Rainfall pulse response of carbon exchange to the timing of natural intra-annual rainfall in a temperate grass ecosystem

摘要: Abstract Rainfall pulses play a key role in dominating the ecosystem carbon balance arid and semiarid regions. In future, intensity frequency of rainfall events will be significantly altered. Therefore, discussing response to is extremely important for predicting effect global change on cycle. grasslands, previous studies have documented that there threshold size, above which net exchange (NEE) would shift from positive (carbon source) negative sink). However, does this exist under altered intra-annual timing during growing season? To answer question, we conducted an experiment typical grassland detect relationship between pulse seasons 2012 2015. Our showed was no NEE source sink with timing. early season, pulses. middle sink) Moreover, magnitude positively related activity duration differences respiration (ER) gross primary productivity (GPP). This study provided new perspective proximate causes effects NEE. The mechanism underlying patterns critical importance improving our ability project future changes Earth system.