长江中下游生境质量演变及其对土地利用变化的响应分析

Habitat Quality Evolution and Its Response to Land Use Change in the Middle and Lower Reaches of the Yangtze River

摘要:

长江中下游作为我国南方重要的生态屏障，明晰土地利用格局变化对生境质量的影响对流域生态保护、资源可持续发展具有重要意义。以2000年、2010年、2020年3期土地利用数据为基础，采用土地利用转移矩阵、动态度模型，分析土地利用时空变化特征，并借助InVEST模型探究其生境退化度和生境质量时空演变规律，进一步探讨生境质量动态变化对土地利用变化的响应。结果表明：耕地、林地为长江中下游主要土地利用类型，并与草地呈现农林草交错特点，建设用地多沿河流呈多点扩散化分布于研究区东北部，扩张趋势最为明显，主要来源于耕地。长江中下游生境质量整体处于良好水平，但呈不断退化态势，总体呈“东北低西南高”的空间分异格局，生境退化度指数持续增大，但增幅下跌，整体呈现除长江三角洲外中间强外围弱的效果。耕地向林地转移对生境改善影响最大，而林地转换为耕地则对研究区生境质量负面影响最大。研究结果可为土地格局优化、生境质量提升以及流域生态一体化保护与系统治理提供科学参考。

Abstract:

As an important ecological barrier in southern China, the middle and lower reaches of the Yangtze River are of great significance for ecological protection and sustainable development of resources in the basin by clarifying the impact of land use pattern change on habitat quality. Based on land use data of 2000, 2010 and 2020, the spatiotemporal change characteristics of land use have been analyzed by using land use transition matrix and dynamic degree model, and the temporal and spatial evolution of habitat degradation and habitat quality has been explored with the help of InVEST model, so as to further explore the response of dynamic change of habitat quality to land use change. The results showed that cultivated land and forest land are main land cover types in the middle and lower reaches of the Yangtze River, and shows the characteristics of agriculture, forestry and grassland interlacing with grassland. The construction land is mostly distributed in the northeast of the study area along the river, and the expansion trend is the most obvious. It is mainly from cultivated land. The habitat quality in the middle and lower reaches of the Yangtze River is at a good level as a whole, but it shows a continuous degradation trend, and the overall spatial differentiation pattern is "low in the northeast and high in the southwest". The habitat degradation index is continued to increase, but the growth rate is decreased. It shows the effect of being strong in the middle and weak in the outside except for the Yangtze River Delta. The transfer of cultivated land to forest land has the greatest impact on habitat improvement, while the conversion of forest land to cultivated land has the greatest negative impact on habitat quality in the study area. The results of this study can provide a scientific reference for the optimization of land pattern, the improvement of habitat quality, and the integrated protection and system management of watershed ecology.