Dynamics of tree diversity in undisturbed and logged subtropical rainforest in Australia

In subtropical rainforest in eastern Australia, changes in the diversity of trees were compared under natural conditions and eight silvicultural regimes over 35 years. In the treated plots basal area remaining after logging ranged from 12 to 58 m2 per ha. In three control plots richness differed little over this period. In the eight treated plots richness per plot generally declined after intervention and then gradually increased to greater than original diversity. After logging there was a reduction in richness per plot and an increase in species richness per stem in all but the lightest selective treatments. The change in species diversity was related to the intensity of the logging, however the time taken for species richness to return to pre-logging levels was similar in all silvicultural treatments and was not effected by the intensity of treatment. These results suggest that light selective logging in these forests mainly affects dominant species. The return to high diversity after only a short time under all silvicultural regimes suggests that sustainability and the manipulation of species composition for desired management outcomes is possible

Composition of woody species in a dynamic forest-woodland-savannah mosaic in Uganda: implications for conservation and management

Forest¿woodland¿savannah mosaics are a common feature in the East African landscape. For the conservation of the woody species that occur in such landscapes, the species patterns and the factors that maintain it need to be understood. We studied the woody species distribution in a forest¿woodland¿savannah mosaic in Budongo Forest Reserve, Uganda. The existing vegetation gradients were analyzed using data from a total of 591 plots of 400 or 500 m2 each. Remotely sensed data was used to explore current vegetation cover and the gradients there in for the whole area. A clear species gradient exists in the study area ranging from forest, where there is least disturbance, to wooded grassland, where frequent fire disturbance occurs. Most species are not limited to a specific part of the gradient although many show a maximum abundance at some point along the gradient. Fire and accessibility to the protected area were closely related to variation in species composition along the ordination axis with species like Cynometra alexandri and Uvariopsis congensis occurring at one end of the gradient and Combretum guenzi and Lonchocarpus laxiflorus at the other. The vegetation cover classes identified in the area differed in diversity, density and, especially, basal area. All vegetation cover classes, except open woodland, had indicator species. Diospyros abyssinica, Uvariopsis congensis, Holoptelea grandis and all Celtis species were the indicator species for the forest class, Terminalia velutina and Albizia grandbracteata for closed woodland, Grewia mollis and Combretum mole for very open woodland and Lonchocarpus laxiflorus, Grewia bicolor and Combretum guenzi for the wooded grassland class. Eleven of the species occurred in all cover classes and most of the species that occurred in more than one vegetation cover class showed peak abundance in a specific cover class. Species composition in the study area changes gradually from forest to savannah. Along the gradient, the cover classes are distinguishable in terms of species composition and vegetation structure. These classes are, however, interrelated in species composition. For conservation of the full range of the species within this East African landscape, the mosaic has to be managed as an integrated whole. Burning should be varied over the area with the forest not being burnt at all and the wooded grassland burnt regularly. The different vegetation types that occur between these two extremes should be maintained using a varied fire regim

Food supply and chimpanzee (Pan troglodytes schweinfurthii) party size in the Budongo Forest Reserve, Uganda

A central issue in socioecology is the nature of the relationship between an organism's environment and its social structure. In chimpanzees the fission-fusion social system is thought to minimize feeding competition for primary dietary components: ephemeral, dispersed patches of ripe fruit. Intragroup feeding competition is thought to force individuals into small parties. Informal observations in the Sonso region of the Budongo forest had suggested that in this habitat food supply was such that feeding competition was less important in determining grouping patterns than elsewhere. We used data collected on food supply and party sizes over a 4-year period to investigate this suggestion. In accord with theoretical expectation, sizes of foraging parties fluctuated with the size of food patches. However; party sizes showed either negative or no relationship with habitat-wide measures of food abundance. Likewise party sizes showed little relationship to overall measures of food dispersion. For important dietary items, both fruit and leaves had patchy distributions, though the degree of clumping was not strong, and fruit was not more clumped than leaves. Generally, abundant food appeared to be less patchy, and chimpanzees appeared to use more patches as food became more abundant rather than forming larger parties. We suggest that both dispersal and abundance need robe considered when investigating the impact of food supply on grouping patterns, and that the importance of food as a factor in determining chimpanzee grouping patterns declines with increasing levels of abundance

Extent of biodiversity surveys and ranges for endemic species in the Albertine Rift

This article contains data on the estimated ranges of endemic species in the Albertine Rift both currently and under future climate change related to the research article entitled “Conservation of the endemic species of the Albertine Rift under future climate change” (Ayebare et al., 2018) [1]. Biodiversity surveys focused mainly on 5 taxa: birds, mammals, reptiles, amphibians and plants. A combination of line transects, point counts, recce walks, camera traps, visual encounter surveys, qualitative surveys and appropriate capture methods (mist nets, Sherman traps, pitfall traps) were used to survey the different taxa and provide point location data for each species. The biodiversity surveys were conducted by the Wildlife Conservation Society starting in the late 1990s. Additional species data were sourced from individual researchers and institutions.The current and future species ranges were estimated using the Maximum Entropy ‘(Maxent)’ species distribution modeling algorithm. The areas of suitable habitat (current and future) of 162 endemic species for 5 taxa (birds (40), mammals (33), plants (49), reptiles (11), amphibians (29), the extent of occurrence (EOO), area of occupancy (AOO), percentage range contraction due to climate change and to agriculture conversion of suitable habitat for each species are given in Table S1. Threshold geotiffs are also provided for each species modeled and made available at www.albertinerift.org. Keywords: Biodiversity surveys, Albertine Rift, Endemic species ranges, Climate change, Habitat los