川西亚高山典型针叶林凋落物有机碳归还特征

Carbon Return Patterns from Litterfall in TypicalSubalpine Coniferous Forests in Western Sichuan

凋落物是维持森林生态系统碳循环的关键因素,也是土壤有机碳的主要来源。以四川省理县毕棚沟自然保护区典型针叶林(岷江冷杉林)和粗枝云杉林为研究对象,比较不同凋落物组成(叶、枝、树皮、附生植物、果、花)和不同类型凋落叶(乔木和灌木、常绿和落叶、针叶和阔叶)的总有机碳归还特征。研究结果显示,岷江冷杉林凋落物总有机碳归还量比粗枝云杉林高约37%。其中,叶和枝对凋落物总有机碳归还量的贡献之和高达70%。粗枝云杉林中,落叶和阔叶凋落叶总有机碳归还量高于常绿和针叶,而岷江冷杉林则相反。结果证实了原始岷江冷杉林在维持区域生态系统碳循环方面具有更加重要的作用,对进一步提升区域森林经营管理水平及固碳增汇具有重要意义。

Litterfall is a key factor in maintaining the carbon cycle of forest ecosystems and is also a major source of soil organic carbon.This study focuses on the typical coniferous forests in the Bipenggou Natural Reserve in Li County,Sichuan Province,specifically the Abies faxoniana forest and the Picea asperata forest,comparing the distribution characteristics of total organic carbon(TOC)return from different litter components(foliage,branches,bark,epiphytes,fruits,seeds,and flowers)and different types of foliar litter(tree vs.shrub,evergreen vs.deciduous,coniferous vs.broadleaved).The results show that the TOC return from litterfall in the Abies faxoniana forest is approximately 37%higher than that in the Picea asperata forest.In both forests,the contributions of foliage and branches to the TOC return from litter account for as much as 70%.Furthermore,in the Picea asperata forest,the TOC return of foliar litter in deciduous and broadleaved species is higher than that in evergreen and coniferous species,while the opposite is true in the Abies faxoniana forest.These results confirm that the natural Abies faxoniana forest plays a more significant role in maintaining the carbon cycle of the regional ecosystem,which is of great importance for further improving regional forest management practices and enhancing carbon sequestration.