侵蚀红壤植被恢复过程中土壤呼吸与土壤性质的关系

Relationship between soil respiration and soil properties during the revegetation of eroded red soil in subtropics of China

土壤性质是影响土壤呼吸的重要因素。研究了植被恢复对红壤侵蚀裸地土壤呼吸的影响,并探讨了土壤呼吸速率与土壤性质的关系。红壤侵蚀裸地土壤呼吸年平均速率仅0.43μmo.lm-.2s-1,恢复为百喜草地、板栗园和马尾松林后土壤呼吸速率增加了3.3-6.1倍,但仍显著低于次生林的土壤呼吸速率。土壤呼吸速率与土壤表层0-20 cm内有机C、全N、有效性N、C/N均有显著的正相关关系,但除C/N外,其相关性均随取样深度增加而下降。而土壤呼吸速率与土壤全P、有效P、全K、速效K没有显著相关关系,与土壤容重和土壤表层团聚体破坏率则呈显著负相关。因此,在红壤严重侵蚀地恢复过程中,土壤性质的恢复尤其是C、N和表层土壤结构是决定土壤呼吸速率大小的重要因素。

Soil properties is an important factor affecting soil respiration. The effects of revegetating in eroded bare land on soil respiration was investigated in red soil regions of subtropical China, and the relationship between rate of soil respiration and soil properties was discussed in this study. The annual average rate of soil respiration was only 0.43 μmol·m^-2·s^-1 in eroded bare land, and soil respiration average rates increased by 3.3 -6.1 times in three ecosystems which were restored from bare land to Paspalum noraturn Flugge grassland, Castanea mollissirna plantation and Pinus massoniana plantation, but these rates were still significantly lower than that of secondary forest. There had significantly positive correlation between soil respiration rate and soil organic C, total N, hydrolyzable N and C/N in surface soil （0 -20 cm）, and the correlation coefficient deereased with the sampling depth of soil profile but C/N; whereas they had no significant relationship with soil respiration rate and soil total P, available P, total K and available K; on the contrary, soil respiration rate had a significant negative correlation with soil bulk density and aggregate damage rate in surface soil （0 - 10 cm）. Therefore, soil properties especially soil C, N and soil structure are important determinants of soil respiration during the recovery of eroded red soil.