Effects of phenological stage ofSpartina alterniflora transplant culms on stand development

Abstract

Spartina alterniflora culms dug from a naturally established seedling stand, and from tall- and dwarf-form stands were transplanted on a coarse (Area I) and a fine textured (Area II) substrate of similar elevation. Soil amendment treatments of 122.0 and 244.0 kg ha⁻² each of inorganic N, P₂O and K₂O and a commercial root dip treatment were applied to the three culm types. The seedling culm type was the superior transplant material in terms of initial survival, rapid tiller production and below-ground biomass accumulation. The dwarf- and tall-form culms were from more mature stands and did not have a comparable flush of growth. Although initial transplant survival was slightly less in Area II, vegetative growth of all three culm types was more rapid than on the coarse textured substrate. Increased water holding capacity and nutrient availability of the fine textured substrate probably reduced osmotic stress between tidal inundation in the summer months and promoted growth throughout the year. At 16-mo postplanting, only the seedling culms were similar to natural stands in the vicinity in terms of culm density. Root: shoot ratios of less than unity for all culm types indicated the stand was still developing.