Uncovering the importance of soil type, landscape connectivity, and pedodiversity for nature’s contributions to people in a typical agricultural region

Soil type, landscape connectivity, and pedodiversity contribute directly and indirectly to nature’s contributions to people (NCP) by affecting soil properties and ecological processes such as soil and water movement. However, the effects of soil type, landscape connectivity, and pedodiversity on changes in NCP under long-term agricultural activities are largely unknown. Using the Songnen Plain of China as a representative agricultural region, this study examined changes in three NCP (soil organic carbon, soil retention, and water yield). These changes were assessed across different soil types over the period 1980–2020 using variance analysis. Landscape ecological metrics were applied to evaluate landscape connectivity and pedodiversity. The spatial relationships between these landscape properties and changes in NCP were further quantified using geographically weighted regression. In addition, a random forest model was used to evaluate the relative importance of soil properties and other environmental factors in driving changes in these indicators. The results showed that Haplic Phaeozems exhibited significantly higher levels of NCP compared to other soil types. Specifically, soil organic carbon ranged from 19.50 to 19.74 g/kg, soil retention from 22.83 to 27.03 t/ha, and water yield from 119.81 to 146.83 mm. In contrast, western regions characterized by fragile soils—such as Gleyic Chernozems, Calcic Gleysols, and Haplic Chernozems—experienced declines in one or more NCP indicators. Landscape connectivity and pedodiversity were identified as critical determinants of NCP levels, in some cases exceeding the influence of climate and vegetation. Moreover, pedodiversity showed region-specific effects, enhancing water yield in southern areas while suppressing carbon storage in the southwest. While climate and vegetation are the dominant factors shaping zonal soils such as Phaeozems and Chernozems, this study found that landscape connectivity and pedodiversity also served as critical determinants of NCP levels under long-term agricultural activities. Tillage under straw return and terrace construction on sloping land can effectively improve the three NCP. This study provides new insights into the role of soils in providing NCP.