Determination of ecological restoration patterns based on water security and food security in arid regions

Food and water security are crucial for sustainable development in arid regions. However, land use/cover change often leads to trade-offs between grain yield and water-related ecosystem services (ESs), threatening food and water security. Therefore, how to optimize ecological restoration patterns to ensure grain yield and ESs is an important issue in arid regions. This study evaluated the changes in grain yield, water yield (WY), and water purification (WP) from 2000 to 2020 in the Bosten Lake region, China. Then, planting vegetation (PV) scenarios on different slopes and riparian vegetation buffer (RVB) scenarios with different widths were established to reveal the effects of different ecological restoration rules on ESs. Finally, the optimal ecological restoration scenario was determined based on ES efficiency and trade-offs/synergies. The results showed that grain yield increased (23.83%) at the expense of WP and WY (- 14.76 % and - 0.57%) from 2000 to 2020. The agricultural development scenario further reduced WP (- 7.99 %). Grain yield increased and WP and WY decreased under the PV scenarios. The RVB scenarios had the potential to improve ESs, guarantee grain yield and eliminate ES trade-offs. The effect of forest restoration on ESs was greater than that of grassland restoration, and the effect of RVB scenarios on ES efficiency was greater than that of PV scenarios. With the increase in the riparian buffer zone, the WY efficiency increased nonlinearly, and the WP efficiency decreased nonlinearly. The riparian grass buffer scenarios achieved higher WP at the expense of less WY, with the 200 m wide riparian grass buffer being the best ecological restoration scenario. The ecological benefits varied with the type, location, and scale of vegetation restoration. This study proposed a framework to determine the optimal ecological restoration pattern. The results can provide a scientific reference for water resource management decision-making in arid regions.