珠三角地区城镇绿道森林景观特征

绿道是城市绿地系统的重要组成部分。通过调查研究珠三角地区的都市绿道类型、郊野绿道类型、生态绿道类型等3种类型绿道，设立了302个样方，对乔木、灌木和地被进行了详细调查，并对其空间结构、郁闭度和盖度以及配植模式进行分析比较，得出以下结论:①3种类型绿道采用乔+灌+草的复层结构形式显著高于其他结构，其所占比例都市型（79.8%） > 郊野型（60.7%） > 生态型（45.7%）。②都市型绿道的乔木郁闭度显著高于生态型绿道，相对郁闭程度都市型（0.066） > 郊野型（0.040） > 生态型（0.026）。3种类型绿道的乔木、灌木和地被的总体覆盖程度没有显著差异，相对盖度生态型（0.068） > 都市型（0.067） > 郊野型（0.060）。③绿道乔木的配置模式，列植模式出现的比例显著高于其他模式，占65.6%；绿道灌木的配置模式，列植、丛植的模式在绿道中出现的比例显著高于其他模式，列植占52.0%，丛植占31.5%；绿道地被植物的配置模式，单一式的地被植物配置模式显著高于其他模式，所占比例为64.6%。

Landscape features of urban forest greenbelts in the Pearl River Delta

Greenbelts are an important part of the urban green space system. To understand the features of urban forest greenbelts, with the help of the GPS, a 400 m2 standard sample was set along the greenbelt every 5 km. There were 302 greenbelt sample plots in the Pearl River Delta (PRD) were tested and analyzed by vegetative spatial structure (tree-shrub-grass), canopy density, canopy coverage, and plant configuration according to three types (urban, suburban, and ecological). Results showed that the proportion of tree-shrub-grass structure was the greatest with the proportion of the three types of greenbelts being urban (79.8%) > suburban (60.7%) > ecological (45.7%). The canopy density of the urban greenbelt was the greatest with relative canopy densities being urban (0.066) > suburban (0.040) > ecological (0.026). Coverage of the three types of greenbelts were almost same with their relative coverage being ecological (0.068) > urban (0.067) > suburban (0.060). The linear planting (65.6%) was the most common planting scheme for trees. The linear planting (52.0%) and group planting (31.5%) was the most common planting scheme for shrubs. The single species of ground cover (64.6%) was the most common planting scheme for grasses.