FINE ROOT PRODUCTION ALONG A CHRONOSEQUENCE OF BARRIER ISLAND COMMUNITIES.


Mark J. Stevenson and Frank P. Day.


Fine root production was quantified by an ingrowth core method along a chronosequence of dune communities on Hog Island, a Virginia Coast Reserve LTER site. The dune communities are dominated by Ammophila breviligulata, Spartina patens, and Aristida tuberculosa. Production estimates for fine roots (<= 2 mm), were estimated using biomass ingrowth into root-free soil volumes for one growing season. Fine root production was greater in N-fertilized plots than unfertilized plots. The most substantial level of fine root production for unfertilized plots occurred in the upper 0-10 cm depth in R120. The unfertilized plots showed no real differences in production between communities at 10-20 cm, 20-30 cm and 30-40 cm depth. R24 and R36 produced similar root production measurements in their N-fertilized plots. There was no substantial increase in total phosphorous concentrations in any of the dune communities. There was an increase in total nitrogen concentrations in fine roots from all dune communities in N-fertilized plots.