Productivity of Spartina alterniflora in Proximity to Mangroves

Abstract

Mangroves are salt-tolerant trees that coexist with marsh grasses and forbs at subtropical latitudes. Occasional freeze events keep mangroves from completely overgrowing marsh plants. There have not been severe freeze events within recent years which are changing the abundance of mangroves. Black mangroves (Avicennia germinans) could be outcompeting marsh plants for light or nutrients and that may decrease smooth cordgrass (Spartina alterniflora) productivity. The purpose of this study is to determine if mangroves are out-competing Spartina alterniflora by limiting nutrient availability. Field measurements of above and belowground data were quantified by measuring the growth, chlorophyll-a content, and nutrient content (carbon, nitrogen, and phosphorus) of S. alterniflora roots in plants growing within the A. germinans rhizosphere and in plants outside the area influenced by mangrove roots. The number of new leaves results suggest that A. germinans affects the productivity of S. alterniflora by limiting the above ground production.