Dataverse World Agroforestry (ICRAF)
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Replication data for: Genetic variation in tree growth, stem form and mortality of Guazuma crinita in slower- and faster-growing plantations in the Peruvian Amazon
No full textGuazuma crinita is an important timber tree with a rotation age of 6 to 12 years in the Peruvian Amazon. A provenance/progeny test containing 200 families from seven locations (provenances) in the Aguaytia watershed of Peru was established in three zones in the Aguaytia 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 Aguaytia watershed. Results are compared with other tropical hardwoods
Morphological characteristics of Chrysophyllum albidum fruits and seeds in Nigeria
No full textThis study was carried out to characterised Chrysophyllum albidum fruit and seed in Nigeria. This data was collected in 11 local governments whereby the following parameters were measured: fruit weight, fruit length, fruit width and number of kernel
Influence of indigenous tree presence on soil macrofauna and soil organic matter dynamics in tropical agricultural landscapes
No full textAbstract Trees in farmlands contribute to soil organic matter levels through leaf litter additions and root turnover. Trees also play important roles in the improvement of nutrient cycling and a more efficient utilization of existing soil nutrients as well as those externally applied. Soil macrofauna distribution is influenced by spatial variability of organic resources as they
are influenced by land use and climate. There is limited information available on the effect of trees on the spatial distribution of soil macrofauna activity in agricultural landscapes. This study was therefore undertaken to understand the influence of indigenous trees, land use and soil moisture on soil macrofauna as related to changes in soil physical and chemical properties. The soil macrofauna study was conducted at the Kiberashi Sentinel Site, Tanzania (AfSIS), following the LDSF nested sampling design across a total area of 100 square kilometers. A total of six-hundred and forty (640) monoliths (25 x 25 x 10 cm) were collected, soil macrofauna separated by hand sorting, and soil samples prepared for spectroscopic analyses. Organisms were not identified to species and only the main taxa were considered. In the laboratory, organisms were separated into seven broad groups (earthworms, termites, ants, beetles, millipedes, centipedes and âother invertebratesâ). Density and biomass of each of these groups were determined in each of the soil monoliths. Mid-Infrared (MIR) Spectroscopic analyses and soil textural analysis were used to characterize monolith soils inhabited by soil macrofauna. Earthworms, centipedes, millipedes and beetles showed significant clustering, while termites and ants did not. Moisture conditions influenced the distribution of earthworms and beetes. Soil total C, pH, available P, clay content and exchangeable bases explained close to 80% of the variation in soil properties. High abundance of beetles and lower abundance of earthworms and centipedes were found in soils of higher pH, while higher C soils had lower abundance of beetles and termites. Higher abundance of termites was found in soils with high clay content
Replication Data for: Influence de la provenance des geniteurs et du type pollen sur la fructification sous pollinisation controlee chez Dacryodes edulis (Burseraceae)
No full textVery little work has been done on the breeding of native species. Domestication requires germplasm improvement that may lead to the achievement of improved planting material for the creation of new ciltivars. Controlled cross-pollination tests were conducted on Dacryodes edulis (Burseraceae) in order to assess the influence of the provenance and the pollen type on the fruit production of 14 females accessions belonging to 09 families from 03 provenances. the crosses were performed according to a 'nested design block' in which the two types of pollen from a given provenance were used to fertilize a group of 05 female trees from the same provenance. For each cross, the number of pollinated flowers, number of fruits set and the number of mature fruits were evaluated; the fruit setting rate (TN), the fruiting index (FI) and the fruit dropping rate (TC) were calculated and subjected to analysis of variance. Based on averages, different combinations were classified according to their performance using the 'cluster analysis'. The result showed that the fruiting index that determines the studied species 'yield varies only and significantly (p=0.01.) under the combined action of the three factors studied : the provenance, the female parent in the provenance and the type of pollen used in the crosses
Replication data for: Characterisation morphologique des fruits de Dacryodes macrophylla en zone forestiere humide du cameroun
No full textThe study was carried out to determine the morphological characteristics of the fruit of Dacryodes macrophylla. 15 trees were sampled containing 285 seeds. Parameters measured were: the fruit diameter, fruit width, fruit thickness, grain thickness, pulp thickness and colour of pulp
Replication data for: Morphological variation in Balanites aegyptiaca fruits and seeds within and among parkland agroforests in eastern Niger
No full textBalanites aegyptiaca (L.) Delile. is one of the priority indigenous fruit trees for rural communities in the West African Sahel. As part of a participatory tree omestication program in Niger, phenotypic variation in fruit and seed morphology was assessed in four natural populations in eastern Niger. Measured variables were weight of the fruit, seed coat and kernel; length and width of the fruit and seed (25 trees per population, 30 fruits per tree). Derived variables were the tree’s coefficient of variation (CVs) for each measured variable, and two sets of factor scores from principal compo
nents analysis of tree means and CVs. ANOVA indicated significant variation in all measured variables due to trees nested in populations. ANOVA and simple linear regression indicated significant geographic variation in some ariables: the drier parts of the sample region tended to have heavier fruits and kernels, longer/narrower seeds, and lower within-tree variability in fruit and seed width. Length and width were strongly correlated between fruits and seeds, fruit weight was moderately correlated with seed dimensions, and CVs of fruit weight and width were moderately correlated with the CV of seed width. Some hypotheses for the geographic variation are presented, and some practical implications of the correlations for tree domestication programs are discussed
ASB Africa Biocarbon database
No full textThe African continent is the least emitter of Green House Gases (GHG), but the most vulnerable to the effects of climate change. Bio-carbon projects hold a great promise for the continent to contribute to climate change mitigation, while adapting. The projects also yield additional socio-economic and environmental benefits which are important to the local communities around the areas where the projects are implemented. The database takes stock of afforestation/reforestation as well as agricultural projects in Africa that contribute to carbon sequestration. The key items of the database include; 1. Project name, 2. Country, 3. Inve
stor, 4. Amount invested (US$), 5. Implementer, 6.Type (Agriculture/Forestry), 7. Amount of Carbon offset, 8. Project Start year and end Year, 9. Status of development of the project, 10. Mechanism under which the project was initiated, 11. Area of carbon sequestration, 12 Best practices in community based programmes and smallholder farmer involvement, 13. Framework for benefit sharing, 14 Data sources. The key findings were: 1) Africa has more than 100 bio-carbon projects, ranging from forest conservation to agroforestry, as well as many sustainable land management programmes, but most of them are at an infant stage, with less than 5% generating financial benefits to local communities. 2) The continent is seriously lagging behind other continents in terms of participation in the Clean Development Mechanism (CDM), REDD, and voluntary carbon markets and if current investment patterns continue, the world will miss important opportunities to maximize emission reductions in economically poor but natural resource rich countries in Africa
Optimum Pruning Strategies for Reducing Crop Suppression in a gmelina-maize Smallholder Agroforestry System in Claveria, Philippines
No full textOn-farm trials were conducted to assess the effects of four branch pruning levels on maize grain yield, tree growth and stem shape. The experimental plots consisted of gmelina (Gmelina arborea R.Br.) trees planted at 1 x 10 m with maize intercropped in the 10 m-wide alleys between lines of trees. Pruning levels consisted of retaining a live crown ratio of 60-Â70% (T1), 40-50% (T2); 30-40% (T3) and of 20-30% (T4). At the end of the experiment, the total maize grain yield was highest under the high pruning intensity (T4) (18.06 t ha-1) and lowest under T1 (14.48 t ha-1). Maize grain yield under the pruning regime T2 and T3 were 16.08 and 17.21 t ha-1 respectively. Mean annual increment (MAI) in tree diameter was greater (5.0 cm yr-1) under T1 than those at T4 (4.1 cm yr-1). Pruning regimes T2 and T3 resulted in a MAI of 4.7 cm yr-1 and 4.5 cm yr-1 respectively. Financial analysis showed that maize-tree systems under T4 were more profitable than under T1 as long as the reduction of the average dbh at harvest were not greater than 1 cm. Pruning trees intensively also generated greater returns from labour than moderate pruning, as the greater maize grain yields under T4 compen
sated for the cost of pruning and the lower timber yield. In the context of resource-poor farmers, intensive branch pruning was a practice that prolonged the period of profitable intercropping and was compatible with commercial timber production
Replication data for: Impact of forestland tenure changes on forest cover, stocking and tree species diversity in Amani Nature Reserve, Tanzania
No full textThe aim of the present study was to evaluate the impact of changes from private to state tenure on forest resources for three blocks in Amani Nature Reserve. The resource changes were determined in terms of forest cover, forest stocking and tree species diversity over a period of six to eight years. When considering the three blocks as one entity one may in general maintain that there have been positive changes regarding forest cover. There were differences between the blocks, however. The proportions of dense and semi-closed forest increased by around 14% in the former tea company block, remained unchanged in the former farmland and decreased by around 12% in the former sisal company block. The changes in stocking parameters and tree species diversity were mainly positive, but none were statistically significant. Although the results were somewhat ambiguous evidence of positive impacts as a result of the tenure changes was identified. This is in line with the main aim of establishing nature reserves focusing on conservation values. More research, however, is required regarding impacts of tenure changes on livelihood for those living adjacent to the nature reserve
Viability of resource centres in the vulgarisation of agroforestry innovations in Cameroon: Case of CIMAR and CIEFAD resource centres
No full textCertaines Organisations Relais utilisent lâapproche « Centre de Ressources » pour diffuser les innovations agroforestières. Or, la mise en place de cette approche est un processus progressif qui nécessite un engagement soutenu de ses promoteurs et des investissements importants. Cette étude
a pour objectif dâexaminer si et sous quelles conditions cette approche peut assurer la vulgarisation agroforestière dans le temps. Elle se propose dâanalyser les facteurs qui déterminent la viabilité des centres de ressources dans la diffusion des innovations agroforestières. Câest pour répondre à ce problème que nous avons effectué une étude de six mois dans le Département du Ndé (Bangangté et ses environs) et du Moungo (Njombé et ses environs) qui sont tous deux des sites pilotes de lâICRAF. Pour mener cette étude, les données primaires ont été collectées à trois niveaux. Le premier niveau était constitué des Organisations Relais (OR) et des Centres de Ressources (CR) dans les sites dâétude à raison de deux OR et deux CR. Ensuite, le deuxième niveau était celui des groupes de producteurs encadrés par les Centres de Ressources. Le troisième niveau était les autres parties prenantes. Lâanalyse de ces informations montre tout dâabord que le nombre dâespèces domestiquées varie de 26 à 27. Le semis étant la méthode la plus utilisée pour multiplier les arbres. Les bénéfices moyens annuels varient de 6.720.373 FCFA à 20.687.297 FCFA et les bénéfices nets de 2.376.407 FCFA à -2.260.509 FCFA. Ce qui signifie que les CR ne sont pas rentables et ne sont capables de sâautofinancer que sâils créent des recettes supplémentaires, entre autre lâorganisation des colonies de vacances et la formation en environnement dans les établissements scolaires. Enfin, la notation de la qualité de formation technique par les groupes varie entre 8 et 9, tandis que la qualité organisationnelle a été notée 7,8 et 8,5 pour CIEFAD et CIMAR respectivement. De même, la notation de la qualité des produits par les autres parties prenantes varie de 8,66 à 9. Tous les groupes affirment nâavoir reçu aucun appui financier du CR. Or de façon générale, les producteurs sont satisfaits du travail que mènent les Centres de Ressources dans leur localité respective, bien quâils suggèrent un suivi des groupes plus accentué et la recherche des débouchés pour lâécoulement des produits. Lâétude recommande au gouvernement Camerounais dâencourager les centres de ressources dans la diffusion des innovations agroforestières en organisant des programmes de développement qui leur permettront de bénéficier des subventions et des dons