泥石流频发流域失稳性坡面植物群落特征及生态系统碳储量  

Plant Community and Ecosystem Carbon Stocks in the Unstable Slopes Subjected to High-Frequency Debris Flow

作　　者：杨柳生 高若允 孙凡[1,2,3] 吉盆 林勇明 YANG Liusheng;GAO Ruoyun;SUN Fan;JI Pen;LIN Yongming(College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China;Key Laboratory of Mountain Hazards and Surface Processes, Institute of mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Conservancy, Chengdu 610041, China;Key Laboratory for Forest Ecosystem Process and Management of Fujian Province, Fuzhou 350002, China)

机构地区：[1]福建农林大学林学院,福州350002 [2]中国科学院、水利部成都山地灾害与环境研究所山地灾害与地表过程重点实验室,成都610041 [3]福建省高校森林生态系统过程与经营重点实验室,福州350002

出　　处：《山地学报》2022年第3期355-368,共14页Mountain Research

基　　金：国家自然科学基金(42071132);中国科学院山地灾害与地表过程重点实验室开放基金(20190402);福建农林大学杰出青年科研人才计划项目(xjq2017016)。

摘　　要：植物群落的更替发展改变其生境特征、群落内部的生活状况,影响着陆地生态系统的碳循环和碳平衡。针对植物群落变化过程与碳储量分布间耦合关系,以及灾害频发区生态系统的固碳能力、碳源汇识别等方面的科学认知并不充分,当前无法完全理解灾害干扰形成的失稳性坡面上植物群落特征变化对生态系统碳储量的影响机制。本文以蒋家沟流域不同垂直气候带失稳性坡面各区段(稳定区、失稳区和堆积区)植物群落为研究对象,通过野外植被调查和室内试验,对群落差异及生态系统碳储量间的关系进行综合分析。结果表明:(1)植物物种数和Margalef多样性指数随坡面区段向下呈逐渐增加的趋势,而植被盖度则逐渐减少,这与堆积区缺乏明显的优势物种有关。(2)各坡面不同区段均以多年生植物占优势,禾本科和菊科植物分布广但仅在干热河谷区占较高优势;从稳定区到堆积区,全流域不同生活型的植物重要值表现为:一年生植物和菊科植物逐渐增大,多年生植物和禾本科植物先增后减,其他科植物则先减后增。(3)各坡面植被碳储量均表现为稳定区显著高于失稳区和堆积区(P<0.05),除多照沟阳坡外,土壤碳储量与生态系统碳储量均表现为稳定区显著高于堆积区(P<0.05)。(4)植被盖度、凋落物生物量均与生态系统碳储量呈显著正相关(P<0.05),而一年生草本植物重要值与生态系统碳储量呈极显著负相关(P<0.01),表明植被盖度高且受灾害干扰较少的稳定区植物群落固碳能力高于堆积区。本研究分析山地灾害频发区坡面植被群落结构和多样性与生态系统碳储量关系,可为植物措施的合理配置、生态修复及固碳管理等提供科学依据。The successional development of plant communities changes their habitat characteristics and living conditions,playing an important role in the carbon cycle and carbon balance of terrestrial ecosystems.There is insufficient scientific understanding of the coupling relationships between plant community change process and carbon stock distribution,the carbon sequestration capacity and the identification of carbon source or sink in the disaster-affected ecosystems.As a result,the influencing mechanism of changes in plant community distributing on unstable slopes caused by disaster disturbances on ecosystem carbon stock is still poorly understood.In this study,vegetation ecosystem on different sections(downward as stable area,unstable area and deposition area)of unstable slopes in different climatic regions of the Jiangjia Gully in China,were selected to investigate community characteristics and their relationships with carbon stocks.The results showed that:(1)The number of plant species and Margalef diversity index gradually increased with the slope downward,whereas vegetation coverage decreased due to the lack of dominant species in the deposition area.(2)Perennials dominated in different sections of all unstable slopes,whereas Gramineae and Compositae distributed widely but dominated only in dry-hot valley region.On all slopes,from top(stable area)to bottom(deposition area),the important values of plants in the whole watershed showed as follows:annual plants and Compositae increased;perennial plants and Gramineae increased first and then decreased;and other families decreased first and then increased.(3)Among all slopes,vegetation carbon stock in stable area was significantly higher than that in unstable area and deposition area(P<0.05).Except Duozhaogou sunny slope,soil carbon and ecosystem stocks of all slopes were significantly higher in stable area than in deposition area(P<0.05).(4)Vegetation coverage and litter biomass were significantly positively correlated with ecosystem carbon stocks(P<0.05),whereas the i

关 键 词：群落特征 碳储量 失稳性坡面 区段 植物多样性 蒋家沟 

分 类 号：S718.55[农业科学—林学]