北京市域乡村人居林树冠覆盖及其区域差异分析

乡村人居林建设是落实新农村建设、实施乡村振兴战略和振兴农村生态文明的重要举措。以北京市为对象,基于北京市域2017年0.5m分辨率航空影像与2017年1：10万土地利用（LUCC）图等基础资源,在全市范围内随机选择260个行政村,从研究区域内乡村人居林树冠覆盖率、功能类型、斑块等级和景观格局特征四个层面展开区域差异特征分析。研究结果显示,北京市整体乡村人居林树冠覆盖率为18.32%,其中平原区和山区分别为18.40%和17.83%。在平原区范围内,乡村人居林树冠覆盖率呈近郊区（21.70%） > 远郊区（13.87%） > 延庆盆地区域（16.34%）;在山区内部,乡村人居林树冠覆盖率呈现低山区（24.45%） > 浅山区（16.55%） > 深山区（12.41%）,太行山区（20.98%） > 燕山区（14.11%）。在乡村人居林功能类型分布中,片林为各分区最主要类型,在平原区和山区中分别占比55.75%和57.15%。在斑块等级结构方面,乡村人居林斑块总体呈现小而分散的特点,其中小斑块数目在区域中占比达93.03%,而各等级斑块在规模大小方面呈现"平分秋色"的特点。就景观格局指数特点而言,平原区内近郊区,山区内的深山区和燕山区乡村人居林斑块复杂程度、受人为干扰强度和多样性更高。综上特征,究其动因,农村居民点聚落规模、集聚形式和建设类型以及森林资源本底是影响乡村人居林建设条件的重要原因。

Village human habitat forest canopy coverage and regional difference analysis in Beijing

Construction of village human habitat forest is an important initiative to implement the new rural construction, the rural revitalization strategy and the rural ecological civilization. On the basis of resources such as remote sensing image with 0.5 resolution and 1:10 ⁵ LUCC map in 2017, 260 sample villages were selected randomly in Beijing. Then, the differences in canopy coverage, functional types, patch structure and landscape pattern of village human habitat forest in different districts were analyzed. The results showed that, the canopy coverage of village human habitat forest was 18.32% in the whole city, 17.40% in the plain area and 17.83% in the mountain area, respectively. In the plain area, the canopy coverage of village human habitat forest showed suburban area (21.70%) > outer suburban area (13.87%) > Yanqing basin area (16.34%). In the mountain area, the canopy coverage of village human habitat forest showed low mountain area (24.45%) > shallow mountain area (16.55%) > deep mountain area (12.41%), and the canopy coverage of village human habitat forest showed Taihang mountain area (20.98%) > Yan mountain area (14.11%). In the distribution of village human habitat forest types, the most important type in each district is patch forest, accounting for 55.75% in the plain area and 57.15% in the mountain area. In terms of the distribution of patch structure, the overall characteristic was small and scattered, the number of small patches accounted for 93.03% in Beijing, while there was no significant difference in the area of each grade of patches. In terms of the characteristic of landscape pattern index, patch complexity, intensity and diversity of human disturbance were more intense in the suburban area, the deep mountain area and the Yanshan mountain area. The main factors influencing the construction conditions of village human habitat forest are the scale, agglomeration form and construction type of the rural residential area and the background abundance of forest resources.