Integrating vegetation suitability in sustainable revegetation for the Loess Plateau, China

Revegetation is accelerating globally due to its benefits for ecosystem restoration, desertification prevention, and climate change mitigation. The Loess Plateau has suffered serious erosion in the past decades, and revegetation projects, such as those under the 'Grain for Green' program, have been conducted for soil erosion prevention. The irrational distribution of artificial plantations had negative consequences, including vegetation degradation, soil drying, and decreases in streamflow. Determining the suitable plant species is critical in guiding the design of revegetation programs and may help delimit the suitable boundaries for artificial plantations. In this study, we used an eco-hydrological model to quantify the suitability of two typical revegetation species (Robinia pseudoacacia and Stipa bungeana) using a developed vegetation suitability equation, which estimates the water use/water stress trade-off. The results showed that R. pseudoacacia was more sensitive to water stress than S. bungeana. The water use of both species varied along the precipitation gradient, and S. bungeana generally had a higher water use than R. pseudoacacia. Suitable areas for R. pseudoacacia were mainly located in the northeastern part of the plateau. By overlaying the suitable boundaries for R. pseudoacacia on the current land cover, we found that the area of forests distributed in unsuitable regions reached 7.31% of the entire Loess Plateau. Converting forests beyond the suitable boundary to grasslands would increase the water yield (0.51%-12.23%) and slightly decrease the soil retention capacity (0.01%-0.08%), resulting in a 'win-win' situation for sustainable plant-soil ecosystems and soil-water conservations. Additionally, the suitable area of R. pseudoacacia is predicted to shrink under projected future drying trends. In conclusion, vegetation suitability in the future planning and design of revegetation projects should be considered to effectively tackle the impacts of environmental degradation and climate change in the Loess Plateau. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Revegetation is crucial for ecosystem restoration, desertification prevention, and climate change mitigation globally. In the Loess Plateau, revegetation programs have been conducted to prevent erosion, with a study showing that Robinia pseudoacacia is more sensitive to water stress than Stipa bungeana. The predicted shrinking of the suitable area for R. pseudoacacia in the future highlights the importance of considering vegetation suitability in planning and designing revegetation projects to address environmental degradation and climate change impacts effectively.