塔里木河中游不同生境胡杨林土壤有机碳及活性组分特征OA北大核心CSTPCD

Taken the typical Populus euphratica riparian forests in different habitats in the middle reaches of the Tarim River as the research objects,the variation characteristics of soil organic carbon(SOC)and active components in 0-100 cm soil layer in xerophytic,mesophytic and periodically flooded habitats were analyzed.The results showed that 1)The average SOC content of P.euphratica forests in the three habi-tats was mesophytic(3.65 g/kg)＞xerophytic(3.56 g/kg)＞periodic flooding(3.35 g/kg).The SOC con-tent decreased with the increase of soil depth.2)The average soil microbial biomass carbon(MBC)content in the three habitats was mesophytic(408.93 mg/kg)＞periodically flooded(289.80 mg/kg)＞xerophytic(182.75 mg/kg).The readily oxidizable carbon(EOC)and dissolved organic carbon(DOC)contents were periodically flooded(2.28 g/kg,104.39 mg/kg)＞mesophytic(1.92 g/kg,67.40 mg/kg)＞xerophytic(1.89 g/kg,57.79 mg/kg).With the increase of soil depth,EOC content increased and then decreased,while DOC content showed a decreasing trend.There were significant differences in MBC among different habitats and soil layers(P＜0.05).Significant differences in EOC were found only between surface layer(0-10 cm)and the bottom layer(60-100 cm)soil(P＜0.05).There were significant differences in DOC between soil layers in Mesozoic habitats(P＜0.05).3)MBC/SOC in 40-100 cm soil layer,EOC/SOC in 20-60 cm soil layer and DOC/SOC in 10-100 cm soil layer were significantly different among the three habitats(P＜0.05).4)There was a significantly positive correlation between SOC and DOC in the three habitats(r＞0.58,n=15),and the correlation between active components was the most significant in the Mesozoic habitats.Based on the above analysis,different habitats and soil layers have significant effects on SOC and active component contents.The xerophytic and periodically flooded habitats maintained a higher SOC and active component content in 0-20 cm soil layer,while the mesophytic habitats maintained a high-er SOC allocation ratio in 20-40 cm soil layer,and the soil microbial activity is the highest.SOC conver-sion rate is high.