普定喀斯特地区不同演替群落叶凋落物分解动态

Decomposition Dynamics of Leaf Litters at Different Successional Communities in Karst Area of Puding

凋落物分解是陆地生态系统碳循环的重要环节,本研究对普定喀斯特地区4个演替群落(藤刺灌丛、灌木林、乔灌过渡林及次生乔木林)叶凋落物分解过程中的质量损失、C和N含量及释放率进行了为期两年的监测。结果表明:随着群落正向演替的推进,叶凋落物分解速率变慢;随着分解时间的推进,C、N的释放率出现递增的趋势。从群落水平来看,4种演替群落叶凋落物C/N值变化与其分解速率一致,均表现为乔灌过渡林>次生乔木林>灌木林>藤刺灌丛,相关分析表明C/N值是反映喀斯特地区凋落物分解的重要因子。

Decomposition of litters is an important composition of carbon budget in terrestrial ecosystems.In this paper,an observation was conducted on the dynamic changes of weight loss,the C and N contents and their release rates during the decomposition of leaf litters from the plant communities at four succession communities(thorny shrub,shrub,shrub-tree transitional forest and secondary forest)in the karst area of Puding for 2 years.The results showed that,with the forward succession of the communities,the decomposition rate of leaf litters slowed down,and with the advancement of decomposition time,the release rates of C and N showed an increasing trend.From a community level perspective,the C/N value of leaf litters was consistent with the decomposition rate in the four succession communities,which all showing as follows:shrub-tree transitional forest>secondary forest>shrub forest>thorny shrub.Correlation analysis showed that C/N value was an important factor reflecting the decomposition of litter in karst areas.