基于“空间形态-破碎化-聚集度”的粤港澳大湾区森林景观格局时空演变

森林景观格局的时空演变研究能够帮助理解区域森林变化过程。传统的景观指数方法多以均值为计算结果且空间信息表达不足,基于形态学方法能够从空间上直观辨别景观类型,综合破碎化和聚集度的定量分析有助于进一步认识森林景观格局的演变特征。以1990、2000、2010、2020年粤港澳大湾区土地利用数据为基础,建立基于“空间形态-破碎化-聚集度”的综合研究框架,开展大湾区森林景观格局的时空演变研究。结果表明：(1)近30年大湾区森林形态以核心区为主,森林面积逐渐减少,而2010—2020年减少速率降低,各类型森林斑块均有所恢复;(2)整体破碎化程度较低,中部破碎化地区表现为先上升后下降的变化趋势;(3)聚集度结果表明,距离森林边界500 m内的森林斑块面积最大,约占研究区总面积的30%,而距离大于4.5 km的非森林斑块面积几乎翻倍增加,应重点关注该区域的森林损失。研究有助于全面理解森林景观格局的变化特征,相关结果可为粤港澳大湾区的森林生态修复工程、国土空间规划以及城市可持续发展提供科学依据。

Spatiotemporal evolution of forest landscape pattern in Guangdong-Hong Kong-Macao Greater Bay Area based on "Spatial Morphology-Fragmentation-Aggregation"

The study of spatiotemporal evolution of forest landscape pattern is beneficial for understanding the process of regional forest change. The traditional patch-based metrics suffer from intrinsic limitations, such as they provide a single average value and cannot provide any spatially explicit information. However, the morphological method can visually identify the type of each landscape element. Meanwhile, the quantitative analysis of integrated fragmentation and aggregation helps to further understand the evolution characteristics of forest landscape pattern. Based on the land use data in 1990, 2000, 2010 and 2020, we established a comprehensive research framework focusing on "Spatial Morphology-Fragmentation-Aggregation" to analyze the evolution characteristics of forest landscape patterns in the Guangdong-Hong Kong-Macao Greater Bay Area. The results showed that, (1) in the past 30 years, the forest core area has been dominated, and the forest area has gradually decreased. However, the decline rate decreased from 2010 to 2020, and all types of forest patches recovered. (2) The overall degree of fragmentation was relatively low, and the central fragmentation area showed a trend of first rising and then falling. (3) The aggregation degree results showed that the forest patches within 500 m from the forest boundary had the largest area, accounting for about 30% of the total area of the study area. The area of non-forest patches with a distance of more than 4.5 km has almost doubled, and forest loss in this area should be a concern. This study contributes to a comprehensive understanding of the changing characteristics of forest landscape patterns. These results can provide a scientific basis for forest ecological restoration projects, territorial spatial planning and sustainable urban development in the Guangdong-Hong Kong-Macao Greater Bay Area.