Coupling Effects of Terracing and Vegetation on Soil Ecosystem Multifunctionality in the Loess Plateau, China

Abstract

In semi-arid and arid terrestrial ecosystems, terracing and vegetation may improve soil conditions and enhance habitats. Considerable recent works have focused on evaluating how terracing and vegetation affect individual ecosystem function, but none of these evaluations included soil ecosystem multifunctionality (SEMF), which has a positive significance for optimizing soil ecosystem management. Based on the survey data of six different combinations of terracing and vegetation in the Chinese Loess Plateau, 15 functional indicators related to soil fertility, nutrient transformation/cycling, and water conservation were selected. The maximum conversion of the mean value method was employed to quantify SEMF. Concerning individual ecosystem services, the capacities of half-moon terraces-Pinus tabulaeformis (Ht-P. tabulaeformis) and level benches-Caragana korshinskii (Lb-C. korshinskii) to maintain soil fertility were 43.25% and 42.01% higher than those of counter-slope terraces-Platycladus orientalis (Ct-P. orientalis). On the contrary, Ct-P. orientalis showed better nutrient transformation and cycling services, which was 9.23% higher than those of Ht-P. tabulaeformis, therefore, we observed the highest SEMF in the Ht-P. tabulaeformis. Terracing, with a 29.2% explained variation, had a greater influence than that of vegetation (12.6%), while the coupling effect of terracing and vegetation (37.9%) was the most important factor that determined the SEMF. Thus, Ht-P. tabulaeformis and Lb-C. korshinskii should be promoted in the Loess Plateau area. The results of this study have significance in terms of understanding the interactions between terracing, vegetation, and soil ecosystems.