Optimal spatial scale selection for maximizing regional ecological management benefits

Abstract

The trade-off/synergy relationship among landscape elements exhibit pronounced spatial scale dependence and it profoundly affects the scientific rationality and practical effectiveness of regional ecological management decisions by altering the mechanisms of interactions among ecosystem services. While existing studies have made progress in characterizing multi-scale differences, there is still a lack of research on determining the optimal scale of management to maximize ecological benefits. Therefore, this study constructed a framework for analyzing scale effect resolution and optimal scale identification by integrating wavelet analysis, spatial autocorrelation and semi-variational functions. At the same time, by combining the XGBoost-SHAP model to interpret environmental factors exhibiting trade-off/synergy spatial heterogeneity, we proposed an optimal management scale optimization strategy based on comprehensive error minimization and took the interactive relationships among production, liveling, and ecological land use function (LUF) within the Heihe River Basin as the empirical subject. The research findings are as follows: 1) Spatial scale expansion strengthens the overall synergy between LUFs (by 0.07–0.24) but weakens the trade-off intensity within some grid cells; 2) The optimal ecological management scale in the study area was determined through semi-variogram optimal fitting to be 7 km, at which distance the trade-off/synergy fitting degree among all LUFs was optimal (with the highest r² reaching 0.959); 3) Both natural and socio-economic factors influence the trade-off/synergy among land-use functions, and the trade-off areas are mainly located in the densely populated central oasis areas (accounting for up to 13.93% of the watershed). This study proposed an integrated spatial governance system comprising core conservation, transitional regulation, and collaborative development. Building upon this, we contended that mitigating land use function trade-off primarily requires differentiated management strategies, including optimizing land use structures (avoiding excessive expansion of construction land), controlling population density, and preventing excessive concentration of economic scale (GDP). This study provides methodological support for resolving the multi-scale ecological management decision and sustainable development dilemma.