Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion ...Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston’s (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km<sup>2 </sup>revealed 286 lions (95% CI, 236 - 335) during the wet season, and 196 lions (95% CI, 192 - 200) during the dry season. The density of lions was 9.1/100 km<sup>2 </sup>during the wet season, and 6.3/100 km<sup>2</sup> during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on the distribution of the observed lions to call-back stations. We suggest that the proximity to water sources is important in study design. Further, we suggest that density and population size are useful indices in identifying conservation area priorities and lion coexistence strategies.展开更多
It has been reported that changes to miombo woodland ecosystems through conversion to other land uses alter tree species diversity and soil properties. The aim was to assess whether the Important Value Index (IVI), Sh...It has been reported that changes to miombo woodland ecosystems through conversion to other land uses alter tree species diversity and soil properties. The aim was to assess whether the Important Value Index (IVI), Shannon- Wiener diversity index (H'), and soil chemical properties differ between land uses in the Kibutuka miombo woodland ecosystem. IVI and H' were used to indicate tree species dominance and diversity. Statistical analyses were performed in R software. IVI of Brachystegia was significantly (p Combretum, Milletia, and Diplorhynchus had significantly (p p p p < 0.05) higher in intact forests than in the degraded forest. Degradation seen at a landscape scale for vegetation parameters, but not for soil parameters, indicates that the land use change taking place in the Kibutuka miombo woodland ecosystem is recent and the degradation seen in vegetation is still not reflected in the soil properties.展开更多
文摘Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston’s (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km<sup>2 </sup>revealed 286 lions (95% CI, 236 - 335) during the wet season, and 196 lions (95% CI, 192 - 200) during the dry season. The density of lions was 9.1/100 km<sup>2 </sup>during the wet season, and 6.3/100 km<sup>2</sup> during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on the distribution of the observed lions to call-back stations. We suggest that the proximity to water sources is important in study design. Further, we suggest that density and population size are useful indices in identifying conservation area priorities and lion coexistence strategies.
文摘It has been reported that changes to miombo woodland ecosystems through conversion to other land uses alter tree species diversity and soil properties. The aim was to assess whether the Important Value Index (IVI), Shannon- Wiener diversity index (H'), and soil chemical properties differ between land uses in the Kibutuka miombo woodland ecosystem. IVI and H' were used to indicate tree species dominance and diversity. Statistical analyses were performed in R software. IVI of Brachystegia was significantly (p Combretum, Milletia, and Diplorhynchus had significantly (p p p p < 0.05) higher in intact forests than in the degraded forest. Degradation seen at a landscape scale for vegetation parameters, but not for soil parameters, indicates that the land use change taking place in the Kibutuka miombo woodland ecosystem is recent and the degradation seen in vegetation is still not reflected in the soil properties.
