Seasonal Patterns in Recoverable Underground Reserves in Spartina Alterniflora Loisel.

Seasonal differences in recoverable underground reserves in stands of Spartina alterniflora Loisel. were measured in Georgia and Delaware. They indicate that by winter substantial reserves are stored in both northern and southern marshes. Cycles of the quantity of stored reserves have greater amplitudes than cycles of the concentration of storage compounds reported in the literature. Maximum concentrations apparently occur at the same time as maximum storage tissue volumes. Seasonal measurements and defoliation studies in Delaware indicate that reserves are nearly exhausted by spring growth and that at least ⅓ are not replenished until after seed filling in the fall. This pattern of nearly complete utilization of reserves in spring with late fall replenishment may have an advantage for herbaceous perennial plants which are part of detritus based food webs. A cycle where substantial reserves are retained for canopy regeneration after early summer defoliation would be advantageous where a grazing web was dominant.