{'fraction_non_alphanumeric': 0.021642266072565246, 'fraction_numerical': 0.008911521323997454, 'mean_word_length': 4.887640449438202, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Structure de la Végétation et Production Primaire dans la Mangrove de la Baie de Fort‐de‐France, Martinique (F.W.I.)

A comparative study of vegetation structure and primary production was conducted at two mangrove sites differing essentially from each other due to their hydrological conditions. At each site, stand structure was characterized along a transect set up in the main slope direction. Litter fall was monitored using 0.5 m2 traps, and girth increment by means of fixed dendrometer bands. Stands at site A, under prevailing marine influence, were characterized by the abundance of Avicennia germinans dead trunks and multistemmed trees, by the predominance of the shrub form of Rhizophora mangle, and by a much lower dominant height and basal area than in stands at site B which were subject to terrestrial runoff. Total litterfall was measured for 389 days and reached a maximum value of 19 t/ha in site B. Fruits comprised up to a quarter part of this production. On average, Rhizophora stands produced 1.8 to 2.5 times more leafy parts than Avicennia stands. Seasonal variations of litter production were much more pronounced in Avicennia stands than in Rhizophora stands. Girth increments averaged 10 times greater for stands at site B than for those at site A. Seasonal variations of girth increments were significantly correlated with rainfall, and it was found that during dry periods growth may be completely arrested. These results are interpreted and discussed at three levels of the spatial organization of the vegetation: site, stand, and species.