Browsing by Author "Mwavua, Edward N."

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    Effects of selective timber harvest on amphibian species diversity in Budongo forest Reserve, Uganda
    (Forest Ecology and Management, 2020) Lukwago, Wilber; Behangana, Mathias; Mwavua, Edward N.; Hughes, Daniel F.
    We studied the effects of forest management on amphibian communities in the Budongo Central Forest Reserve, Uganda. We sampled amphibians from May to August of 2012 in four compartments with different logging and arboricide-treatment histories. We used pitfall traps with drift fences combined with visual encounter surveys to sample amphibians from 36 plots in four 1-km long transects along the Sonso River. From 126 encounters across plots, we recorded 25 frog species belonging to six families and eight genera. Arthroleptidae was the most diverse family represented by 10 species within two genera. Arthroleptis had the highest number of species (six), Ptychadena the second most (five), followed by Leptopelis (four) and Sclerophrys (four). Species composition differed across transects. The unlogged study site possessed the highest species richness, diversity, and evenness, and had the greatest frequency of species encounters. The most heavily logged site had the lowest species diversity and fewest amount of species encounters. This site also had the most dissimilar species composition among sites and was significantly different in species richness compared to the unlogged site. The two moderately logged sites had the second and third most species, and had the most similar species composition to each other. Our study provides data on the amphibian species of a protected site in the Albertine Rift, part of the Eastern Afromontane biodiversity hotspot, and results suggest that the forest management regimes in Budongo have exerted an influence over the amphibian communities after more than 50 years of forest recovery.
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    Population structure and regeneration of multiple-use tree species in a semi-deciduous African tropical rainforest: Implications for primate conservation
    (Forest Ecology and Management, 2009) Mwavua, Edward N.; Witkowski, T.F.
    The conservation of threatened frugivorous primates (e.g. chimpanzees) and birds in the Albertine Rift Ecoregion rainforests requires the conservation of food tree species aided by an understanding of their natural regeneration and population trends. However, little is known of the population structure and regeneration patterns of a wide range of multiple-use tree species in many of these forests. We examined the population structures and regeneration patterns of 15 tree species (including pioneer, non-pioneer and shade-bearers) that are both timber and primate food sources in Budongo Forest Reserve, NW Uganda, by constructing species population size-class distributions (SCDs), and calculating SCD slopes, seedling:juvenile and juvenile:adult ratios. The SCD slopes were used as indicators of population structure, while the slope values were used to summarise, in a single number, the shape of the SCD for a species. Species composition between forest communities varied significantly, suggesting the influence of spatial environmental variations. Nine species had significant positive correlations between seedling and adult densities. Nine species, namely Lasiodiscus mildbraedii, Celtis mildbraedii, Pouteria altissima, Chrysophyllum albidum, Cynometra alexandri, Diospyros abyssinica, Funtumia elastica, Chrysophyllum perpulchrum and Antiaris toxicaria had highly negative SCD slopes spanning 2.47 to 1.1, and juvenile:adult ratios spanning from 5.34 to 1.62. Hence, clearly exhibiting ‘inverse J’ type curves, and suggesting a successful or healthy regeneration pattern. In contrast, both Alstonia boonei and Cordia millenii had weakly negative SCD slopes of 0.25, and juvenile:adult ratios <1; hence a pulsed or discontinuous regeneration pattern and low recruitment. The SCD slopes and juvenile:adult ratios varied between forest communities and historical management practices (HMPs). Most species recruit successfully and continuously over time, and hence have a more stable population structure. However, a discontinuous regeneration pattern for some, reflects unsustainable harvesting, that potentially eliminates seed sources for future generations. Hence, management of the Budongo Forest Reserve requires plans/practices that will enhance and facilitate the recruitment of both the vigorously and poorly regenerating species to ensure sustainable forest development. Preserving some fruiting trees in logged areas will benefit both long-term sustainable timber production and wildlife conservation, by providing food for frugivorous animals that will disperse the seeds.