Community-Level Allometric Relationships Among Length, Planar Area, and Biomass of Fine Roots on a Coastal Barrier Island

Abstract

predict biomass and biomass change. The objective of this study was to determine if predictive communitylevel allometric relationships between root length, planar area and biomass existed in a coastal barrier island dune ecosystem. Fine root samples were extracted monthly from four dune and swale areas along a chronosequence (6, 24, 36, and 120 years old) on Hog Island, part of the Virginia Coast Reserve-Long Term Ecological Research site. Dominant life forms were rhizomatous perennial grasses on the dunes and in younger swales and shrubs in the older swales. Root planar area in May and August yielded the stronger regression relationships, with winter values exhibiting greater variability. An analysis of covariance (ANCOVA) was used to examine the heterogeneity of regression slopes among sample dates. Both root length and area models exhibited significantly greater slopes during the course of the growing season. The regression slopes for the oldest dune site displayed no significant differences with season for either length or area. Data from the swales produced stronger predictive relationships than the dunes. These results provide a foundation for indirect root biomass estimates in this system.