摘要
凋落物分解释放的化学成分会对植物生长产生促进或抑制作用.以往研究主要关注同一植物群落中的凋落物对幼苗更新的影响,不同演替阶段(草地、灌丛、针阔混交林、针叶林)植物物种能与先锋树种短期共存,为了解其产生的凋落物对先锋树种生长的影响研究,选择川西亚高山森林各演替阶段4种代表性植物凋落物进行凋落物添加盆栽模拟实验,研究凋落物分解对土壤理化性质、土壤酶活性和白桦幼苗生长的影响.结果显示:(1)相对于未添加凋落物对照处理,尼泊尔酸模(Rumex nepalensis)和云杉(Picea asperata)凋落物显著促进白桦幼苗生长,沙棘(Hippophae rhamnoides)和白桦(Betula platyphylla)凋落物显著抑制白桦生长.(2)云杉凋落物分解后,土壤NH_(4)^(+)-N、微生物生物量碳(MBC)、微生物生物量氮(MBN)、N-乙酰-β-D-葡萄糖苷酶(NAG)和β-1,4-葡萄糖苷酶(BG)活性显著增加;沙棘凋落物分解后,土壤NH_(4)^(+)-N、MBN、NAG和BG显著降低;尼泊尔酸模和白桦凋落物对土壤NH_(4)^(+)-N、MBC、MBN和BG无显著影响,但显著降低NAG活性.(3)土壤中的NH_(4)^(+)-N、MBN、BG和NAG与白桦生物量呈极显著正相关(P<0.01),而NO_(3)^(-)-N与白桦生物量呈极显著负相关(P<0.01).因此,添加凋落物会影响土壤酶(如BG和NAG)活性,改变NH_(4)^(+)-N和NO_(3)^(-)-N含量,进而影响白桦生长.本研究有助于进一步认识森林恢复演替过程中白桦幼苗生长的调控因子.在亚高山森林恢复中后期阶段,应考虑同时配置粗枝云杉或尼泊尔酸模等物种,产生凋落物正反馈作用,以促进先锋树种白桦定居成功.
Chemical compounds from litter decomposition may exhibit stimulatory or inhibitory effects on plant growth.Previous studies have primarily focused on how litter influences seedling regeneration in the same plant community.However,plant species at different succession stages(grassland,shrub,mixed coniferous and broad-leaved forest,and coniferous forest)can coexist with pioneer tree species for a short time,and few studies have investigated the effects of litter from different succession stages on the growth of pioneer tree species.In this study,Betula platyphylla seedlings were grown in pots with bulk soils and four representative plant litter inputs from different succession stages in western Sichuan.This study aimed to investigate the effects of litter decomposition on soil physicochemical properties,soil enzyme activities,and B.platyphylla growth.The results showed that(1)the litters of Rumex nepalensis and Picea asperata significantly promoted the growth of B.platyphylla,whereas Hippophae rhamnoides and B.platyphylla litter significantly inhibited B.platyphylla growth compared to the control pots.(2)After P.asperata litter decomposition,the contents of soil NH_(4)^(+)-N,microbial biomass carbon(MBC)and microbial biomass nitrogen(MBN),and the activities of N-acetyl-β-D-glucosidase(NAG)andβ-1,4-glucosesidase(BG)significantly increased.The contents of NH_(4)^(+)-N and MBN,and the activities of NAG and BG significantly decreased with the H.rhamnoides litter decomposition.In addition,R.nepalensis and B.platyphylla litters had no significant effects on NH_(4)^(+)-N,MBC,MBN,or BG,but significantly reduced NAG activity.(3)The soil biological(MBN,BG,and NAG)and chemical(especially NH_(4)^(+)-N)properties were significantly positively correlated with B.platyphylla biomass(P<0.01),whereas NO_(3)^(-)-N was significantly negatively correlated with B.platyphylla biomass(P<0.01).These results indicated that litter decomposition significantly altered soil enzyme activities(BG and NAG)as well as NH_(4)^(+)-N and NO_(3)^(-)-N contents,which indirectly affected plant growth.In the middle and late stages of subalpine forest restoration,some species,such as P.asperata or R.nepalensis,produce positive litter feedback to promote successful settlement of B.platyphylla,a pioneer species.
作者
陈静
赵文强
贺合亮
罗林
刘庆
阳小成
CHEN Jing;ZHAO Wenqiang;HE Heliang;LUO Lin;LIU Qing;YANG Xiaocheng(College of Ecology and Environment,Chengdu University of Technology,Chengdu 610059,China;CAS Key Laboratory 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;University of Chinese Academy of Sciences,Beijing 100049,China;Yibin University,Yibin 644000,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2021年第3期686-693,共8页
Chinese Journal of Applied and Environmental Biology
基金
国家重点研发计划项目(2017YFC0505000)
国家自然科学基金面上项目(31870607)资助。
关键词
凋落物
演替阶段
白桦
土壤酶活
土壤微生物生物量
植物生长
亚高山森林
litter
successional stage
Betula platyphylla
soil enzyme activity
soil microbial biomass
plant growth
subalpine forest
