland on the north-eastern Tibetan Plateau, starting in 2011. From 2014–2016, we measured forage production and community composition, and in 2015 forage quality (crude protein, cell soluble contents, hemicellulose, cellulose, lignin and digestibility) represented by seven abundant species.
3. Overall, warming did not change total forage producti...