Phenological changes offset the warming effects on biomass production in an alpine meadow on the Qinghai-Tibetan Plateau

1. Phenology is an important indicator of plant response to environmental changes and is closely correlated with biomass production. However, how changes of phenological events affect plant biomass production when exposed to changing temperature and precipitation remains unclear.

2. We conducted a four-year manipulative experiment of warming and precipitation addition to explore phenology-biomass interactions under climate change in a dry alpine meadow on the central Qinghai-Tibetan Plateau from 2015 to 2018.

3. In dry and warm years, warming delayed phenology and precipitation addition advanced them. Warming decreased biomass of Kobresia pygmaea in 2018 and biomass of Poa pratensis in 2015, 2017 and 2018. However, precipitation addition significantly increased the biomass of Poa pratensis and Potentilla multifida in most of the experimental years. Phenological changes regulated the responses of biomass to treatments. Specifically, delay of green up of P. pratensis and delay of wi...