扬州瘦西湖公园绿地空间格局与结构的量化研究

Quantitative analysis of urban green-land structure: A case study on Slender West Lake

采用遥感图像判读和野外调查相结合的方法,定量分析扬州瘦西湖公园绿地的空间格局及植物群落的物种结构。结果表明:扬州瘦西湖公园共有绿地斑块230个,而斑块形状指数Ips≥1.50的绿地斑块为105个,绿地斑块形状受人为干扰程度较大。绿地景观类型较多,多样性指数较高。植被的生长状况良好;物种丰富,其中垂柳、桃、意杨、枫杨在树木株数和相对优势度上均占优势;植被在高度和胸径上的分布均表现为具有向上发展的潜力,属于发挥生态效益的最佳时期。扬州瘦西湖公园的树种多度与基于叶面积的相对优势度之间无明显关联,数量上占优势的树种,其相对优势度不一定很高。植被树木株数与不同树高等级间的分布关系表现为随着树木高度级的增加,树木株数相应减少;树木株数分布与不同胸径等级间的关系也呈现类似的情况。

The spatial features and attribute data of urban forests in Slender West Lake were acquired by using satellite photographs and field investigation. Through selecting the indices such as patch size, patch shape index, fractal dimension, diversity and dominance index, etc. , the landscape pattern was analyzed and the following results were achieved： ① the number of the patches in the researching area was 230, while in 105 patches the patch shape index was large than 1.5. ② the type of the landscape was rich, and the diverslty index was high. And after systemic and quantitative analysis of the species composition and spatial distribution pattern of urban forest community based on geographic information system （GIS）, the following results were achieved：①the vegetation in the park was rich and in a good condition. Saliz babylonica, Prunus persica, Populus euramevicana ＂I-214＂ and Pterocarya stenoptera were the main species according to their abundant individuals and relative dominance. The spatial distribution pattern of this vegetation indicated that it was in a growing level and in the best state for ecological benefits;② the tree species relative dominance based on vegetation quantity had no distinct relationship with the species abundance, and the species having abundant individuals might have a low relative dominance; and ③ the curve displayed in the relationship diagram between tree individuals and tree height showed descending. With the increment of tree height class, the relationship between tree individuals and tree diameter at the breast height （DBH） showed the same result.