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应用生态学报 ›› 2021, Vol. 32 ›› Issue (4): 1175-1183.doi: 10.13287/j.1001-9332.202104.002

• 研究论文 • 上一篇    下一篇

基于地理加权回归拓展模型的天然次生林碳储量空间分布

陈科屹1, 张会儒2*, 张博3, 何友均1   

  1. 1中国林业科学研究院林业科技信息研究所, 北京 100091;
    2中国林业科学研究院资源信息研究所, 北京 100091;
    3北京林业大学森林资源和环境管理国家林业局重点实验室, 北京 100083
  • 收稿日期:2020-06-03 接受日期:2020-07-26 发布日期:2021-10-25
  • 通讯作者: *E-mail: huiru@caf.ac.cn
  • 作者简介:陈科屹, 男, 1989年生, 助理研究员。主要从事森林可持续经营理论与技术研究。E-mail: lowrychen@sina.com
  • 基金资助:
    国家重点研发计划项目(2017YFC0504101)资助

Spatial distribution of carbon storage in natural secondary forest based on geographically weighted regression expansion model.

CHEN Ke-yi1, ZHANG Hui-ru2*, ZHANG Bo3, HE You-jun1   

  1. 1Research Institute of Forestry Policy and Information, Chinese Academy of Forestry, Beijing 100091, China;
    2Research Institute of Forest Resources Information Techniques, Chinese Academy of Forestry, Beijing 100091, China;
    3State Forestry Administration Key Laboratory of Forest Resources and Environmental Management, Beijing Forestry University, Beijing 100083, China
  • Received:2020-06-03 Accepted:2020-07-26 Published:2021-10-25
  • Contact: *E-mail: huiru@caf.ac.cn
  • Supported by:
    National Key R&D Program of China (2017YFC0504101).

摘要: 为精准获取区域尺度天然次生林的碳储量及其空间分布格局,以吉林省汪清林业局浪溪林场的天然次生林为研究对象,基于165块局级固定样地,以林分因子、地形因子和土壤因子为影响因子,将普通地理加权回归模型(GWR)作为基础,从空间维度、参数异质性特征和残差空间自相关性3个方面进行改进,构建7类拓展模型,即地理海拔加权回归模型(GAWR)、半参数地理加权回归模型(SGWR)、半参数地理海拔加权回归模型(SGAWR)、地理加权回归克里格模型(GWRK)、地理海拔加权回归克里格模型(GAWRK)、半参数地理加权回归克里格模型(SGWRK)和半参数地理海拔加权回归克里格模型(SGAWRK)。运用7类拓展模型对研究区的森林碳储量及其分布情况进行模拟估测,采用决定系数(R2)、均方误差(MSE)和赤池信息准则(AIC)对各种模型的拟合效果进行评价;最后,运用最优回归模型的拟合结果绘制森林碳储量空间分布图,分析研究区森林碳储量的分布规律。结果表明: 林分因子和地形因子对天然次生林碳储量产生了较大的影响,其中林分平均胸径是影响最大的变量,两者呈显著正相关;SGWR和SGAWR模型能够进一步降低GWR模型残差的空间自相关性;地理加权回归拓展模型能进一步提升GWR模型的拟合效果。其中,SGWRK模型具有最高的R2和最低的MSE和AIC。将海拔作为空间权重未能有效提高模型的拟合效果;浪溪林场森林总碳储量为205×104 t,碳密度为8.56~145.74 t·hm-2,平均值57.98 t·hm-2,整体上呈现西北高、东南低,边缘高、内部低的分布格局。通过改进地理加权回归基础模型对参数异质性特征和残差空间自相关性的处理,可以更好地揭示研究区森林碳储量与相关变量间的空间关系,提升模型对区域尺度森林碳储量及其空间分布的估测精度。

关键词: 天然次生林, 碳储量, 地理加权, 拓展模型, 空间分布

Abstract: To accurately assess carbon storage and its spatial distribution in natural secondary forest at the regional scale, we constructed seven expansion models by modifying the geographically weighted regression (GWR) in aspects of spatial dimension, parameter heterogeneity and residual spatial autocorrelation, based on data collected from 165 bureau level permanent plots in Langxi Forest Farm of Wangqing Forestry Bureau in Jilin Province. Stand factor, topography factor, and soil factor were selected as the influencing factors. The expansion models included geographically and altitudinal weighted regression (GAWR), semiparametric geographically weighted regression (SGWR), semiparametric geographically and altitudinal weighted regression (SGAWR), geographically weighted regression Kriging (GWRK), geographically and altitudinal weighted regression Kriging (GAWRK), semiparametric geographically weighted regression Kriging (SGWRK), and semiparametric geographically and altitudinal weighted regression Kriging (SGAWRK). Coefficient of determination (R2), mean square error (MSE) and Akaike’s Information Criterion (AIC) were used to evaluate the fitness of these models. Finally, the spatial distribution diagram of forest carbon storage was drawn with the fitting results of the optimal regression model, and the distribution pattern of forest carbon storage in the research area was analyzed. The stand factor and topographic factor had strong influence on carbon storage of natural secondary forests, among which the average diameter at breast height (DBH) of stands was the dominant variable. There was positive correlation between stand factor and topographic factor. SGWR and SGAWR model could reduce the spatial autocorrelation of the GWR model residual. The geographically regression expansion model could improve the fitting effect of GWR model. Among them, the SGWRK model had the highest R2 and the lowest MSE and AIC. The method with altitude as the spatial weight did not effectively improve the fitting effect of the model. The total forest carbon storage of Langxi Forest Farm was 205×104 t, and the carbon density ranged from 8.56 to 145.74 t·hm-2, with a mean value of 57.98 t·hm-2. Overall, the distribution pattern of carbon storage was high in the northwest and low in the southeast, while high in the edge and low in the interior. By improving the parameter heterogeneity and residual spatial autocorrelation in the GWR model, we can accurately assess the spatial relationship between forest carbon storage and relevant variables in the study area, and improve the estimation accuracy of the forest carbon storage and its spatial distribution at the regional scale.

Key words: natural secondary forest, carbon storage, geographically weighted, expansion model, spatial distribution