Gross Ecosystem Product (GEP) is a single currency to measure the contribution of an ecosystem to society. It is the sum of the value of products and services provided by the ecosystem to humans. Based on this, GEP characterizes the current situation of the ecological environment in a region and can measure the contribution index provided by ecosystems. Based on land use data, rainfall data, soil data, statistical yearbook, DEM and other data, this paper constructs the accounting framework of Hainan Island’s GEP, quantitatively evaluates Hainan Island’s GEP from 2010 to 2020 and analyzes the research results. The results are as follows: (1) The GEP of Hainan Island’s ecosystem rose from 596.404 billion CNY in 2010 to 1032.096 billion CNY in 2020, an increase of about 42.21% with an average annual growth rate of 6.3%. The overall GEP has shown an upward trend. Among them, the value of regulation service accounts for the largest proportion was up to 73–83%. (2) The overall distribution of GEP in Hainan Island is uneven, decreasing from the central mountainous areas to the eastern coastal areas around to the west. In particular, Danzhou City, Wenchang City and Haikou City have higher values, while Tunchang, Baoting County and Wuzhishan City have lower values, and Wuzhishan City has the lowest values. Hainan Island is rich in natural resources, which contain great value. Through the accounting of GEP, we can clearly determine the value of the ecosystem, which can help the relevant departments estimate the GEP of Hainan Island’s ecosystem. It can provide a reference for Hainan to formulate ecological protection and sustainable development policies, and for the GEP estimation of other islands.

The impact of human activities on ecosystems is receiving increasing attention because their mechanisms of action are complex; the spatial response of ecosystem service drivers still needs to be explored further. This study evaluated three ecosystem services—water yield, soil conservation, and carbon storage—in Hainan Province from 2000 to 2020; we analyzed the spatial and temporal changes of the ecosystem services, and the spatial heterogeneity of the influencing factors. The results were as follows: (1) The average water yield, soil conservation and carbon storage of Hainan Province from 2000 to 2020 were 42.36 billion,$8.01\times {10}^8 \mathrm{t}$ and 1.52 ×${10}^7$ t, respectively. Overall, the ecosystem services were relatively weak at lower elevations. (2) There were obvious hot spots and cold spots in the water yield and soil conservation, and the hot spot distribution of carbon storage was not obvious. (3) There were differences between the ecosystem services for different land use types; trade-off relationships only appeared between unused land and ecosystem services. (4) The precipitation, normalized difference vegetation index and elevation factors had great impacts on the ecosystem services. Most of the human activity factors showed a significant nonlinear enhancement effect during their interaction. Population and elevation had obvious spatial differentiation effects on the water yield and carbon storage services.