Tree population studies in low-diversity forests, Guyana. II. Assessments on the distribution and abundance of non-timber forest products

摘要

Comparisons between two forest localities were undertaken to assess the potential availability of non-timber forest products (NTFPs) within the low-diversity forests of Guyana. The locations were at Kurupukari on the Essequibo river (within the study area of the International Iwokrama Rain Forest Programme) and Moraballi Creek near Bartica on the Essequibo river. Information on the abundance and distribution of tree species, and local and national ethnobotanical surveys were used classifying species into five categories (timber, construction, technological, edible, and medicinal). A total of 152 species was recorded from the two localities, covering 236 different uses, 33 known commercial timber species and 106 species with potential non-timber product utilization. The most important plant families with the highest number of uses at both localities were Leguminosae (subfamilies Caesalpinioideae and Mimosoideae), Arecaceae, Bombacaceae and Chrysobalanaceae, although these families were not the most abundant families at both localities. At both forest localities eight tree species represented over 50% of all the trees. At Kurupukari three species, each with more than three identified NTFPs, represented over 20% of the trees. Potential utilizationof NTFPs are discussed in accordance with species richness, tree density, the number of different uses per species, and the percentage of trees represented by each utilizable species. Considering the constraints on the future potential commercializationof NTFPs, two scenarios for the extraction of NTFPs are discussed. Within relatively species-rich forest types the high diversity of products provides potentially viable multiple-species extractionism. In contrast, in low-diversity forest types, typicalof the Guiana Shield, one or two NTFP species frequently represent over 50% of the canopy trees, and therefore substantially increase the potential sustainable extraction for single-species harvesting. It is suggested that these low-diversity types of forest are prioritized for conservation on the basis of ensuring future utilization, refuge, of non-timber forest products.