引入城市扩张干扰效应的生态服务价值化方法改进

城市扩张在规模上对自然环境空间造成挤压,在结构上加剧生境破碎化程度,且对其邻域的生态用地有负面影响,测算城市扩张引起的生态服务价值变化应考虑其干扰效应。以南昌市为研究区,首先测算生态服务价值变化,在此基础上,考虑不同建设用地类型的不同干扰效应,测算引入城市扩张干扰效应改进的生态服务价值,深入对比分析南昌市1995～2005年和2005～2015年间改进前后生态服务价值变化的差异。研究结果表明:(1)南昌市各城市扩张斑块的干扰强度总体较高。2005～2015年间的城市扩张干扰效应明显比1995～2005年间的城市扩张干扰效应高,城市扩张的生态成本在增加;(2)城市扩张斑块干扰效应的空间分布差异明显,周围的耕地、林地和水域面积比例较大的城市扩张斑块的干扰效应较高;(3)基于改进方法评估的城市扩张引起的生态服务价值变化大于改进前方法评估的生态服务价值变化,不同的邻域组成,不同来源类型的城市扩张斑块的生态服务价值变化差异明显。研究结果有助于科学合理度量城市扩张引起的生态系统服务价值变化,并为城市扩张生态成本的测算提供科学的支撑。

Improvement of the Evaluation Method for Ecosystem Service Value with Interference Effect of Urban Expansion

Urban sprawl squeezes the natural environment space on scale, and structurally increases the degree of habitat fragmentation. In addition, it has a negative impact on the cities’ ecological neighborhood, which should be taken into consideration when measuring the change of ecological service value caused by urban sprawl. This paper took Nanchang city as the study area and measured the change of ecological service value. On this basis, we probed into the interference effect of different types of construction land, and estimated the ecological service value enhanced by introducing the differentiate interference effect. Thus we compared the change of ecological service value from 1995 to 2005 with that from 2005 to 2015, and then made an in-depth analysis of differences before and after method improvement. The results showed that, the interference intensity of urban sprawl patches in Nanchang was relatively high in general. The interference effect of urban sprawl between 2005 and 2015 was obviously higher than that between 1995 and 2005, which indicated that the ecological cost of urban sprawl was increasing. Second, the spatial distribution of interference effect had significant difference. To be specific, the urban expansion patches surrounded by more cropland, woodland and waters presented higher interference effect. Third, the change of ecological service value estimated by improved method was larger than that without improvement. For the urban sprawl patches with different composition of neighborhood or different types of source, significant difference was observed in the change of ecological service value. We believe that the method and its application in the study area can aid in measuring the change of ecological service value caused by urban sprawl, and thereby provide technological support for estimation of ecological cost in the course of urban expansion.