[Mechanisms Linking Urbanization Intensity and Landscape Pattern Changes with Typical Soil Ecosystem Service...

Urban greenspace is an indispensable component of urban ecosystems. Urban greenspace soil， possessing some typical functions such as nutrient cycling， carbon cycling， and heavy metal immobilization， plays a vital role in maintaining the stability of urban ecosystems. As the two key indicators of urban development， urbanization intensity and landscape pattern are supposed to markedly affect soil functions， but their effects remain unclear. Soil samples from the greenspaces in Hangzhou City were collected in the study， and the soil functions were quantified using the averaging approach. Then， the urbanization intensity and landscape pattern metrics （i.e.， landscape heterogeneity and connectivity） were respectively obtained from ArcGIS and FRAGSTATS， and the effects of changes in the urbanization intensity and landscape pattern on soil functions were explored using structural equation modeling （SEM）. The results showed that the increase in urbanization intensity significantly promoted soil nutrient cycling， carbon cycling， and heavy metal immobilization functions via a direct way. Interestingly， the changes in urbanization intensity indirectly affected greenspace soil functions via altering soil properties. For example， with the increase in urbanization intensity， the elevated soil clay and fines content enhanced soil nutrient cycling， and the decreased soil porosity improved soil heavy metal immobilization function. In terms of landscape pattern， increased landscape heterogeneity reduced soil carbon cycling but promoted heavy metal immobilization； as landscape connectivity increased， a decrease in soil electrical conductivity weakened soil nutrient cycling and carbon cycling. In conclusion， the increase in urbanization intensity contributes to the enhancement of soil ecosystem service functions of greenspaces， while these functions respond differently to the changes in landscape patterns. The results can provide a scientific basis for further understanding and maintenance of soil ecosystem service functions of urban greenspaces.