江西大岗山毛竹林土壤呼吸时空变异及模型模拟

Spatial and temporal variation of soil respiration and models of Phyllostachys pubescens in Dagangshan of Jiangxi

采用LI-8100土壤呼吸测定仪对江西大岗山地区不同海拔毛竹林土壤呼吸的时空格局变化进行了测定,同时建立了多种基于土壤温度、含水率及水热因子的土壤呼吸模型。结果表明：毛竹林土壤呼吸随海拔升高而降低,其日变化与不同深度土壤温度变化趋势基本一致,呈单峰曲线变化。土壤呼吸与地表面、地下10、20和30 cm处土壤温度显著相关（p〈0.1）,其中与地下10cm处温度相关性达到极显著水平（p〈0.05）,相比Van’tHoff模型,Lloyd、Taylor模型的拟合度R2更大;线性模型表明土壤呼吸与不同层土壤含水率相关性较小（R2=0.133~0.377）,将实测土壤呼吸标准化为10℃时的土壤呼吸R10后,R10与土壤含水率相关性显著增强（R2=0.303~0.445）;土壤水热双因子模型能进一步提高土壤呼吸模型预测能力（R2=0.450~0.768）。

An automated chamber system LI—8100 was used to study how soil respiration differed with spatial and temporal in moso bamboo（Phyllostachys pubescens） plantations on the different elevations,in Dagangshan mountain range,Jiangxi province.Different mathematical models were used to describe the relationship between soil respiration and soil temperature,soil water content.The results showed that,at the diurnal scale,soil respiration decreased with elevation and had a similar temporal trend with soil temperature.Soil temperature at different depths（soil surface,10,20 and 30 cm depth）all had significant effect on soil respiration（P0.1）,and the 10 cm depth had an very significant（P0.05） effect on soil respiration.The Van＇t Hoff model had higher R2 than Lloyd and Taylor equation.The relationship between soil water content and soil respiration was smaller and could be described by linear equation（R2=0.133—0.377）.After normalized the soil respiration at 10 ℃（R10）,the correlation between R10 and soil water content was enhanced（R2=0.303—0.445）.Compared with the R2 of one-dimensional equation,the R2 of the two-dimensional equation（R2=0.450—0.768） increased to some extent.