Soil seed bank dynamics are regulated by bird diversity and soil moisture during alpine wetland degradation

Abstract

Increased anthropogenic activities and global warming have accelerated the loss of wetlands worldwide. Given that a seed bank plays an important role in maintaining species diversity, understanding the regulatory mechanism of seed bank dynamics is crucial for using seed banks for restoration of species diversity in degraded wetlands. We collected data on biotic (i.e., aboveground vegetation, birds and rodents) and abiotic (i.e., soil environmental factors) ecosystem components as predictors along a degradation gradient in an alpine wetland and then to identify the relative importance of multiple sets of predictors in the regulating seed bank dynamics (i.e., species richness and composition). Seed bank dynamics were less responsive to environmental change than the aboveground vegetation during wetland degradation. Soil moisture and bird richness were more important than other predictors in regulating species richness and species composition of the seed bank, respectively. Our results suggest that seed banks can be used as potential resources for restoration of degraded wetlands. Birds play an important role in regulating the diversity of wetland ecosystems (seed bank is a potential diversity provider). Therefore, more attention should be paid to the protection of bird diversity in the process of conservation and restoration of degraded wetlands.