Attempts to revegetate coastal areas with valuable mangrove cover have utilised several approaches including air-layering, the results of which are reported here. The 3 Florida mangrove species Rhizophora mangle, Avicennia germinans and Laguncularia racemosa were subjected to girdling (stripping the bark and phloem to the cambium), after which layers or shoots were attached internodally and wrapped with sphagnum moss and aluminium foil. Layers were checked for root growth and for leaf and branch senescence at 15-25 day intervals. Rooting success was highest in R. mangle (39%), followed by L. Racemosa (35%) and A. germinans (6%). Similar variations between the species were noted with respect to the form, length and number of roots, and callus formation. The results warrant continued investigation into air-layering as an alternative to planting propagules or transplanting older specimens. The economics, drawbacks and uncertainties associated with air-layering at present are discussed. |
