Search

The response of terrestrial vegetation to a globally changing environment is central to predictions of future levels of atmospheric carbon dioxide (1,2). The role of tropical forests is critical because they are carbon-dense and highly productive (3,4). Inventory plots across Amazonia show that old-growth forests have increased in carbon storage over recent decades (5-7), but the response of one-third of the world's tropical forests in Africa (8) is largely unknown owing to an absence of spatially extensive observation networks (9,10). Here we report data from a ten-country network of long-term monitoring plots in African tropical forests. We find that across 79 plots (163 ha) above-ground carbon storage in live trees increased by 0.63 Mg C [ha.sup.-1] [yr.sup.-1] between 1968 and 2007 (95% confidence interval (CI), 0.22-0.94; mean interval, 1987-96). Extrapolation to unmeasured forest components (live roots, small trees, necromass) and scaling to the continent implies a total increase in carbon storage in African tropical forest trees of 0.34 Pg C [yr.sup.-1] (CI, 0.15-0.43). These reported changes in carbon storage are similar to those reported for Amazonian forests per unit area (6,7), providing evidence that increasing carbon storage in old-growth forests is a pan-tropical phenomenon. Indeed, combining all standardized inventory data from this study and from tropical America and Asia (5,6,11) together yields a comparable figure of 0.49 Mg C [ha.sup.-1] [yr.sup.-1] (n = 156; 562 ha; CI, 0.29-0.66; mean interval, 1987-97). This indicates a carbon sink of 1.3 Pg C [yr.sup.-1] (CI, 0.8-1.6) across all tropical forests during recent decades. Taxon-specific analyses of African inventory and other data (12) suggest that widespread changes in resource availability, such as increasing atmospheric carbon dioxide concentrations, may be the cause of the increase in carbon stocks (13), as some theory (14) and models (2,10,15) predict., Tropical forests cover 7-10% of the global land area, store 40-50% of carbon in terrestrial vegetation and annually process approximately six times as much carbon via photosynthesis and respiration as [...]

This study reports on the forest avifaunas of Ihang’ana and Idewa Forest Reserves, located on the Udzungwa Plateau, Tanzania, which are undocumented in published literature. Field surveys were conducted between 28 October and 6 November 2020 using the McKinnon species list method. From 185 McKinnon 10-species lists, 40 species were observed in Ihang’ana and 30 in Idewa Forest Reserves, for a combined total of 41 species. Of the species recorded, over 78% (32 species) were forest-dependent birds representative of Eastern Arc Mountains forests. Seven species detected are considered restricted-range species, including Yellow-throated Greenbul Arizelocichla chlorigula, which is endemic to the Eastern Arc Mountains of Tanzania. The results suggest that forest birds, including montane species, can survive in isolated areas of suitable habitat even when patch size is small. As such, forests such as Ihang’ana and Idewa forests can still play an important role in the conservation of forest birds. [ABSTRACT FROM AUTHOR]

The efficacy of pollination biology of Mesogyne insignis is poorly known in fragmented forests of Amani Nature Reserve. This study was conducted to determine the effect of forest fragmentation on potential pollinators of this endangered species. Three intact forests and three forest fragments were selected for this study, the intact forests serving as control. Visual observation of insects visiting inflorescences, insect trapping and pollinator exclusion experiments were the methods employed in assessing pollination. Most members of the solitary bee genus Megachile were found to be potential pollinators of M. insignis. Diversity of pollinators was significantly higher in intact forests than in forest fragments. Overall, the total number of fruits set was significantly higher in intact forests than in forest fragments, perhaps a reflection of the higher diversity and abundance of potential pollinators in an intact forest. The pollination system of M. insignis is generalist in terms of systematic group of pollinators, and forest fragmentation may have significant impact on this pollination pattern. A similar study should be conducted in other Eastern Arc Mountains where M. insignis grows to find out whether the potential pollinators are similar or not. [ABSTRACT FROM AUTHOR]