细叶云南松(Pinus yunnanensis var.tenuifolia)是南盘江流域典型的植被类型,它在该流域的水土保持、水源涵养方面扮演重要的角色,然而鲜少有人关注其林下凋落物和土壤养分特征。本研究选择经不同历史干扰后恢复形成的3种树种组成不同的细叶云南松天然次生林为对象,研究其凋落物量、凋落物养分归还量及其与土壤养分含量的相关关系。结果表明,年凋落物生物量为12462.90~14273.49kg·hm^-2,其中凋落叶生物量为4047.17~7353.23kg·hm^-2,占总量的61.1%~67.0%。凋落物生物量的月动态呈双峰型,最大值出现在4月和11月,最低值出现在9月。凋落物养分归还量以N、Ca和K较高,P较低,各组分养分归还量为针叶(16.13kg·hm^-2) >阔叶(13.20kg·hm^-2) >树枝(4.02kg·hm^-2) >杂物(10.05kg·hm^-2)。不同林分间土壤养分与各组分的营养元素归还量关系密切,其中与针叶养分归还量呈负相关,与阔叶、枝和杂物呈正相关。
Pinus yunnanensis var. tenuifolia is a typical vegetation type along the Nanpan River,it plays an important role in the soil and water conservation.However,little attention has been paid to the characteristics of litter fall and soil nutrient under the forest.This paper investigated the amount,composition and dynamic characteristics,nutrient return amount and soil nutrient of litterfall in three types of secondary forests of P.yunnanensis .The results revealed that the annual litter productions in the three forests ranged from 12 462.90 to 14 273.49 kg·hm^-2,the biomass of leaf litter was the dominant component in the total litter and contributed for about 61.1% to 67.0%,whose production ranged from 4 047.17 to 7 353.23 kg·hm^-2 .The monthly litterfall production exhibited two peaks,these three forests had the largest annual litterfall amount in the April and November,and the minimum appeared in September.The feature of litter nutrients return of each element size sequence was in the order of N >K >Ca >P >Fe >Mg >Cu.The amounts of various components of the nutrients return were coniferous (16.13 kg·hm^-2 ) >broad leaf (13.20 kg·hm^-2 ) > branch (4.02 kg·hm^-2 ) >miscellany (10.05 kg·hm^-2 ).There existed significant differences in soil nutrients among three forest types,the content of organic matter was the highest,followed by total potassium,total nitrogen,total phosphorus and available potassium,and the available phosphorus was the lowest.Soil nutrients in different plots were closely related to nutrient return of litter components,there existed negative correlation between soil nutrient and coniferous nutrient return,and positive correlation with the rest of litter components.
Journal of Northwest Forestry University
Pinus yunnanensis var. tenuifolia