Gerald Eilu

Traditional farming and plant species diversity in agricultural landscapes of south-western Uganda

An effort was undertaken in Bushwere Parish (Mbarara district, south-western Uganda) between 1999 and 2000 to develop sustainable and participatory approaches to plant biodiversity conservation at the farm level. One hundred farmers were interviewed on their socio-economic profiles and plant use strategies. Plant diversity was assessed in 400 plots of 5 m × 5m established in 53 field types of seven land-use categories. The most species-rich land-use category was under annual crops (149 plant species) while the most species-rich field type was planted with bananas (118 species). Shannon diversity and Sorensen’s similarity indices were used to compute species diversity and similarity, respectively, between field types and land-uses. The most plant diverse land-use was natural woodland, the least fallow. Canonical correspondence analysis (CCA) showed that occurrence of species, field type or land-use depended upon environmental factors such as elevation, position on the slope and soil type. Redundancy analysis (RDA) showed that species utility and occurrence were related to the socio-economic status of farmers. Plant species were most diverse in land-uses located on hill tops and steep slopes. Farmers should therefore be advised on how to maintain plant diversity in agricultural landscapes.

Traditional management and conservation of shea trees (Vitellaria paradoxa subspecies nilotica) in Uganda

Traditional practices are universally recognised as a basis for conservation of biodiversity. However, such practices are often not included in natural resource conservation policies. This study assessed local conservation practices of shea trees (Vitellaria paradoxa) within different farming systems in Uganda and developed conservation guidelines for the species. The assessment involved 300 respondents, 15 focus groups and 41 key informants. Content analysis was used to identify the most important management and conservation practices. Local uses were categorised on the basis of shea tree products while differences in conservation practices were analysed using the Friedman test. The results show that eight shea tree products are used for 36 different purposes. Respondents’ age significantly influenced their knowledge about the shea tree. Traditional conservation practices include on-farm retention during cultivation and the use of folklore (mainly taboos), customs and rituals. Traditional management practices include weeding, bush burning, pollarding and pruning. Based on the current management and traditional conservation practices, a framework for the conservation of shea trees is proposed for integration into conservation policy decisions.

Strategies for empowering the local people to participate in forest restoration

Within various parts of the tropics and temperate regions, there are increasingly more efforts towards reforestation or restoration. Interventions in the tropics however, have not adequately addressed the needs of local people compelling them to degrade forests. We conducted a study in and around Mabira Forest Reserve in Uganda with the aim of assessing locally proposed restoration techniques and conditions for empowering local people to raise their willingness to participate in forest restoration practices. We specifically set out to; (i) identify proposed techniques to restore the degraded forests, and (ii) determine the pre-conditions for supporting local people’s participation in restoration activities. Data were collected using individual semi-structured interviews, focus group discussions and participatory forest surveys. The findings show that the local people mainly engaged in practices that address their needs concurrently. The most reported practices include: planting trees on farm, enrichment tree planting in the forest, control of soil erosion, and control of invasive alien species. The main pre-conditions for their participation in forest restoration is assurance for more access to forest resources. The efficiency of local people in restoration will be enhanced by strengthening their capacity for collaborative forest management, raising their awareness on restoration, building their capacity, as well as continuous monitoring by forest managers.

Wildlife Snaring in Budongo Forest Reserve, Uganda

Snaring is an indiscriminate vertebrate trapping method that has maimed more than 36% of an estimated 700 resident chimpanzees (Pan troglodytes) of Budongo Forest Reserve. This study was conducted in two phases to assess this problem. First, we administered questionnaires to 240 randomly selected households in villages around the reserve to look at socioeconomic and cultural contexts within which snares are set. Second, hunters identified in the first phase were purposefully selected for deeper discussions into snaring; 12% of the farmers set snares. Logistic regression showed a significant relationship between snaring and socioeconomic variables such as education. Hunters considered bushmeat an integral part of their livelihood and thus, snaring may continue or increase from current levels. Alternative sources of protein and cash for local people will be necessary to offset snaring problems. Conservationists need to address in-forest diversity and strategies that improve food security and income for forest edge communities.

Fat content and fatty acid profiles of shea tree (#Vitellaria paradoxa# subspecies #nilotica#) ethno-varieties in Uganda

Fat content and fatty acid composition are important nutritional properties of shea fruits. Farmers in Uganda report the presence of local shea tree ethno-varieties, but it is necessary to investigate their relative fat content and fatty acid composition to evaluate the economic importance of these ethno-varieties. Near infrared spectrophotometry (NIRS) was used to determine the fat content as well as the fatty acid composition of 44 ethno-varieties. Wet chemistry (soxtec petroleum – ether fat extraction and gas chromatography) methods were used to validate the results from NIRS. Fat content ranged from 43.9% to 58.4% while fatty acid composition was dominated by oleic (47–62%) and stearic acid (25–38%). Other fatty acids present were palmitic, vaccenic, linoleic, linolenic and arachidic acids. There was no significant difference in stearic, palmitic and oleic acid composition between ethno-varieties. However, significant variation of fat content, vaccenic and linoleic acids was observed between some ethno-varieties, perhaps due to locality, climatic and tree-to-tree differences. These findings can be utilized for the selection of ethno-varieties that are suitable for commercial production of shea oil in Uganda.

Genetic diversity in shea tree (Vitellaria paradoxa subspecies nilotica) ethno-varieties in Uganda assessed with microsatellite markers

Shea trees (Vitellariaparadoxa C. F. Gaertn.) are classified locally into several folk or ethno-varieties by farmers in Uganda. It is, however, not clear whether this folk classification is supported by genetic differentiation between ethno-varieties. Genetically linked traits from folk classification are useful in conservation and breeding programmes. A total of 118 individual shea trees constituting 28 ethno-varieties sampled from three farming systems of Uganda were analysed using microsatellite markers. The number of alleles amplified per microsatellite locus ranged from 6 to 13 with an average of 9.5, with a total of 106 alleles identified. Observed (Ho) and expected heterozygosity (He) per locus ranged from 0.366 to 0.934 and 0.580 to 0.840, respectively. Mean Ho and He values for all loci across all ethno-varieties were 0.633 and 0.727, respectively. Analysis of molecular variance indicated that most of the variation (86.28%) occurred within individual trees; 11.25% was found among individual trees within ethno-varieties while 2.47% was found among ethno-varieties. The in-breeding index (f = 0.130), fixation index (θP = 0.025), gene flow value (Nm = 6.56) and cluster analysis show that all shea tree ethno-varieties were a single out-crossing population with very low genetic differentiation and high gene flow. The low differentiation in shea tree ethno-varieties was most likely due to the utilization of non-genetic traits in folk classification. However, while ethno-variety genetic structure was very weak, overall spatial population structure indicated the presence of three populations (West Nile, Northern and Teso). The West Nile population was more distantly related to the other two most likely due to isolation barriers such as the Rift Valley, Lake Albert and River Nile.

Sweet vernal grasses (Anthoxanthum) colonized African mountains along two fronts in the Late Pliocene, followed by secondary contact, polyploidization and local extinction in the Pleistocene

High tropical mountains harbour remarkable and fragmented biodiversity thought to a large degree to have been shaped by multiple dispersals of cold‐adapted lineages from remote areas. Few dated phylogenetic/phylogeographic analyses are however available. Here, we address the hypotheses that the sub‐Saharan African sweet vernal grasses have a dual colonization history and that lineages of independent origins have established secondary contact. We carried out rangewide sampling across the eastern African high mountains, inferred dated phylogenies from nuclear ribosomal and plastid DNA using Bayesian methods, and performed flow cytometry and AFLP (amplified fragment length polymorphism) analyses. We inferred a single Late Pliocene western Eurasian origin of the eastern African taxa, whose high‐ploid populations in one mountain group formed a distinct phylogeographic group and carried plastids that diverged from those of the currently allopatric southern African lineage in the Mid‐ to Late Pleistocene. We show that Anthoxanthum has an intriguing history in sub‐Saharan Africa, including Late Pliocene colonization from southeast and north, followed by secondary contact, hybridization, allopolyploidization and local extinction during one of the last glacial cycles. Our results add to a growing body of evidence showing that isolated tropical high mountain habitats have a dynamic recent history involving niche conservatism and recruitment from remote sources, repeated dispersals, diversification, hybridization and local extinction.

Forest disturbance and cropping mixtures influence crop raiding by red-tailed monkey and grey-cheeked mangabey around Mabira Forest Reserve, Uganda.

Communities around protected areas frequently complain of wild animals destroying already limited crop fields, with little or no assistance offered by conservation stewards towards the mitigation of crop raiding losses. The aim of this study was to find out whether forest disturbance gradient and crop mixtures influence the level of crop raiding by the red-tailed monkey (Cercopithecus ascanius larvatus) and the grey-cheeked mangebey (Lophocebus ugandae). The study was conducted in sample plots from seven village enclaves surrounding the Mabira Forest Reserve in central Uganda. Crop raiding was highest in the maize-cassava (Zea mays-Manihot esculenta) and least in banana-coffee (Musa sp.Coffea sp.) cropping mixtures. Crop raiding among disturbance zones was higher in the more disturbed production zone, but did not differ between the low and moderate disturbance zones (nature reserve and recreation buffer). Results show that crop raiding by the two primate species is enhanced by forest disturbance that encourage either very limited or extensive forest disturbance. However, the gravity of crop raiding is also determined by the cropping systems practices by communities around the forest. Planting mixtures of highly susceptible crops such as maize and less susceptible ones such as coffee, as well as following recommended weeding regimes can reduce the level of raiding. Compensation schemes should be disaggregated according to disturbance (or management zones).

Mineral composition of Tamarindus indica LINN (tamarind) pulp and seeds from different agro‐ecological zones of Uganda

Abstract Mineral composition of dry Tamarindus indica LINN pulp and seeds was evaluated on samples collected from three different agro‐ecological zones of Uganda (Lake Victoria Crescent, and Eastern and West Nile). The objective of the study was to evaluate the mineral composition of T. indica pulp and seed samples from across Ugandas different agro‐ecological zones and land use types. Separately grounded samples of T. indica pulp and seeds were analyzed for Zn, Fe, Mg, P, Na, K, and Ca. The univariate analysis of variance in the General Linear Model was used to compare differences in mineral composition. Treatment means were separated using Least Significant Difference (LSD) in Post Hoc Tests. The results showed that there were significant differences (p ≤ 0.005) in mineral composition levels of T. indica pulp and seed samples between the different agro‐ecological zones with the exception of P and Na (for pulp). The T. indica pulp and seeds samples from the Lake Victoria Crescent zone and wild land use type had generally higher mineral levels than T. indica samples from other agro‐ecological zones and different land use types. As mineral composition levels were generally higher in the seed than the pulp samples, consumption of T. indica seeds should be promoted. There is also need to conserve individual species both on‐farm and in the wild population, but T. indica mineral concentrations (both pulp and seeds) were higher in the samples from the wild population, making them good for human and animal diets.

Detection of Self Incompatibility Genotypes in Prunus africana: Characterization, Evolution and Spatial Analysis.

In flowering plants, self-incompatibility is an effective genetic mechanism that prevents self-fertilization. Most Prunus tree species exhibit a homomorphic gametophytic self-incompatibility (GSI) system, in which the pollen phenotype is encoded by its own haploid genome. To date, no identification of S-alleles had been done in Prunus africana, the only member of the genus in Africa. To identify S-RNase alleles and hence determine S-genotypes in African cherry (Prunus africana) from Mabira Forest Reserve, Uganda, primers flanking the first and second intron were designed and these amplified two bands in most individuals. PCR bands on agarose indicated 26 and 8 different S-alleles for second and first intron respectively. Partial or full sequences were obtained for all these fragments. Comparison with published S-RNase data indicated that the amplified products were S-RNase alleles with very high interspecies homology despite the high intraspecific variation. Against expectations for a locus under balancing selection, frequency and spatial distribution of the alleles in a study plot was not random. Implications of the results to breeding efforts in the species are discussed, and mating experiments are strongly suggested to finally prove the functionality of SI in P. africana.