Growth of southern cattail (Typha domingensis pers.) seedlings in responseto fire-related soil transformations in the Northern Florida Everglades

The interaction between plant growth and nutrient availability is an import ant aspect of vegetation dynamics in wetlands. In this study, seedlings of Typha domingensis were used to assay the nutrient availability of fire-dist urbed Florida Everglades soils. Seedlings were planted in soils that had be en naturally muck- (MB), surface- (SB), or non-burned (NB) and that showed significant differences in concentrations of inorganic:total phosphorus acc ording to fire severity. After two months of growth, plant height, number o f leaves, culm diameter, number of rhizomes, length of rhizomes, live leaf biomass, and above- and belowground biomass were greatest in MB seedlings. In addition, root architecture and biomass allocation were influenced by so il type. Seedlings from NB and SB soils developed thinner roots with numero us root hairs and had higher percentages of below-ground biomass. In contra st, seedlings grown in muck-burned soils developed large rhizomes in additi on to thicker, hairless roots while allocating proportionally more biomass to aboveground parts. Tissue nutrient analyses showed that both experimenta l and field-harvested plants grown in MB soils contained significantly more phosphorus than plants from SB or NB soils. Typha domingensis has displace d plant communities in areas of the Everglades that receive nutrient-enrich ed agricultural runoff. However, this study suggests that establishment and expansion of this species also may occur in overdrained regions of the Eve rglades where muck fires are a frequent occurrence. In addition to creating an opening in the landscape, muck fires increase the bioavailability of so il phosphorus, thus providing a competitive advantage for T. domingensis.