还林树种对紫色土团聚体分布和稳定性的影响  

Effect of Reforestation Tree Species on the Distribution and Stability of Purple Soil Aggregates

作　　者：钟宇健 何烽 韩光中[2] 赵霞 杨帆 ZHONG Yujian;HE Feng;HAN Guangzhong;ZHAO Xia;YANG Fan(Qinghai Provincial Key Laboratory of Physical Geography and Environmental Process,College of Geographical Science,Qinghai Normal University,Xining 810008,China;Engineering Technology Center for Soil Process Simulation and Pollution Remediation in Neijiang City,College of Geography and Resources Science,Neijiang Normal University,Neijiang,Sichuan 641100,China;Academy of Plateau Science and Sustainability-Plateau Soil Information Science Research Team,People’s Government of Qinghai Province,Xining 810008,China)

机构地区：[1]青海师范大学地理科学学院青海省自然地理与环境过程重点实验室,西宁810008 [2]内江师范学院地理与资源科学学院内江市土壤过程模拟与污染修复工程技术研究中心,四川内江641100 [3]青海省人民政府北京师范大学高原科学与可持续发展研究院—高原土壤信息科学研究团队,西宁810008

出　　处：《水土保持学报》2024年第6期284-292,301,共10页Journal of Soil and Water Conservation

基　　金：内江师范学院科研启动费项目(18B10);科技基础资源调查专项(2022FY100202);国家级大学生创新创业训练计划项目(X2021009);第二次青藏高原综合考察研究项目(2019QZKK0306)。

摘　　要：[目的]退耕还林是改善土壤结构、减少水土流失的重要举措,明确还林树种对土壤团聚体形成过程的影响机制可为水土保持提供重要的依据。[方法]选择华西雨屏区紫色土坡耕地(玉米地)还林20年形成的柳杉林、混交林、茶园和慈竹林4种人工林土壤为研究对象,分析土壤团聚体分布及其稳定性的变化。[结果](1)相较于坡耕地,混交林、茶园和慈竹林土壤>5 mm团聚体含量显著增加,而0.5~1 mm团聚体含量显著减少(p<0.05),优势团聚体由0.5~1 mm转变为>5 mm;(2)人工林土壤团聚体GMD、MWD和R 0.25分别上升46.93%~330.30%,47.01%~191.03%和5.02%~19.66%,而PAD_(0.25)和PSD分别下降15.41%~75.09%和1.65%~9.20%,表明人工林土壤团聚体稳定性增强,具体表现为茶园>慈竹林>混交林>柳杉林,以茶园和慈竹林较优;(3)土壤优势团聚体含量及其稳定性与惰性有机碳含量呈极显著正相关,而与土壤砾石含量呈极显著负相关(p<0.01)。[结论]林木生长促进紫色土风化,为土壤团聚体形成提供物质基础;人工林土壤形成的腐殖质作为胶结物质,促进大团聚体的形成及其稳定性的维持。[Objective]Afforestation following the Grain for Green initiative is a crucial measure to improve soil structure and reduce soil erosion.Understanding the mechanisms of the effects of afforestation tree species on the formation of soil aggregates can provide valuable insights for soil conservation.[Method]Four types of artificial forests(Cryptomeria fortunei(CF),Cryptomeria fortunei and Betula luminifera(MF),Camellia sinensis(CS),and Neosinocalamus affinis(NA))established on sloping farmland(SF)(cornfield)in the Rainy Area of Western China after 20 years of afforestation were taken as the research objects,in order to analyze the changes in soil aggregate content and stability after the conversion from farmland to artificial forests.[Results](1)Compared to the sloping farmland,the artificial forests of MF,CS,and NA significantly increased the soil aggregates>5 mm,but decreasd the 0.5~1 mm soil aggregates(p<0.05).The dominant soil aggregates shifted from 0.5~1 mm to>5 mm.(2)The soil aggregate parameters,including the geometric mean diameter(GMD),mean weight diameter(MWD),and the content of aggregates of>0.25 mm(R 0.25),increased by 46.93%~330.30%,47.01%~191.03%and 5.02%~19.66%,respectively,in the artificial forests.Conversely,the destruction rate(PAD_(0.25))and fractal dimension(PSD)decreased by 15.41%~75.09%and 1.65%~9.20%,respectively.These indicators of aggregate stability consistently demonstrated that the stability of soil aggregates in the artificial forests was enhanced,with a specific ranking of CS>NA>MF>CF,indicating that CS and NA were both relatively superior.(3)The content and stability of dominant soil aggregates were extremely significantly positively correlated with the content of NOC,and extremely significantly negatively correlated with the content of soil gravel(p<0.01).[Conclusion]The weathering of purple soil following afforestation provides the material foundation for aggregate formation,while the humus formed in the soil of artificial forests acts as a binding agent,promoting the formation of

关 键 词：土壤结构 退耕还林 树种 土壤团聚体 华西雨屏区 

分 类 号：S152.4[农业科学—土壤学] S714.2[农业科学—农业基础科学]