川西亚高山3个优势树种不同径级根系分解特征  

Decomposition and nutrient release of root with different diameters of three subalpine dominant trees in western area of Sichuan Province,China

作　　者：唐仕姗 杨万勤[1] 王海鹏[2] 熊莉[1] 聂富育 徐振锋[1] 

机构地区：[1]四川农业大学生态林业研究所四川林业生态工程重点实验室,成都611130 [2]四川农业大学水稻研究所,成都611130

出　　处：《应用生态学报》2015年第10期2921-2927,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31170423;31200474;31270498);"十二五"国家科技支撑计划项目(2011BAC09B05);四川省杰出青年学术与技术带头人培育项目(2012JQ0008;012JQ0059);中国博士后科学基金项目(2013M540714;2012T50782;2014T70880);四川省教育厅重点项目(12ZA105)资助

摘　　要：采用埋袋法对川西亚高山3个优势树种（岷江冷杉、粗枝云杉和红桦）细根（≤2mm）、中根（2-5 mm）和粗根（≥5 mm）质量损失率及碳（C）、氮（N）、磷（P）在经历生长季和非生长季之后释放特征进行研究.结果表明：红桦质量残留率低于岷江冷杉和粗枝云杉.同一树种,质量残留率总体上随根系径级增加而增加.非生长季的质量损失率占全年质量损失率的52.1%-64.4%.红桦C释放率最高,岷江冷杉最低,且随根系直径的增粗,C释放率降低.岷江冷杉和粗枝云杉N释放模式为非生长季富集、生长季释放,而红桦反之.富集期间,径级越大,富集量越多.3个树种各径级根系P动态在非生长季和生长季皆表现为富集-释放模式,且岷江冷杉P富集程度显著高于粗枝云杉和红桦,但各径级之间差异总体不显著.根系径级对川西亚高山森林根系分解具有显著影响,而径级影响与树种和分解时期有一定关系.In this study,a buried bag experiment was used to investigate mass loss and C,N and P release patterns of fine（ ≤2 mm）,medium（ 2- 5 mm） and coarse（ ≥5 mm） roots of 3 subalpine dominant trees,i. e.,Betula albosinensis,Abies faxoniana and Picea asperata in the growing and non-growing seasons. In general,the remaining mass of B. albosinensis was lower than that of A.faxoniana and P. asperata. In addition,root remaining mass increased with the increase of root diameter for the same species. The mass losing rate in the non-growing season was 52. 1%- 64. 4% of a year. The C release of B. albosinensis was the highest,but that of A. faxoniana was the lowest.Also,C release decreased with the increase of root diameter. N of A. faxoniana and P. asperata were enriched in the non-growing season but released in the growing season. However,the opposite pattern was found for B. albosinensis. During the non-growing season,the amount of N enrichment increased with the increase of root diameter. The P release of 3 species was characterized as the enrichment-release pattern. P enrichment of A. faxoniana was significantly greater than that of P. asperata and B. albosinensis. Nevertheless,no significant difference was observed between diameter sizes. In conclusion,diameter size had significant effect on root decomposition in the subalpine forests of western Sichuan,and the diameter effect was dependent on tree species and season.

关 键 词：径级 质量损失率 养分释放 

分 类 号：S718.4[农业科学—林学]