黄河源区高寒草甸裸露斑块形成机理与生态修复关键限制因子  

Formation mechanism of alpine meadow bare patches and key factors limiting their restoration in the Source Zone of the Yellow River

作　　者：段成伟 李希来[1,2] 李成一[1,2] 杨鹏年 柴瑜 徐文印 DUAN Chengwei;LI Xilai;LI Chengyi;YANG Pengnian;CHAI Yu;XU Wenyin(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China;State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学农牧学院,西宁810016 [2]青海大学高原生态与农业国家重点实验室,西宁810016

出　　处：《生态学报》2024年第16期6952-6964,共13页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(U21A20191);青海省科学技术厅科技援青合作专项项目(2023⁃QY⁃210);高等学校学科创新引智计划(D18013);青海省科技创新创业团队项目“三江源生态演变与管理创新团队”。

摘　　要：为探讨黄河源区斑块化退化高寒草甸可持续恢复技术,通过野外调查和室内盆栽验证试验相结合的方法研究了黄河源区健康草甸和高原鼠兔(Ochotona curzoniae)引起的退化斑块土壤质地组成,以及室内盆栽植物地上生物量和土壤特征等关键因子的变化规律,阐明了黄河源区高寒草甸裸露斑块的形成机理与生态修复关键限制因子。结果表明:健康草甸主要由土壤颗粒、根系和石块三部分组成。各组分单位重量占比从大到小依次为土壤颗粒(0.65±0.013)、根系(0.11±0.003)和石块(0.02±0.001)。各组分单位体积占比从大到小依次为根系(0.62±0.003)、土壤颗粒(0.30±0.004)和石块(0.06±0.002)。不同退化斑块间土壤质地组成(砂粒、粉粒和黏粒)差异均不显著(P>0.05)。高寒草甸的破碎化,导致草甸根系死亡,斑块土壤颗粒自然沉降形成裸露斑块。室内花盆裸露斑块土壤镇压处理可显著提高植物地上生物量(P<0.05)。土壤湿度、蓄水量、容重、电导率、紧实度、粘聚力和根⁃土⁃石块复合体抗剪强度随花盆土壤镇压深度的增加而显著增加(P<0.05)。土壤水分是影响高原鼠兔扰动形成不同退化斑块生态修复的关键限制因子。裸露斑块通过镇压显著增加土壤蓄水量(P<0.05)。研究结果表明,人工撒施有机肥和补播牧草后,不同退化斑块生态修复有效镇压深度控制在10—15 cm,补播的禾本科牧草能顺利发芽并出苗,植物生长表现最好。In order to explore the optimal measures for restoring the degraded alpine meadows,a combination of field investigation and indoor potting experiments was carried out to investigate the composition and texture of differently degraded patches,and compare their differences and changes in aboveground biomass and soil properties in the Source Zone of the Yellow River.This study elucidates the formation mechanism of bare patches and identifies the key factors limiting the successful restoration of alpine meadow bare patches.The results show that healthy meadows comprised primarily soil particles,plant roots,and stony materials.The proportion(unit mass)of these components follows the descending order of soil particles(0.65±0.013),roots(0.11±0.003),and stones(0.02±0.001).In terms of the proportion of unit volume,the descending order of the three components changes to roots(0.62±0.003),soil particles(0.30±0.004),and stones(0.06±0.002).There is no significant difference in soil texture(sand,silt,and clay)among differently degraded patches(P>0.05).Fragmentation of alpine meadows results in the death of grass roots and the natural settling of fine soil particles to form bare patches.Mechanical compression of bare patch soil in indoor pots significantly increased plant aboveground biomass(P<0.05).Soil moisture,water storage,bulk density,conductivity,soil compaction,cohesion,and root⁃soil composite shear strength increased significantly with the increasing compression intensity(P<0.05).Soil moisture was identified as the key factor limiting the successful restoration of differently degraded alpine meadow patches formed by plateau pika(Ochotona curzoniae)disturbance.Bare patches′ability to retain soil moisture significantly increased after soil compression(P<0.05).The results of this study showed that the best strategies of restoring differently degraded bare patches were manually fertilizing the soil with organic fertilizers and seeding graminoid grasses,followed by the effective compression of the soil to a depth o

关 键 词：高寒草甸 斑块化退化 裸露斑块 土壤镇压 生态修复 

分 类 号：X171.4[环境科学与工程—环境科学]