坡向对道路边坡生物土壤结皮组成和发育特征的影响  

Influence of slope aspect on the composition and development characteristics of biological soil crusts on roadside slopes

作　　者：张鑫钰 何萍[1,2,3,4] 徐杰 ZHANG Xinyu;HE Ping;XU Jie(Institute of Ecology,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;State Environment Protection Key Laboratory of Regional Eco-Process and Function Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;State Key Laboratory of Environment Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;National Joint Research Center for Ecological Conservation and High Quality Development of the Yellow River Basin,Beijing 100012,China)

机构地区：[1]中国环境科学研究院生态研究所,北京100012 [2]中国环境科学研究院国家环境保护区域生态过程与功能评估重点实验室,北京100012 [3]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012 [4]国家黄河流域生态保护和高质量发展联合研究中心,北京100012

出　　处：《生态学报》2024年第19期8459-8468,共10页Acta Ecologica Sinica

基　　金：黄河流域生态保护和高质量发展联合研究(第一期)黄河流域生态监测网络构建与生态质量评估项目(2022-YRUC-01-0101-02-01)。

摘　　要：坡向是影响温带干旱半干旱区生物土壤结皮生长的关键因素,但是以往研究对坡向的划分比较简单粗略。陕西省榆林市横山区一处具有360°坡向的道路边坡上自然生长着生物土壤结皮,以15°坡向为间隔,研究该道路边坡不同坡向生物土壤结皮组成(藓、藻结皮分盖度)、发育特征指标(结皮厚度、苔藓株高、生物土壤结皮叶绿素a含量)、结皮层含水率和抗剪强度的差异以及成因。结果表明:(1)在南北向上,315°—30°区间内的混合生物结皮以藓结皮为主、藻结皮次之;75°—225°区间内的混合生物结皮以藻结皮为主、藓结皮次之。(2)在东西向上,生物土壤结皮的组成和发育呈现非对称性。混合生物结皮中藓结皮分盖度、结皮层含水率和生物土壤结皮叶绿素a含量在西向(225°—315°)平均分别是东向(45°—135°)的3.31、2.82倍和2.55倍,发育程度总体表现为西向优于东向。(3)当以藻结皮为主时,结皮层含水率低于3.8%,以藓结皮为主时,结皮层含水率高于7%。提出了道路边坡生物土壤结皮在不同方向上组成和发育特征的差异性规律和可能的成因,有助于生物土壤结皮生态修复工程中不同方向上藻、藓的精准配置。Slope aspect is a major factor influencing biological soil crusts in arid and semi-arid areas.The majority of previous studies on slope aspect classification were relatively rough.It is still unclear how 360°continuous slope aspects affect biological soil crusts on roadside slopes.To explore the differentiation mechanism of biological soil crusts on different slope aspects and summarize their distribution,a roadside slope with 360°slope aspects in Hengshan District,Yulin City,Shaanxi Province,was taken as the research site.The road construction time,soil matrix,slope gradient and other background conditions were all the same.Biological soil crusts on the roadside slopes developed naturally.Based on this outstanding natural experimental site,the differences and causes of mixed biocrusts composition(moss and cyanobacterial crust coverage),developmental characteristic indicators(biocrust thickness,moss height,and chlorophyll a content of mixed biocrusts),water content of biocrusts and soil surface,and shear strength of biocrusts were studied at 15°slope intervals.The results showed that:(1)In the north-south direction,the mixed biocrusts in the 315°—30°range were dominated by moss crust,followed by cyanobacterial crust,while those in the 75°—225°range were dominated by cyanobacterial crust,followed by moss crust.Moss and cyanobacterial crust coverage along continuous slope aspects demonstrated a trade-off relationship.(2)In the east-west direction,the composition and development of mixed biocrusts exhibited an asymmetrical distribution pattern.Moss coverage of mixed biocrusts,water content of biocrusts and soil surface,and chlorophyll a content of mixed biocrusts were 3.31,2.82,and 2.55 times higher on the western slope(225°—315°)than on the eastern slope(45°—135°),indicating better development on the western slope.(3)The water content of biocrusts and soil surface was related to the ratio of moss crust coverage and cyanobacterial crust coverage in mixed biocrusts.The water content of biocrusts an

关 键 词：生物土壤结皮 道路边坡 结皮层含水率 叶绿素A含量 坡向 自然实验 

分 类 号：S154[农业科学—土壤学]