Faeces from naturally infected goats were deposited on a natural grassland during the dry season in Guadeloupe (French West Indies) at different times throughout the day. The grass was either 7 or 20-30 cm tall. After a period of between several hours and 7 days, the number of viable strongyle eggs and the faecal water content were measured. Faecal temperature was recorded continuously. Faecal temperature was greater than 40 degrees-45 degrees C at midday and dehydration was rapid between 8 a.m. and 2 p.m. Egg mortality was greater on short than on tall grass and higher in morning than in evening deposits. Minimal faecal water content during the first 36 h explained the 74%, 55% and 38% mortality rate for eggs of Oesophagostomum columbianum (OC), Haemonchus contortus (HC) and Trichostrongylus colubriformis (TC), respectively. In all, 5%-22% of the eggs of the latter species remained viable in a state of anhydrobiosis after 7 days on the ground. A delay of only 2 days between goat departure and irrigation would be sufficient to ensure that greater than 95% of O. columbianum and H. contortus eggs and 70% of T. colubriformis eggs are destroyed.

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BackgroundIn many geographic areas influenced by tropical and temperate climates, natural forest ecosystems have been destroyed in favour of plantations of allochthonous trees which are economically profitable for different aspects of the timber industry. Some of these mature plantations degrade the soils and inhibit the regenerations of local flora species; others, due to the physical constraints which they impose, can contribute to the installation and the morphogenetic development of autochthonous taxa. The plantations of Swietenia macrophylla and Swietenia aubrevilleana (Mahoganys) in the Lesser Antilles are part of these processes. MethodsTo study the regeneration methods of forest plant species native to Martinique under plantations of Mahoganys, we carried out surveys in thirteen transects (stations) influenced by humid and subhumid bioclimates. ResultsThe results showed that affine natural flora species from various stages of the plant succession colonise the plots of mature Mahoganys. ConclusionsThis study shows that mature plantations of not very competitive introduced forest species can greatly accelerate phytocenotic succession and increase specific richness. It is therefore possible to use these introduced species (Swietenia macrophylla and Swietenia aubrevilleana) in reforestation processes of Lesser Antilles biotopes of sylvan potentiality degraded by anthropisation.

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