Landscape pattern evolution and ecological security evaluation of Hainan Island, southern China under background of land use transformation

Objective This paper studies the spatio-temporal evolution of landscape ecological security pattern in Hainan Island of southern China to provide a theoretical basis for optimizing the local land use structure and enhancing ecosystem management.

Method We explored the spatial-temporal evolution characteristics and driving mechanisms of Hainan Island’s landscape ecological safety patterns based on land use, afforestation and socio-economic data during 2000−2020 by means of land use transition matrix analysis and landscape ecological security index calculation.

Result (1) Forest land and cultivated land were dominant landscape types in the past two decades, with an average area proportion of 67.01% and 24.76% of the study area, respectively. In general, the land use changes had exhibited overall stability with drastic variations, increase in built-up land (1 241.82 km²) and decrease in grassland (1 049.38 km²) were most notably, with changing rates of 232.45% and 67.31%, respectively. (2) The landscape fragmentation in Hainan Island had intensified, especially for cultivated and built-up land. However, landscape contagion and connectivity had improved, while landscape diversity and uniformity had shown a phase of “first decrease, then increase.” (3) The overall landscape ecological safety level of Hainan Island had deteriorated. During the 20 years, the proportion of area with low and lower security level area increased by 10 824.10 km², and high and higher security level area decreased by 13 122.56 km². By 2020, the high and higher security level area only accounted for 47.52%. Spatially, the landscape ecological safety level in the central and southern parts of Hainan Island had gradually improved and stabilized, while the coastal areas had progressively deteriorated. (4) In addition, the landscape ecological security was featured by significantly spatial agglomeration. The aggregation unit gradually changed from “dispersed” to “centralized”, with high-high value clustered in the south central and low-low value clustered in the coastal area in 2020.

Conclusion The rapid expansion of urbanization land demand and the decrease of afforestation are main reasons for degradation of landscape ecological security in Hainan Island. In the future, ecological conservation efforts in the central and southern regions of Hainan Island should be continuously promoted to ensure the effectiveness of its ecological barrier function; at the same time, ecological restoration in coastal areas should be strengthened to optimize its landscape ecological safety pattern and ensure the long-term stability of ecological safety levels.