Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Effects of spatial expansion between Phragmites australis and Cyperus malaccensis on temporal variations and bioaccumulation of vanadium in coastal marshes of the Min River estuary, Southeast China.

Abstract

Vanadium (V) plays an important role in physio-ecological processes of marsh plants. The effects of spatial expansion between invasive species (Phragmites australis, PA) and native species (Cyperus malaccensis, CM) on temporal variations and bioaccumulation of V in coastal marshes of the Min River estuary were investigated by space-for-time substitution method. In situ filed sampling was conducted in PA marsh (PAM, before expansion), CM marsh (CMM, before expansion) and ecotonal marsh (EM, during expansion, marsh plants were denoted by PA' and CM') in different seasons. Results showed that, over all sampling seasons, the mean V contents in marsh soils ranged from 99.71 to 108.41 mg.kg-1 which exceeded its background value in soils of Fujian province (78.3 mg.kg-1). The V levels in soils differed among seasons or marshes and higher values in PAM, EM and CMM soils were generally observed in spring and winter. The temporal variation of V levels in EM soil rested with the alterations of pH, SOM and plant ecological traits during spatial expansion. The V contents in PA, PA', CM' and CM differed among tissues and higher bioaccumulation occurred in roots. The V levels in tissues differed among species or seasons, which could be ascribed to the differences in ecological traits among plants and the competitive absorption for V by plants during spatial expansion. This paper confirmed that the V in marsh soils of the Min River estuary existed enrichment process and the spatial expansion between PA and CM promoted its enrichment in soils and its bioaccumulation by plants. The findings of this study were favorable for understanding the biogeochemical behaviors of V in marsh ecosystem and strengthening the marsh conservation by regulating its bioavailability in soils.