塔里木河中下游柽柳群落土壤碳通量及其影响因子分析

利用LI-8100监测塔里木河中下游柽柳群落土壤呼吸的日变化,分析了塔里木河中下游干旱荒漠区的温度、地下水和土壤水分对土壤呼吸的影响.结果表明:土壤呼吸的日变化是不规律的单峰值曲线,碳通量的最大值出现在正午12:00～16:00不等,由于受当日云量、风速等气象因子的影响,因此各个断面差异较明显.土壤呼吸与地下水位、各层温度、各层土壤含水量的关系都很显著:地下水位与柽柳根系关系密切,因此土壤碳通量与地下水之间的关系极显著,适合三次曲线模型;气温、近地表气温、地表温度与土壤碳通量成正相关关系,适合指数模型,但是15cm、20cm、25cm、30cm土层温度与土壤碳通量成负相关关系,适合三次曲线模型;土壤含水量与土壤呼吸之间存在极显著关系,适合三次曲线模型;经过多元回归分析得到土壤呼吸与温度、土壤含水量之间的关系模型可以解释67%的土壤呼吸的变化情况.

Analysis of Carbon Flux of Soil and its related factors from Tamarix spp. Community in the Middle and Lower Reaches of Tarim River

This study utilized LI-8100 automated soil CO₂ flux system to monitor the day change of carbon flux of soil from Tamarix spp.community in the middle and lower reaches of Tarim River.The influence of temperature,groundwater,and soil water on Carbon flux of soil were analyzed.The study show that the curves of day change of soil respiration have a simple peak value,but the maximum flux normally appear until 12 o'clock noon to 16 o'clock differently.Because of influence of cloud cover and wind speed in that time,difference of the day change of carbon flux of soil are obvious.The relations between the soil respiration and underground water,temperature and soil water content in every depth are close;the relations between carbon flux of soil and underground water are extremely prominent,suitable for Cubic model curve.The relations between carbon flux of soil and air temperature and air temperature near the ground surface,ground surface temperature become positively correlated,suitable for Exponent models curves.However,the relations between carbon flux of soil and soil temperature in the 15cm,20cm,25cm,30cm are negatively correlated,suitable for Cubic model curve.At last,this study analyzed the relations between carbon flux of soil and temperature and soil water content by multi-regression,which explain 67% of the changes in carbon flux of soil.