北京城市绿地系统景观多样性分析

城市绿地系统景观多样性是城市景观生态系统研究的重要内容. 运用景观生态学的原理，在GIS支持下对北京五环内城市绿地景观斑块的等级与分布、空间结 构的度量进行了研究和分析，并对该市的城市绿地景观按城市梯度进行了综合评价. 研究结 果表明，北京五环内城市绿地斑块18 470个，绿地面积11 023.29 hm2，斑块数以面积小于3 000 m2的中小型斑块为主，占总数的72%，绿地面积以面积大于3 000 m2的大 中型和大型斑块为主，占总面积的86.64%；北京五环内城市绿地斑块密度为167.6个/km 2，边缘密度为2.58 m/hm2，景观多样性指数为1.32，均匀度为0.82；城市绿地景观格局沿城市梯度呈一定的规律性变化，总体表现为人类活动干扰增强，绿地景观破碎化加剧，景观多样性降低，分布较为均匀，整体绿地景观受面积影响较大；主要景观类型之间景观特征差异明显，随着人类干扰的增强，景观类型斑块边缘密度加大，破碎化严重. 平均斑块面积公园绿地最高，斑块密度附属绿地最高，斑块形状附属绿地最为复杂，斑块的聚集程度以公园绿地最高. 

Landscape diversity of urban greenland system in Beijing.

Landscape diversity of urban greenland system is a key matter of the study of landscape ecosystem in a city.By using landscape ecology theory,under the support of GIS,the rank,distribution and space structural measurement of urban greenland patches within the 5th ring road of Beijing were analyzed,and an integrated evaluation of the urban greenland landscape along the city gradient was carried out.The results show that there are 18 470 patches of green space within the 5th ring road,covering an area of 11 023.29 hm~2.72% of the patches are middle and small size.However,86.64% of the total area is made up of middle-large and large patches,whose areas are more than 3 000 m~2.The patch density is 167.6 ones/km~2,edge density is 2.58 m/hm~2,landscape diversity index is 1.32 and landscape evenness index is 0.82.The urban greenland landscape structure shows regular difference with the urban gradient.Overall,it manifests that with increasing human activity disturbance,accelerating landscape fragmentation and less landscape diversity,the whole landscape is controlled by a few landscapes.Acreage exerts a great impact on the whole landscape,which is well-distributed.Landscape characteristics vary greatly among the major types of landscape.With increasing human disturbance,the edge density of landscape genre is growing and fragmentating.The average patch area of the park green space is the highest,while the affiliated green space has the highest patch density and the highest complexity.Still,the park green space has the highest assembly degree.