1965年以来6个时期广东潼湖湿地的景观格局和生境质量

Landscape Patterns and Habitat Quality of Tonghu Wetlands in Guangdong Province for 6 periods since 1965

利用1965年、1977年、1986年、1993年、2006年和2017年的地形图或遥感影像数据,应用空间分析方法和In VEST模型,研究广东省潼湖湿地景观格局特征与生物多样性变化。结果表明,1965年以来,潼湖湿地景观格局发生显著变化,与1965年潼湖复杂的自然形状相比,1977年,潼湖被改造成长约7 km、宽约1 km的长方形湖泊;天然湿地持续萎缩,到2017年,天然湿地面积约减少了50%,人工湿地面积波动减少,非湿地不断扩张;1977-1993年期间,为追求更高的经济收益,约30%的水田被改造成鱼塘;受劳动力、水资源的制约和追求更高的经济收益,1993-2017年期间有接近40%的水田被改造成旱地;1977-2017年期间5个时期研究区的生境质量指数从0.63降至0.32,作为威胁源的建设用地不断增加和生境适宜性高的湿地面积持续减少,导致研究区生境质量逐年下降,生物多样性水平降低,潼湖湿地的东北部和西南部生境退化严重;因工业化与城镇化发展迅速,使得大量湿地被建设用地所侵占。

The landscape patterns of Tonghu wetlands in Guangdong province in 1965, 1977, 1986, 1993,2006, and 2017 and their changes were analyzed using data of topographic map and remote sensing images;and the spatial analysis method and the In VEST model were applied. The results showed that the landscapes of Tonghu wetlands changed dramaticly since 1965, comparing to the complex natural shape of Tonghu wetlands in 1965, a 7 km × 1 km rectangular lake was formed in Tonghu wetlands in 1977; natural Tonghu wetlands continued to shrink, by 2017, the area of natural Tonghu wetlands has reduced about 50%, and the areas of constructed wetlands was fluctuation decrease and of non-wetland expanded continuously; from 1977 to1993, about 30% of paddy fields transformed into fish ponds for higher economic benefits; and nearly 40% of paddy fields transformed into dry land from 1993 to 2017 constrained by labor and water resources and pursuing higher economic benefits; from 1977 to 2017, the habitat quality indexes dropped from 0.63 to 0.32, the area increase of construction lands, regarded as the threat source, and the decrease of the wetlands area with high habitat suitability resulted in a decline of habitat quality index as well as biodiversity; the severely degraded habitats were mainly in the northeast and southwest of the study area; the rapid development of industrialization and urbanization led to the expansion of construction lands and a lot of wetlands were occupied.