摘要
林地枯落物分解率是研究森林生态系统养分循环的重要内容之一 ,传统的尼龙网袋实测法虽然能提供某一具体年份枯落物分解率的准确数据 ,但因其费时费力且不能反映整个历史时期的平均水平而难以推广。基于林地枯落物积累平衡原理 ,首次提出了利用枯落物平衡模型推算枯落物分解率的方法 (简称平衡法 ) ,并将之应用于黄土残塬沟壑区剌槐林地枯落物分解率的计算。这种由平衡法推算所得枯落物分解率能反映林地的历史水平 ,弥补了尼龙网袋实测法的不足 。
Litter decay rate is one important content of the nutrient cycle research of forest ecosystems. The traditional field method is to leave litter samples in nylon string bags on the forestland and measure its periodically. Although this method can afford us the accurate data of litter decay rate in a particular year, it is difficult to popularize because of its time and effort consuming and useless to reflect the mean level in the whole life of the forest. In addition, this field method can not guarantee its precision because of errors caused by sample quantity and measuring process. In view of this, the author, in accordance with the balance principle that present litter accumulation in the forestland results from the decomposition of annual fallen litter in the past years, puts forward a new method that utilizing the litter balance model to calculate the litter decay rate (balance method in abbreviation), with formula as follows:W n =ρ(1-λ) a (D n b e -k +D n-1 b e -2k + D n-2 b e -3k +……+D 1 b e -nk) =ρ(1-λ) a ∑n-1i=0D n-i b e -(i+1)k W n——Litter accumulation in forestland(kg/tree); ρ——Increasing coefficient;λ——Dry weight loss ratio of leaves before falling; D——Average breast-high diameter of trees(cm); k——Olson coefficient; n——Age of trees; a, b——Coefficient After this model being applied in the research of black locust forestland in the Gulled Loess Plateau, it is proved that this litter decay rate on balance method can very well reflect the mean level in the whole life of the forestland and remedy the defect of field method. For the above-mentioned reasons, the author suggests that the balance method be used in the research of forest ecosystems.
出处
《生态学报》
CAS
CSCD
北大核心
2002年第6期954-956,共3页
Acta Ecologica Sinica
基金
国家"九五"攻关资助项目 ( 96 -0 0 4 -0 5 -0 7)
中科院国家重点实验室基金资助项目 ( 96 W0 0 6 )
