矮竹扩繁引起的亚高山针叶林退化导致土壤钾和镁流失  

Subalpine Coniferous Forest Degradation Caused by Dwarf Bamboo Expansion Reduced Soil K and Mg Contents

作　　者：莫利 杨浩[2] 侯蓉 吴蔚 张龙 黄冲 杨洪 宋心强 齐敦武 MO Li;YANG Hao;HOU Rong;WU Wei;ZHANG Long;HUANG Chong;YANG Hong;SONG Xin-qiang;QI Dun-wu(Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife,Chengdu Research Base of Giant Panda Breeding,Chengdu 610081,China;CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province,Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China;Administrative Bureau of Daxiangling Nature Reserve,Yingjing 625200,China)

机构地区：[1]四川省濒危野生动物保护生物学省部共建实验室,成都大熊猫繁育研究基地,四川成都610081 [2]中国科学院山地生态恢复与生物资源利用重点实验室,生态恢复与生物多样性保育四川省重点实验室,中国科学院成都生物研究所,四川成都610041 [3]荥经县大相岭自然保护区管理局,四川荥经625200

出　　处：《长江流域资源与环境》2022年第11期2536-2544,共9页Resources and Environment in the Yangtze Basin

基　　金：国家自然科学基金项目(U21A20193);成都大熊猫繁育研究基金会项目(CPF2017-20);成都大熊猫繁育研究基地自立课题(2020CPB-B25);2019年中央财政林业科技推广示范项目([2019]28号)。

摘　　要：为明确矮竹扩张引起的退化演替对亚高山针叶林土壤钾(K)和镁(Mg)含量的影响,针对原始亚高山针叶林(原始林)、次生针阔混交林(次生林)和冷箭竹(Arundinaria faberi)灌丛(竹灌丛),进行了群落多样性、凋落物和土壤氮(N)、K和Mg含量以及土壤pH、有机质(SOM)含量等方面的比较,并利用逐步回归方法分析了影响土壤K和Mg含量的主要因素。结果表明:(1)物种个体数、物种丰富度和多样性指数随着森林退化演替而显著降低;(2)凋落物未分解层和半分解层的T_(Nlitter)、T_(Klitter)和T_(Mglitter)含量在不同退化阶段存在显著差异,其中原始林最高,竹灌丛最低;(3)随着森林退化演替至竹灌丛阶段,SOM、TN_(soil)、AN_(soil)、TK_(soil)、AK_(soil)和TMg_(soil)含量显著降低;(4)土壤N、SOM是影响土壤K和Mg含量的主要因素,其次是群落多样性;TN_(soil)对于TK_(soil)和AK_(soil)的贡献分别达到57.0%和48.0%,SOM对于AK_(soil)的贡献为35.9%,而AN_(soil)对于TMg_(soil)的贡献则为47.1%。因此,矮竹扩张引起的亚高山针叶林退化演替不仅降低了土壤C、N降低,还导致了土壤K和Mg流失。This paper studies the effects of subalpine coniferous forest degradation caused by dwarf bamboo expansion on soil K and Mg contents.We used community diversity indexes,soil pH,soil organic matter and the contents of N,K and Mgin litter and soil to compare among primary subalpine coniferous forest(PF),mixed broadleaf-conifer forest(SF)and dwarf bamboo bush(BB).In addition,stepwise regression was used to explore the main factors affecting soil K and Mg contents.The results showed that:(1)plant numbers in tree and shrub layers,species richness and diversity indexes decreased significantly with forest degradation;(2)the contents of T_(Nlitter),T_(Klitter)and T_(Mglitter)displayed significant differences among the three degradation levels,which was highest in PF,and lowest in BB;(3)with the forest degraded to bamboo bush stage,SOM,TN_(soil),AN_(soil),TK_(soil),AK_(soil)and TMg_(soil)significantly decreased;(4)stepwise regression analysis showed that TN_(soil)contributed 57.0%and 68.0%to TK_(soil)and AK_(soil),respectively,SOM contributed 35.9%to AK_(soil),and AN_(soil)contributed 47.1%to TMg_(soil),indicating that soil N and SOM content were the main factors affecting soil K and Mg contents,followed by community diversity.Our results proposed that the degradation of subalpine coniferous forest caused by dwarf bamboo expansion not only reduced soil C and N content,but also led to soil K and Mg loss.

关 键 词：矮竹 钾 镁 土壤 亚高山针叶林 退化 

分 类 号：X171[环境科学与工程—环境科学] X16