西南地区森林NEP时空演变特征及其驱动因素  

Study on the spatial⁃temporal evolution characteristics and driving factors of forest NEP in Southwest China

作　　者：曹云 陈紫璇 莫建飞 孙应龙 延昊 CAO Yun;CHEN Zixuan;MO Jianfei;SUN Yinglong;YAN Hao(National Meteorological Center,China Meterological Administration Hydro-Meteorology key Laboratory,Beijing 100081,China;Guangxi Institute of Meteorological Sciences,Nanning 530022,China)

机构地区：[1]国家气象中心、中国气象局水文气象重点开放实验室,北京100081 [2]广西壮族自治区气象科学研究所,南宁530022

出　　处：《生态学报》2025年第7期3252-3266,共15页Acta Ecologica Sinica

基　　金：中国气象局水文气象重点开放实验室开放研究课题(23SWQXZ015);中国气象局创新发展专项(CXFZ2024J052);广西重点研发计划(桂科AB23026052)。

摘　　要：作为我国第二大林区,西南林区生态环境脆弱、气候变化敏感,特别是近年来受气候、环境等因素影响,林区固碳功能已出现变化,引起了广泛关注。因此,在气候变化背景下开展西南林区固碳能力的时空动态演变及其驱动影响研究具有重要意义。采用陆地生态系统碳通量模型和土壤呼吸模型,结合气象和遥感资料,对2001—2021年西南林区净生态系统生产力(Net Ecosystem Productivity, NEP)进行评估。采用Theil-Sen趋势分析、Mann-Kendall趋势检验和Hurst指数,分析西南林区NEP变化的趋势特征与可持续性特征;基于偏相关性分析和地理探测器模型等方法,定量评估气温、降水、坡向坡度等气候环境因子对森林NEP的影响程度。结果表明:(1)西南林区多年平均NEP为333.8 g C m^(-2)a^(-1)(3.338 t C hm^(-2)a^(-1)),总体表现为碳汇,且2001—2021年林区NEP呈现波动增长趋势,平均每年增加3.9 g C m^(-2)a^(-1)(0.039 t C hm^(-2)a^(-1))。其中,NEP达到显著增加趋势的面积,占林区总面积的33.2%,主要分布在四川北部、云南西南部等地。落叶阔叶林和贵州林区NEP增加趋势最大,平均每年分别增加4.5 g C m^(-2)a^(-1)(0.045 t C hm^(-2)a^(-1))和5.9 g C m^(-2)a^(-1)(0.059 t C hm^(-2)a^(-1))。(2)从变化持续性看,大部林区NEP的Hurst指数小于0.5,表明NEP未来变化趋势与过去相反,林区NEP未来可能呈下降趋势,其中NEP由增加趋势变为减少趋势的林区面积占比达到64.6%。但是依然有30.5%林区NEP未来变化呈增加趋势,其中云南林区分布最多(57.1%)、四川次之(36.2%)。(3)从时间尺度的影响分析来看,近20年西南大部林区NEP与降水具有负相关性、与蒸散和气温具有正相关性,其中蒸散是影响林区NEP的第一关键气候因子,影响面积占比67.2%,降水影响范围次之(21.3%),气温影响范围第三(6.1%)。但是关键气候因子在不同森林类型间存在一定差异,其中降水是影响贵州灌丛和�As the second largest forest region in China,the ecological environment of the southwest forest area is fragile and highly sensitive to climate change.In recent years,forest carbon sequestration has undergone changes and has attracted significant attention due to the impact of climate and environmental factors.Thus,studying the spatiotemporal dynamics and influencing factors of carbon sequestration capacity in southwest China′s forests against the backdrop of climate change is significant.By using the soil respiration model and the Terrestrial Ecosystem Carbon flux(TEC)model,combined with meteorological and remote sensing data,we estimated the net ecosystem productivity(NEP)in the forest of southwest China from 2001 to 2021.And trends in NEP variation and its sustainability were analyzed using Theil⁃Sen slope estimation,Mann⁃Kendall mutation test,and Hurst index.Furthermore,methods including partial correlation analysis,geographical detectors,etc.were employed to quantitatively evaluate the influence of climate and environmental factors such as temperature,precipitation,aspect,and slope on forest NEP.The results indicated that:(1)The average annual NEP in the forest of southwest China was 333.8 g C m^(-2) a^(-1)(3.338 t C hm^(-2) a^(-1)),indicating an overall carbon sink.From 2001 to 2021,forest NEP in southwest China showed a fluctuating growth trend,increasing by an average of 3.9 g C m^(-2) a^(-1)(0.039 t C hm^(-2) a^(-1))annually.Areas with a significantly increasing NEP trend accounted for 33.2%of the total forest area,predominantly in northern Sichuan and southwest Yunnan.Deciduous broad-leaved forest and forest areas in Guizhou province showed the highest NEP increases,averaging 4.5 g C m^(-2) a^(-1)(0.045 t C hm^(-2) a^(-1))and 5.9 g C m^(-2) a^(-1)(0.059 t C hm^(-2) a^(-1))per year,respectively.(2)From the perspective of change persistence,the Hurst index of NEP in most forest areas was less than 0.5,indicating that future NEP trends might reverse the past patterns.Forest NEP in southwest China is

关 键 词：净生态系统生产力 气候变化 时空变化 变化趋势 驱动因素 西南林区 

分 类 号：S718.5[农业科学—林学]