Chronosequential changes in soil-related ecosystem services after coastal reclamation: Insights for coastal cropland protection

Abstract

Coastal reclamation has been used widely to accommodate urbanization and support increasing food demand. However, the responses of soil properties and soil-related ecosystem services (SES) to reclamation remain unclear. There are no effective operational methods for calculating the SES provided by reclaimed cropland. Using field sampling data of soil properties, we proposed a framework to evaluate the influence of reclamation on the soil's ability to provide five SESs: plant growth support (SES1), carbon storage (SES2), nutrient cycling (SES3), erosion control (SES4), and habitat provision (SES5). A series of SES indices were constructed accordingly and tested using data from a reclaimed soil chronosequence over 700 years in Hangzhou Bay, China. The results showed that all the SES indices increased significantly along the reclamation chronosequence, with the highest impact for SES2 (273.7% of soil C storage growth) owing to long-term continuous cultivation and fertilization. Most of the indices have a different logarithmic relationship with reclamation time, with a faster growth rate in the first 50 years, while SES1 increases linearly with reclamation time. Using soil organic matter as a reference, the sensitivity of SESs to reclamation is SES4 > SES2 > SES5 > SES3 > SES1. The significant positive correlations between all SES indices suggest that the provision of the five SESs is interdependent, with strong synergy. Our methods and index system can be effectively used to monitor coastal cropland protection and promote sustainable management of reclaimed land.