47 research outputs found

    A multiple-species participatory domestication programme in the Peruvian Amazon: experiences and results to date

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    In 1995, the World Agroforestry Centre (ICRAF) and partners initiated a participatory agroforestry domestication programme in the Aguaytía Watershed and Alto Amazonas province of the Peruvian Amazon. The programme, aimed primarily at conservation-through-use of genetic diversity, began with formal, participatory prioritization, leading to selection of four species: bolaina blanca (Guazuma crinita Martius: Sterculiaceae),capirona (Calycophyllum spruceanum (Bentham) Hooker f. Ex Schumann)), guaba (Inga edulis C. Martius: Leguminosae (Mimosoideae)), peach palm (Bactris gasipaes Kunth: Palmae). Open-pollinated seed of each was collected from farmer-selected mother trees, and used in the establishment of a series of seedling seed orchards / progeny tests, the individual blocks of which were dispersed on lands of individual collaborating farmers. Almost ten years later these trials are beginning to produce seed, the Aguaytían famers have organized themselves into a wood and seed producers’ cooperative, the technology developed is being adopted more widely, and genetic results are becoming available. We describe the programme and its results in detail, with special emphasis on its innovative features. Subsequently, we evaluate success to date in relation both to initial objectives and the programme’s response to the evolving local forestry and development environment. Finally, we consider future priorities

    Priorization of tree species for agroforestry systems in the lowland amazon forests of Peru

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    1 fig. 1 tab. 1 ref. Sum. (En, Es

    Genetic variation in wood density and correlations with tree growth in Prosopis africana from Burkina Faso and Niger

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    • Variation in wood basic density and its correlation with tree growth were investigated at 13 years in a provenance/progeny test of Prosopis africana in Niger. The test included progeny from 256 trees sampled from 24 provenances in the Sahelian ecozone of Burkina Faso and Niger. • Variation in wood density was significant due to provenances and families within provenances. Individual tree heritability was higher for wood density than for growth traits. Provenance means for wood density increased from the more humid to the drier parts of the sample region. Phenotypic correlations indicated that larger trees tended to have denser wood. • Clines suggest that natural populations of P. africana from the drier parts of the sample region have the genetic capacity to produce denser wood, compared with populations from the more humid parts of the region. Correlations and heritability estimates suggest that selection of faster-growing trees may produce a small gain in wood volume but little (if any) gain in density in the subsequent generation. Multi-location provenance/tests are needed to confirm this tentative conclusion.Variation génétique de la densité du bois et corrélations avec la croissance de l'arbre chez Prosopis africana provenant du Burkina Faso et du Niger. •  La variation de la densité du bois et sa corrélation avec la croissance de l'arbre ont été étudiées à l'âge de 13 ans dans un essai de provenances/descendances de Prosopis africana au Niger. L'essai a inclus les descendances de 256 arbres mères provenant de 24 provenances de l'écozone sahélienne du Burkina Faso et du Niger. • La variation de la densité du bois a été significative en relation avec les provenances et les familles à l'intérieur des provenances. L'héritabilité a été plus élevée pour la densité que pour les caractères de croissance de l'arbre. La densité moyenne des provenances a augmenté des sites les plus humides aux sites les plus secs de la région échantillonnée. Les corrélations phénotypiques ont montré que les plus grands arbres ont eu tendance à avoir le bois le plus dense. • Les clines suggèrent que les populations naturelles de P. africana des sites les plus secs de la région échantillonnée ont la capacité génétique de produire du bois plus dense que les populations des sites les plus humides de la région. Les corrélations et les héritabilités estimées suggèrent que la sélection d'arbres à croissance rapide peut produire un faible gain en volume de bois et très peu de gain en densité du bois dans la génération suivante. Des essais de provenance/descendance dans plusieurs sites sont nécessaires pour confirmer cette conclusion provisoire

    The effectiveness of phenotypic selection in natural populations: a case study from the Peruvian Amazon

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    Phenotypic selection is commonly used in agroforestry, both in genetic improvement and as a component of "good practice" in seed collection. In the first case, the aim is to secure genetic gain. In the second case, selection is used to ensure that seed supplies meet given minimum quality standards, or that poor quality sources are avoided. Here we examine the effectiveness of phenotypic selection in natural forest stands of the Amazonian timber and multipurpose tree Calycophyllum spruceanum Benth. We ask (a) whether mother-trees with high estimated annual height and diameter increments had faster growing progeny than mother-trees with low values; (b) whether forked mother-trees tended to have higher proportions of forked progeny than unforked trees; (c) whether spatially isolated mother-trees tend to produce slower growing progeny than mother-trees growing together with conspecifics. In each case, we found no evidence of differences between the respective groups. We offer explanations for these findings and discuss their implications for tree improvement and seed collection

    Genetic variation in tree growth, stem form and mortality of Guazuma crinita in slower and faster-growing plantations in the Peruvian Amazon

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    Guazuma crinita is an important timber tree with a rotation age of 6–12 years in the Peruvian Amazon. A provenance/progeny test containing 200 families from seven locations (provenances) in the Aguaytía watershed of Peru was established in three zones in the Aguaytía watershed that differ in mean annual rainfall and soil fertility. Farmers managed the replications as plantations. Replications were divided into two groups at 24 months: faster- and slower-growing plantations. The faster-growing plantations were thinned at 32 months. The objectives of this paper are to determine if genetic variation in growth traits (tree height, stem diameter) is relatively greater in the faster-growing plantations, and if there are significant differences in tree mortality and stem bifurcations among provenances and families at 24, 36 and 48 months. Variation due to provenances and families and heritability of growth traits were consistently greater in the faster-growing plantations. At 48 months, heritability of growth traits was about twice as large in the faster- than in the slower-growing plantations. There were no significant interactions between zones and either provenances or families. Tree mortality and stem bifurcations in the faster-growing plantations generally did not differ significantly among families, but did differ significantly among provenances. Based on these results and considering its rotation age, we recommend that G. crinita families/trees could be selected at 48 months in the faster-growing plantations, the plantations could be transformed into seed orchards and the seed could be used for reforestation throughout the Aguaytía watershed. Results are compared with other tropical hardwoods

    The history of ecosystem services in economic theory and practice: From early notions to markets and payment schemes

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    This paper reviews the historic development of the conceptualization of ecosystem services and examines critical landmarks in economic theory and practice with regard to the incorporation of ecosystem services into markets and payment schemes. The review presented here suggests that the trend towards monetization and commodification of ecosystem services is partly the result of a slow move from the original economic conception of nature's benefits as use values in Classical economics to their conceptualization in terms of exchange values in Neoclassical economics. The theory and practice of current ecosystem services science are examined in the light of this historical development. From this review, we conclude that the focus on monetary valuation and payment schemes has contributed to attract political support for conservation, but also to commodify a growing number of ecosystem services and to reproduce the Neoclassical economics paradigm and the market logic to tackle environmental problem
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