Trade-offs among ecological functions during alfalfa grassland restoration in a semi-arid region of the Loess Plateau

To establish a scientific basis for vegetation restoration and reconstruction of alfalfa grasslands on the Loess Plateau, it is necessary to study the effects of different ecosystem functions on habitat reclamation. Accordingly, the aim of the present study analyzed different succession stages of alfalfa land in a semi-arid loess watershed, and the root mean square deviation (RMSD) method was used to analyze species diversity, aboveground carbon storage, soil moisture storage, and trade-offs between the five ecosystem functions of soil organic carbon storage and soil total nitrogen storage. The relativereturns of species diversity, aboveground carbon storage, soil water storage, soil organic carbon storage, and soil total nitrogen storage changed significantly with the community succession (P< 0.05), and the relative yields of aboveground carbon storage, soil organic carbon, and soil total nitrogen increased with succession, whereas species diversity and soil moisture consumption were reduced. All ecosystem functions were centered between soil organic carbon storage and soil total nitrogen storage, and the trade-off between these factors was minimal, which indicated that the factors were synergisticand that the whole recovery stage value was 0.13. Upon restoration to theLeymus secalinus community stage, the trade balance between the five ecological functions was the most balanced, with an average RMSD of only 0.21, and species diversity was highest at the long-shoulder grass community stage. The present study establishes a scientific evaluation system and theoretical guidance for the sustainable restoration of farmland to native habitat.