At each of the four sites, shrub production will be estimated with a growth index. The index is calculated by determining dry mass production of new shoots on the shrubs. Fifty shoots will be harvested from shrubs at each site at the end of the growing season (early October). The shoots will be oven dried and weighed to determine production. In addition, at least one 5 x 5 m plot will be established in the vicinity of the foredune. Shrub colonization will be followed within the plot during the spring, summer and fall of each year. New shrubs, dead shrubs and species composition will also be recorded. Additional measurements of shrub growth will include changes in plant water status for plants at the four sites as water availability changes throughout the growth season. Plant water status will be determined by diurnal measurements of stomatal conductance with a porometer and of leaf water potential with a pressure chamber. If and when time permits, to facilitate comparisons among several woody species common to barrier islands, additional measurements will record interspecific differences in the effects of experimental changes in the depth of the water table as controlled by solar powered pumps on the small pimples located on the island.