白洋淀生境空间格局演变分析

Analysis of the spatial pattern evolution of Baiyangdian habitat

【目的】科学合理的生境空间格局是浅水湖泊发挥生态功能的基础。【方法】在景观生态研究尺度上引入水位从而实现年内尺度基于生境格局的动态变化研究,结合地形、历史土地利用数据和相关规划对白洋淀动植物适宜生境进行八种生境空间分类,分析1980-2017年、2030年规划情景等不同时期白洋淀生境空间格局变化和演变趋势。【结果】结果表明:(1)白洋淀生境空间之间的转化受水位驱动,其中在2000-2010年期间,类型四向类型一和类型二的转换强度最大,而在2030年规划情景下,类型二退出,将全部向以类型七为主的其他生境空间转换。(2)1980-2017年,整体生境空间破碎化程度逐渐加剧,生境空间的优势度减弱,空间异质性增强。在2030年规划情景下,整体生境空间的异质性进一步增强,聚集度下降,而各生境空间内部的空间连通性增强,类型七生境空间将成为主要优势类型。(3)未来情景下,整体水陆比将接近13∶2,生境空间格局合理性相对提高。【结论】水位是白洋淀生境空间转化的重要影响因素之一,未来生境空间异质性呈上升趋势,有利于白洋淀生态系统在更精细时间尺度上维持健康状态。研究成果能够为开展白洋淀生态修复保护与环境精准治理提供科学依据。

[Objective]A scientific and reasonable spatial pattern of habitats is the basis for the ecological functions of shallow lakes.[Methods]This paper introduces water levels at the scale of landscape ecology research so as to achieve dynamic changes in habitat patterns based on intra-annual scales.The spatial classification of habitats suitable for plants and animals in Baiyangdian was carried out by combining topography,historical land use data and relevant plans,and the changes and evolutionary trends of habitat patterns in Baiyangdian in different periods such as 1980—2017 and 2030 planning scenarios were analysed.[Results]The results show that:(1)The transformation between habitat spaces in Baiyangdian is driven by water levels,with the greatest intensity of transformation from type IV to type I and type II during 2000—2010,while under the 2030 planning scenario,type II exits and will all be transformed to other habitat spaces dominated by type VII.(2)From 1980 to 2017,the overall fragmentation of habitat space gradually increases,the dominance of habitat space decreases and spatial heterogeneity increases.In the 2030 planning scenario,the heterogeneity of the overall habitat space further increases and the degree of aggregation decreases,while the spatial connectivity within each habitat space increases and Type VII habitat space will become the main dominant type.(3)Under the future scenario,the overall water-land ratio will be close to 13∶2,and the spatial pattern of habitats will be relatively more reasonable.[Conclusion]Water level is one of the important influencing factors for the spatial transformation of habitats in Baiyangdian,and the spatial heterogeneity of habitats is on the rise in the future,which is conducive to maintaining the health of Baiyangdian ecosystem at finer time scales.The result of the study provide a scientific basis for carrying out ecological restoration and protection and precise environmental management of Baiyangdian.