Assessing and Predicting Ecosystem Services and Their Trade-Offs/Synergies Based on Land Use Change in Beijing-Tianjin-Hebei Region

Exploring the spatial and temporal dynamic changes in ecosystem service functions and trade-off/synergistic relationships over a long time series in the Beijing-Tianjin-Hebei region is of great practical significance for regional high-quality development. Taking the Beijing-Tianjin-Hebei region as the research object, PLUS was used to predict the land use distribution in 2030 under three scenarios: business as usual (BAU), cropland protection scenario (CPS), and ecological protection scenario (EPS); the InVEST model was introduced to assess ecosystem services including water yield (WY), carbon stock (CS), habitat quality (HQ), and soil conservation (SC); trade-offs/synergies among ecosystem services were calculated by using R and GeoDa modeling. The results show the following: (1) Between 1980 and 2020, the study area witnessed varying trends in WY and SC, which initially decreased and subsequently increased, showing an overall upward trend. In contrast, CS and HQ consistently declined throughout the period; the HQ, CS, and SC values were high in the northwest and low in the southeast, while the WY value was high in the southeast and low in the northwest. (2) From 1980 to 2020, the relationships SC-HQ and CS-HQ, as well as CS-SC, were characterized by synergy. In contrast, the interactions CS-WY, SC-WY, and WY-HQ demonstrated trade-offs. On the whole, the trade-off/synergy degree showed a trend of fluctuating increase. From the perspective of the spatial scale, CS-HQ, CS-SC, SC-HQ, and WY-HQ were mainly cooperative relationships. CS-WY and SC-WY were trade-off relationships. (3) Compared with 2020, the total ecosystem service of the four types decreased, increased, and increased under business as usual (BAU), the ecological protection scenario (EPS), and the cropland protection scenario (CPS), respectively, and the increase was the highest under the ecological protection scenario. In terms of time scale, there were also differences in the trade-off intensity among ecosystem services under the three scenarios. In the EPS, the trade-off/synergy intensity among various ecosystem services was the highest, followed by the CPS, and the lowest was under BAU. The findings of this research offer theoretical insights and practical guidance for enhancing ecosystem services and zoning functions in Beijing-Tianjin-Hebei, while also providing fundamental support for refining the territorial spatial configuration.