Spatial and Temporal Patterns of Abundance and Diversity of an East African Leaf Litter Amphibian Fauna

We present data on sample richness, relative abundance, and community structure of a leaf litter amphibian assemblage from globally important miombo-mopane woodlands characteristic of western Tanzania. We describe patterns of diversity across major habitat types and between different seasons from an annual pitfall-trapping campaign. We recorded 28 species of amphibians, which is significantly higher than existing richness estimates for other miombo woodland sites elsewhere in sub-Saharan Africa. We found that cultivation of native habitat reduces frog diversity, a conclusion that has important implications in light of the rapid conversion of miombo woodland for agriculture and fuel-wood across much of southern and central Africa. Many species showed strongly ansynchronized patterns of seasonality in relative abundance, which has significant implications for the establishment of successful monitoring programs and biodiversity surveys. These conclusions emphasize the importance of stratified long-term sampling in biodiversity studies and demonstrate that superficial levels of sampling effort can lead to erroneous conclusions regarding patterns of diversity in amphibian communities. The relatively poor focus on herpetofaunal research in African miombo-mopane woodland is out of proportion to its ecological and conservation significance.     

A reassessment of the fire‐tolerance of some miombo woody species in the Central Province,Zambia

The fire‐tolerance of 21 woody species in a dry miombo woodland in the Central Province, Zambia was evaluated and compared to an existing classification. The evaluation is based on differences in the vertical distribution of canopy volumes over a range of height intervals after repeated exposure of woodlands to fire. Woody species that showed an inverse correlation between canopy volume and tree height were classified as fire‐sensitive, whilst those that showed a positive correlation were classified as fire‐tolerant. A new method of a rapid and simple field evaluation is described, and further applications are discussed.     

The effects of human disturbance on the species composition,species diversity and functional diversity of a Miombo woodland in northern Malawi

Anthropogenic disturbances have serious impacts on ecosystems across the world. Understanding the effects of disturbance on woodlands, especially in regions where local people depend on these natural resources, is essential for sustainable natural resource management and biodiversity conservation. In this study, we evaluated the effects of anthropogenic disturbance, specifically selective logging of Brachystegia floribunda, on woodlands by comparing species composition, species diversity and functional diversity of woody plants between disturbed and undisturbed woodlands. We combined species data and functional trait data for leaves, fruits and other traits related to resource and disturbance responses to calculate functional indices (functional richness, evenness and divergence) and community‐weighted means of each trait. Shifts in taxonomic species composition were analysed using nonmetric multi‐dimensional scaling. Species composition differed significantly between disturbed and undisturbed woodlands. Tree density was greater in disturbed woodlands, whereas evenness, functional evenness and functional divergence were greater in undisturbed woodlands. In terms of forest cover, selective logging of B. floribunda appeared to have little impact on Miombo woodlands, but some shifts in functional traits, such as the shift from a deciduous to evergreen phenology, may increase the vulnerability of these ecosystems to environmental change, especially drought.     

Land use changes and conservation threats in the eastern Selous–Niassa wildlife corridor,Nachingwea, Tanzania

Selous–Niassa miombo woodland ecosystem has been and continues to face conservation threats. Understanding of changes happening in such ecosystem overtime is important for establishing management baseline data. This study identified land use changes, socio‐economic factors and conservation threats to the Selous–Niassa wildlife corridor across Nachingwea district, Tanzania. Landsat images of 1978, 1993 and 2000 were used to assess land use changes. Household survey was conducted to obtain socio‐economic data; logistic regression model was used to analyse the data. In 15 years (1978–1993) cultivated land only increased by 131% while forestlands decreased by 8.7%. In 12 years (1993–2005) cultivated land increased by 65.6% while forestland decreased by 10.7%. Land cover change per year has been found 0.54% relatively low compared to national land cover change of 45%per year. Land tenure, shifting cultivation and crops prices were major factors influencing land use changes while wildfires, farm encroachment and illegal timber harvesting were major conservation threats. Basing on the results, it was recommended that there is a need for a government to introduce community‐based natural resource management plans to improve natural resource utilization and reduce human stress to the corridor.     

Densities of mammals in partially protected areas: the Katavi ecosystem of western Tanzania

1. In Africa the majority of conservation areas sanction some sort of human activities within their borders but few of them are part of community-based conservation schemes. The effectiveness of these state-owned, partially protected areas in conserving mammalian fauna is largely unknown.
2. Large and medium-sized mammal densities in three different sorts of partially protected area were compared to mammal densities in an adjacent national park in western Tanzania by driving 2953 km of strip transects over a 14-month period.
3. In a Game Controlled Area that permitted temporary settlement, cattle grazing and tourist big game hunting, mammal diversity and mammal densities were relatively high. In a Forest Reserve that permitted limited hardwood extraction and resident hunting, most large species were absent. In a third, Open Area that allowed settlement, cattle grazing, firewood collection and beekeeping activities, mammal diversity and densities were again low but some large ungulates still used the area seasonally.
4. The chief factors responsible for lowered mammal densities outside the Park were illegal hunting, especially in close proximity to town, and to a lesser extent, resident hunting quotas that were too high.
5. These data suggest that state-owned conservation areas permitting human activities within their borders cannot be relied upon as a means of conserving large and middle-sized mammals in Africa.
6. Two methods are being employed to ameliorate this problem in Africa: excluding people from conservation areas while upgrading ground protection effort, and initiation of community-based conservation schemes. As yet, however, very few quantitative data are available to evaluate the efficacy of these methods in enhancing mammal populations.