生境破碎化过程对流域生境质量的影响

近几十年来,随着工业化、城市化的加速推进,人类活动对自然生境的干扰越来越频繁,导致生境破碎化与生境质量下降。在流域尺度上科学模拟生境破碎化过程及其对生境质量的影响,对于提升生物多样性和生态系统功能具有重要意义。以鄱阳湖流域为研究区域,基于InVEST模型分析区域生境质量的演变特征;从生境面积、生境边缘和生境隔离三个特征维度模拟生境破碎化过程;采用广义加性模型和地理探测器探究不同生境破碎化过程对生境质量变化的影响与交互作用。研究结果表明:(1)鄱阳湖流域生境质量呈下降趋势,从2000年的0.7862下降到2010年的0.7807,再下降到2020年的0.7715,但总体生境质量较好。生境质量较优的区域主要分布在流域南部、东北部以及西部地区,生境质量较差的区域主要分布在各个子流域的交界处。(2)2000-2010年,鄱阳湖流域生境面积占比下降、生境边缘增加和生境隔离增加三个生境破碎化过程分别占总研究区网格数的34.70%、30.15%和4.50%;2010-2020年分别占总研究区网格数的34.80%、30.69%和4.40%;2000-2020年分别占总研究区网格数的40.82%、37.50%和5.46%。生境面积减少的网格主要集中在鄱阳湖流域的中北部地区;生境边缘增加的网格分布和生境面积减少的网格分布相似;相比之下,生境隔离增加的网格较少,主要分布在各城市的中心城区范围。(3)生境破碎化过程对生境质量具有显著影响,两者呈非线性负相关关系;三个生境破碎化过程两两之间交互作用对生境质量的影响呈现双因子增强趋势。研究结果可为鄱阳湖流域生态格局优化与生境质量提升提供科学参考。

Influence and interactions of habitat fragmentation processes on habitat quality in watersheds

In recent decades, with the acceleration of industrialization and urbanization, human activities have interfered with natural habitats more and more frequently, leading to habitat fragmentation and habitat quality decline. Scientific simulation of the habitat fragmentation process and its impact on habitat quality at the watershed scale is of great significance to enhance biodiversity and ecosystem functioning. Taking Poyang Lake Basin as the study area, the evolution characteristics of regional habitat quality were analyzed based on the InVEST model firstly in this study. Then, the habitat fragmentation process was simulated from three characteristic dimensions of habitat area, habitat edge, and habitat isolation. Finally, the generalized additive model and geographic detector were used to explore the influence and interaction of different habitat fragmentation processes on the change of habitat quality. The results showed that: (1) the habitat quality of Poyang Lake showed a decreasing trend, from 0.7862 in 2000 to 0.7807 in 2010, and then to 0.7715 in 2020, but the overall habitat quality was better. The areas with better habitat quality were mainly distributed in the southern, northeastern and western parts of the basin. On the contrary, the areas with poorer habitat quality were mainly distributed at the junction of various sub-basins. (2) From 2000 to 2010, the three fragmentation processes of the decreased habitat area, the increase of habitat edge and the increased habitat isolation in Poyang Lake basin accounted for 34.70%, 30.15% and 4.50% of the total grid number of the study area, respectively; and accounted for 34.80%, 30.69% and 4.40% of the grid number of the total study area, respectively, from 2010 to 2020; and 40.82%, 37.50% and 5.46% of the total study area grids from 2000 to 2020, respectively. The grids with reduced habitat area were mainly concentrated in the central and northern areas of Poyang Lake basin. In contrast, the grids with increased habitat isolation were less, mainly in the central urban area of each city. (3) The habitat fragmentation process had a significant impact on habitat quality with a non-linear negative correlation. The interaction between the the three habitat fragmentation processes showed a two-way enhancement trend on habitat quality. The results can provide scientific references for the optimization of ecological pattern and the improvement of habitat quality in Poyang Lake basin.