Influence of short-term experimental warming on heat-waterprocesses of the active layer in a swamp meadow ecosystemof the Qinghai-Tibet Plateau

摘要

Climate change is now evident in the Qinghai-Tibet Plateau （QTP）, with impacts on the alpine ecosystem, particularlyon water and heat balance between the active layer and the atmosphere. Thus, we document the basic characteristics ofchanges in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadowecosystem. Data sets under open top chambers （OTC） and the control manipulations were collected over a completeyear. The results show that annual （2008） air temperatures of OTC-1 and OTC-2 were 6.7 °C and 3.5 °C warmer than thecontrol. Rising temperature promotes plant growth and development. The freeze-thaw and isothermal days of OTCsappeared more frequently than the control, owing to comparably higher water and better vegetation conditions. OTCssoil moisture decreased with the decrease of soil depth; however, there was an obviously middle dry aquifer of thecontrol, which is familiar in QTP. Moreover, experimental warming led to an increase in topsoil water content due topoorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons. The results ofthis study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climatechange.