Responses of Above-ground Biomass, Plant Diversity, and Dominant Species to Habitat Change in a Freshwater Wetland of Northeast China

— Habitat change is one of the most important driving forces of biodiversity loss and vegetation distribution in freshwater wetland. Research on the responses of plant diversity and community structure to habitat change is essential to biodiversity conservation. In this study, we demonstrated responses of the above-ground biomass, plant diversity, and dominant species to the habitat change in the Sanjiang Plain, Northeast China. Different plant diversity indicators, including the species richness, Shannon-Wiener index, and Simpson index were selected to study their sensitivities to the habitat change. The dominant species, Deyeuxia angustifolia (Kom.) Y.L. Chang, Carex lasiocarpa Ehrh, Carex pseudocuraica Fr. Schmidt and Glyceria spiculosa (Schmidt.) Roshev, were selected to illustrate their vulnerabilities to the habitat change at the population level. Besides, the relationships between water level and traits of dominant species were investigated. When the habitat changed from marsh to meadow, the above-ground biomass increased and a corresponding plant diversity loss occurred. In addition, C. lasiocarpa , C. pseudo-curaica , and G. spiculosa had higher importance values in the marsh than that in the meadow, which were contrary to that of D. angustifolia . Overall, plant diversity and community structure had significant vulnerabilities to habitat change, and habitat protection is of great importance in biodiversity conservation.