Abstract

Lightning gaps, as well as other types of canopy gaps, have been reported as an important disturbance mechanism in mangrove forests around the world. This study is the first to report multiple species-specific recruitment/mortality rates across life stages within different forest stages. I studied the survival, recruitment, and growth across three successional stages of mangrove forest (newly initiated lightning gaps, growing gaps and intact forest) for four dominate life phases (propagules, seedlings, saplings, and adult) of the three dominant mangroves (Avicennia germinans, Laguncularia racemosa, Rhizophora mangle) in the Florida Everglades. In new lighting-initiated canopy gaps the seedling recruitment rate was twice as high as the other forest stages and the sapling population was increasing. At the growing gap stage, R. mangle seedling mortality was 10 times greater and sapling mortality was 13 times greater than recruitment. In growing gaps, there is reduced seedling stem elongation, and reduced sapling and adult growth, but a few individuals (R. mangle saplings) were able to recruit into the adult size class. Enumerating survival, recruitment, and growth across life stages by species is of critical importance in understanding and predicting changes in forest structure, composition and development especially in mangrove communities. This work provides the critically needed field data for future modeling efforts to explore mangrove forest gap phase dynamics.