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【目的】森林生物量大小与森林生产力水平的高低密切相关,是反映森林生态系统功能的基本数据。【方法】以河南省西峡县为研究区域,以研究区1993—2013年5期森林资源连续清查固定样地数据,1993年、1998年、2003年、2008年、2013年Landsat TM/ETM+/OLI遥感图像为主要信息源,通过建立4种遥感估测模型,对研究区域1993—2013年的森林地上部分生物量进行时空动态分析。【结果】(1)随机森林遥感估测模型综合性能最高,k最邻近算法与装袋算法居中,多元线性回归最低;(2)海拔、坡度、亮度指数、湿度指数、垂直植被指数和有效叶面积指数这6个因子是影响研究区域森林地上部分生物量大小的重要环境因子;(3)1993—2013年期间,研究区域单位面积森林生物量经历了先从1993年34.68 Mg/hm2下降到2003年32.59 Mg/hm2、然后上升到2013年44.65 Mg/hm2的复杂变化历程;(4)1993—2013年期间,表征空间自相关程度的全局Moran’I指数不断降低,表明研究区域森林地上部分生物量的空间聚集性呈持续下降趋势。【结论】乱砍滥伐、毁林开荒行为,退耕还林、天然林保护政策,以及生态廊道、村镇绿化工程建设,是研究区森林地上生物量发生时空变化的主要驱动因素。
【Objective】 The size of forest biomass is closely related to the level of forest productivity, which is the basic data reflecting the function of forest ecosystem. 【Method】 With Xixia County of Henan Province as the research area and the fixed area data of five consecutive forest resources from 1993 to 2013 in the research area, Landsat TM / ETM + / OLI remote sensing images as the main source of information, through the establishment of four kinds of remote sensing estimation model, spatial and temporal dynamic analysis of aboveground biomass in the study area from 1993 to 2013. 【Result】 (1) The comprehensive performance of the random forest remote sensing estimation model is the highest, the k nearest neighbor algorithm and the bagging algorithm are in the middle and the multiple linear regression is the lowest. (2) The elevation, slope, brightness index, humidity index, vertical vegetation index (3) From 1993 to 2013, the forest biomass per unit area of the study area experienced the first decrease from 34.68 Mg / hm2 in 1993 to the third in 2003 (32.59 Mg / hm2) and then increased to 44.65 Mg / hm2 in 2013. (4) The global Moran’I index, which characterizes the degree of spatial autocorrelation, decreased continuously from 1993 to 2013, indicating that the aboveground biomass The amount of spatial aggregation showed a downward trend. 【Conclusion】 Deforestation, deforestation and wasteland reclamation, the policy of returning farmland to forest and natural forest protection, as well as the construction of ecological corridor and village afforestation project are the main driving forces for temporal and spatial changes of biomass of forest land in the study area.