Grasslands are important terrestrial ecosystems occupying >30% of the global land area and providing numerous ecosystem services. As global climate change has accelerated in recent years, the increased frequency of extreme droughts has negatively impacted aboveground net primary productivity (ANPP) of grasslands.  The ability of plants to survive and recover from drought is critical for maintaining semiarid grassland ANPP, but our understanding of the mechanisms underlying plant responses to drought remains limited.

Plant bud and shoot densities play important roles in regulating population persistence and community recovery following drought. In most grasslands, bud bank traits play a more important role in community maintenance and regeneration following disturbances and environmental changes than the seed bank. For example, >99% of aboveground shoots were recruited from belowground axillary buds while only 1% emerged from seeds. Yet, it remains unclear how bud bank traits respond to drought and how such responses affect ANPP.

To address this knowledge gap, a research team from the Institute of Applied Ecology of the Chinese Academy of Sciences conducted a six-year drought manipulation experiment in four arid and semiarid grasslands that consisted of a four-year drought, followed by a two years recovery. They assessed the resistance and resilience of ANPP and community bud bank traits to drought and recovery.

They found that experimental drought exerted little and inconsistent effects on bud bank traits. Interestingly, they observed a strong relationship between ANPP resilience and bud bank. Together, these results highlight the importance role of bud bank traits in understanding drought and recovery effects on grassland functions.

These results will broadly improve our understanding of ecosystem resistance and resilience to extreme drought and could motivate further study into the impacts of bud bank traits on ecosystem functions.

Relevant results have been published in Journal of Ecology entitled "High below-ground bud abundance increases ecosystem recovery from drought across arid and semiarid grasslands "

YUE Qian

Institute of Applied Ecology, Chinese Academy of Sciences

Tel: 86-24-83970317

E-mail: yueqian@iae.ac.cn

Web: http://english.iae.cas.cn