中国西南喀斯特地区植被自然恢复演替典型群落土壤碳氮储量特征  

Characteristics of Soil Carbon and Nitrogen Storage in Typical Communities of Natural Restoration and Succession of Vegetation in Karst Areas of Southwest China

作　　者：张跃进 李沁谊 王好才 时伟宇 Zhang Yuejin;Li Qinyi;Wang Haocai;Shi Weiyu(Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical Sciences,Southwest University,Chongqing 400715)

机构地区：[1]重庆金佛山喀斯特生态系统国家野外科学观测研究站西南大学地理科学学院,重庆400715

出　　处：《林业科学》2023年第7期45-53,共9页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(41975114);重庆市杰出青年科学基金项目(cstc2021jcyjjqX0025)。

摘　　要：[目的]探究西南喀斯特地区植被自然恢复演替过程中典型群落的土壤碳氮储量变化特征,为该地区退化生态系统恢复与重建提供参考。[方法]采用空间代时间方法,在重庆市中梁山喀斯特槽谷选取弃耕地(弃耕半年)、草地(5~10年)、灌丛(15~25年)、灌乔林(30~40年)和乔木林(50~60年)作为一个植被自然恢复演替序列,设置固定样地,采集0~10、10~30、30~50、50~70 cm土层土壤样品,测定有机碳(SOC)、全氮(TN)、全磷(TP)、全钾(TK)、铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(-)-N)含量及碳氮比(C/N)和土壤pH,估算各演替序列下土壤碳氮储量,分析在自然恢复演替不同阶段的土壤碳氮含量与储量特征。[结果]植被自然恢复演替显著提高土壤SOC和TN含量与储量(P<0.001),灌乔阶段的土壤SOC和TN含量与储量最高,含量分别为57.75和6.31 g·kg^(-1),储量分别为87.71和10.06 t·hm^(-2),相比弃耕地阶段的碳氮储量分别增长51.88%和30.31%;各演替阶段0~30 cm土层SOC储量占0~70 cm土层的64.02%~73.68%,TN储量占64.73%~78.55%;0~70 cm土层C/N在自然恢复演替过程中呈先升后降的变化趋势,在灌丛阶段最高,为9.56;0~30 cm土层C/N在乔木阶段最高,为9.98,30~70 cm土层C/N相对较低;土壤NH_(4)^(+)-N储量以灌乔阶段最高(0.103 t·hm^(-2));土壤NO_(3)^(-)-N储量以弃耕地阶段最高(0.076 t·hm^(-2)),其次为灌乔阶段(0.038 t·hm^(-2));土壤SOC和TN储量与土壤NH_(4)^(+)-N、NO_(3)^(-)-N和TP含量显著正相关(P<0.05),此外,土壤SOC储量与土壤TN、TK含量显著正相关(P<0.05),土壤TN储量与土壤SOC含量显著正相关(P<0.05);土壤C/N与土壤SOC、TN和NH_(4)^(+)-N含量极显著正相关(P<0.01),与土壤TP含量显著正相关(P<0.05),与土壤TK含量极显著负相关(P<0.01)。[结论]西南喀斯特地区植被自然恢复演替可显著提高土壤碳氮含量与储量(P<0.001),对0~30 cm土层的碳氮含量与储量、C/N的影响比在30~70 cm土层更明显。土壤碳氮�【Objective】This study is aimed to investigate the variation characteristics of soil carbon and nitrogen storage of typical communities in the process of vegetation natural restoration succession,and provide data support for vegetation restoration and reconstruction in southwest karst area.【Method】By using the space-for-time substitution method,the natural restoration succession stages of abandoned cropland(abandoned cropland for half a year),grassland(5-10 a),shrub(15-25 a),shrub-forest(30-40 a)and forest(50-60 a)in karst trough valley of Zhongliang Mountain in Chongqing were selected as the research objects,permanent plots were established in each succession stages;the contents of soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP),total potassium(TK),ammonium nitrogen(NH_(4)^(+)-N),nitrate nitrogen(NO_(3)^(−)-N),soil carbon-nitrogen ratio(C/N)and soil pH in 0-10,10-30,30-50,50-70 cm were measured to estimate the soil carbon and nitrogen storage in each succession stage,and analyze the soil carbon and nitrogen content and storage characteristics in different stages of natural restoration succession.【Result】The natural vegetation restoration and succession significantly increased SOC and TN contents and storage(P<0.001),and the highest SOC and TN contents and storage were found in shrub-forest,with contents of 57.75 g·kg^(−1)and 6.31 g·kg^(−1)and storage of 87.71 t·hm^(−2)and 10.06 t·hm^(−2),respectively,which increased by 51.88%and 30.31%compared with the abandoned farmland stage.The SOC storage in 0-30 cm soil layer accounted for 64.02%-73.68%of the 0-70 cm soil layer,and the soil TN storage accounted for 64.73%-78.55%.The soil C/N in 0-70 cm soil layer increased first and then decreased during the natural vegetation restoration succession,and the soil C/N in shrubland stage was the highest,which was 9.56.The C/N ratio of forest stage in 0-30 cm soil layer was the highest,which was 9.98,and the C/N ratio of 30-70 cm soil layer was relatively low.Soil NH_(4)^(+)-N storage o

关 键 词：喀斯特地区 天然次生林 自然演替 碳氮 含量与储量 

分 类 号：S714.2[农业科学—林学]