降雪对生物土壤结皮光合及呼吸作用的影响

Effects of Snow on Photosynthesis and Respiration of Two Kinds of Biological Soil Crusts in Shapotou,Ningxia,China

通过对降雪处理下2种生物土壤结皮(藓类结皮和藻类结皮)光合及呼吸作用的测定,研究了降雪后生物土壤结皮净光合速率和呼吸速率的变化特征。结果表明:冬季生物土壤结皮净光合速率、呼吸速率受空气温度、辐射及土壤水分的影响,水分是关键影响因子;生物土壤结皮的光合及呼吸作用主要有3个阶段性的变化;降雪后生物土壤结皮的净光合速率和呼吸速率都会先增加后降低;生物土壤结皮的净光合速率和呼吸速率变化会受到积雪覆盖、降雪改变温度及水分的影响;生物土壤结皮净光合速率、呼吸速率与降雪量正相关。本研究证实了冬季生物土壤结皮的光合与呼吸作用不可忽略,对全球碳循环过程有重要意义。

Based on continuous measurements of photosynthesis,respiration after different snowfall,We studied the rule of the photosynthesis and respiration of the two kinds of biological soil crusts(soil algal and moss crusts).The result is that a significant positive effect of water,the air temperature and radiation on net photosynthetic rates and respiratory rates were found on the two types of biological soil crusts after snow and the water of the soil is the key effect factor of photosynthesis and respiration of the two kinds of biological soil crusts.There are mainly three stages of the photosynthesis and respiration of the two kinds of biological soil crusts during this experiment.And there was an initial increase and later decrease in net photolytic and respiration rates of each type of crusts after the snow.The net photosynthesis and respiration of the biological soil crusts under different amount of snow would be affected by three aspects which are snow cover and water and temperature change that supplied by the snow.And it suggests that there is a significant positive effect of the amount of snow on net photosynthetic rates and respiratory rates.Our study suggested that the photosynthesis and respiration of the biological soil crusts is not ignorable in winner,and it plays a very important role in the global carbon exchange.