Comparison ofSpartina alterniflora loisel. Transplants from different locations in a man-initiated marsh in North Carolina

Abstract

Short and tall height form transplants ofSpartina alterniflora from Beaufort were compared with intermediate height form plants from three other North Carolina locations (Oregon Inlet, Ocracoke Island, and Snow’s Cut) at a common site for five growing seasons to determine variation in growth response as related to marsh initiation. In September, 5 months after planting, there were significant differences in height, basal area, and aboveground dry weight among transplants from the five locations. By the end of the second growing season, 17 months after planting, Beaufort short plants were still significantly shorter than those from any other location except Oregon Inlet and Beaufort tall plants were still taller than Beaufort short or Oregon Inlet plants. For the first two growing seasons, flowering occurred sequentially from north to south based on the site of origin of the transplants. Of five measures of growth, only the number of flowering culms m⁻² differed significantly by the end of the third growing season, 29 months after planting. Over the 5 years, Beaufort tall plants at higher elevation and exposed to shorter periods of inundation decreased in height while the height of Beaufort short plants remained essentially unchanged. The reverse was observed in the lower elevation zone, inundated longer, where Beaufort short plants increased in height and the height of Beaufort tall plants remained essentially unchanged. Results support the ecophene, rather than ecotype, status of short and tall height forms. Results further indicate that transplants from different locations, over a relatively narrow latitudinal range, can vary in several measures of growth response for several growing seasons and suggest that it would be best to use transplants from stands of intermediate height form from recently colonized sites for stabilization and initiation of marsh development projects.