不同水分处理和枯落物分解对闽江河口湿地土壤CO2释放的影响

Effects of Different Water Treatment and Decomposition of Litter on Release of Soil CO2 in Minjiang river Estuary Wetland

水分和枯落物分解是影响湿地土壤CO2释放的重要因子,以闽江河口短叶江芏(Cyperus malaccensisvar.brevifolinus)湿地土壤为研究对象,通过设置不同水分条件[70%、100%、130%土壤饱和含水量(SSM)]和枯落物添加处理,研究湿地土壤CO2释放对不同水分处理以及枯落物添加的响应。结果表明:(1)各处理的土壤CO2释放速率在30 d的培养期内均呈现先升高后波动下降的趋势,各水分处理的土壤CO2累积释放量均随培养时间的增加而增加,在前8—15 d增长较快,后15 d增长较慢;(2)不同土壤水分处理对湿地土壤CO2释放影响显著,未添加枯落物处理中,100%SSM处理的土壤CO2释放速率和累积释放量显著最高,130%SSM的处理显著最低(P<0.01);枯落物添加处理中,130%SSM处理的土壤CO2释放速率和累积释放量显著最高,70%SSM处理的显著最低(P<0.01);(3)枯落物的添加并未改变土壤CO2释放速率随时间变化的趋势,但显著促进各处理的土壤CO2释放量(P<0.01)。

Water treatment and litter decomposition are important factors affecting CO2 release from wetland soil.the objective of was by investigation the soils of the Cyperus malaccensis var.brevifolinus Wetlands of the Minjiang river Estuary to study the responses of CO2 release from wetland soil to different water treatment and litter addition by setting different moisture conditions[70%,100%,130%soil saturated moisture(SSM)]and adding litter.The results showed that:(1)the soil CO2 release rates of all treatments displayed a dynamic trend of first increasing followed by a fluctuating decrease during the culture period.The cumulative CO2 release of soil under all water treatments increased with the increase of culture time.(2)Different soil water treatments have significant influence on the CO2 release from wetland soil.in the treatment without litter addition,the CO2 release rate and cumulative release amount from soil under 100%ssM treatment were the highest and 130%ssM treatment was the lowest(P<0.01).in the treatment with addition of litter,130%ssM treatment had the highest CO2 release rate and cumulative release,while 70%ssM treatment had the lowest(P<0.01).(3)The addition of litter did not change the trend of soil CO2 release with time,but significantly promoted the soil CO2 release under all treatments(P<0.01).