Urban Expansion Was the Main Driving Force for the Decline in Ecosystem Services in Hainan Island during 1980–2015

Abstract

Hainan Island is one of China’s most ecologically diverse areas. Human activities and climate change have recently influenced Hainan Island’s ecosystem services. Therefore, scientific methods are urgently needed to investigate the characteristics of these services’ spatial and temporal variations and their driving mechanisms for maintaining Hainan Island’s biodiversity and high-quality ecological conservation. Based on multivariate remote sensing and reanalysis data, this study analysed the spatial and temporal variations in water retention, soil conservation, carbon sequestration, and oxygen release services on Hainan Island during 1980–2015 using various ecosystem service models such as INVEST, CASA and RULSE. Then, we analysed different ecosystem service drivers using a random forest model. The results indicated that (1) from 1980 to 2015, the change characteristics of different ecosystem types (arable, forest, and grassland) decreased, and the proportion of decrease was 0.98%, 0.55% and 0.36%, respectively. Built-up and water increased significantly, and the proportion of increase reached 1.46% and 0.51%, respectively. (2) Hainan Island’s functions of water retention, soil conservation, carbon sequestration, and oxygen release services decreased from 23.31 billion m3, 2.89 billion t, 9.68 million t and 56.05 million t in 1980 to 23.15 billion m3, 2.79 billion t, 9.42 million t and 55.53 million t in 2015, respectively. The high value area was mainly distributed in Hainan Island’s central mountainous area, and the low value area was mainly distributed in the lower-elevation coastal area. (3) In the past 35 years, urban expansion has been the leading factor in the reduction of Hainan Island’s ecosystem service capacity. However, its central nature reserve and other forms of ecological protection have improved its ecosystem service capacity, which has alleviated the overall declining trend of its amount of ecosystem service functions. (4) The driving forces for the spatial distribution of Hainan Island’s ecosystem services were analysed using a random forest algorithm, which indicated that its spatial distribution was mainly driven by rainfall, soil moisture, actual evapotranspiration, maximum temperature, and minimum temperature. This study is expected to help planners develop effective environmental policies to accommodate the potential ecological risks associated with urban expansion during the construction of Hainan Island’s future free trade port while filling the gaps in existing studies.

Importance of ecosystem services and ecological security patterns on Hainan Island, China

“…Under the influence of human activities, global climate change and other factors, Hainan Island is facing ecological risks such as biodiversity decline, wildlife habitat reduction, water conservation capacity reduction, and serious soil erosion in local areas, which threaten ecosystem stability, ecological security, and human wellbeing (Geng et al, 2022). This study adequately describes the spatial variation of the importance of ecosystem services and ecological security elements.…”

The Evaluation Method of the Marine Spatial Suitability for Islands from the Perspective of Sustainable Development: A Case Study of the Pingtan Islands

“…The sustainable development and land-sea coordination fields have been extensively researched by experts and scholars in recent years, including connotations [17,18], strategies [19,20] and frameworks [21][22][23], as well as relevant evaluation indexes of land-sea coordination or sustainable development [24], which have been applied to coastal cities [25,26], ports [27] and spatial planning [28]. As a special spatial element of land and sea, research on the land-sea integration of islands, particularly inhabited islands, has focused on the opportunities and challenges associated with the land-sea integration [29][30][31], network governance [32][33][34] and ecological protection of islands [35,36]. A conceptual theory and framework study of sustainable development has gradually been extended to the measurement of island classification management and the evaluation of marine space suitability.…”