Browsing by Author "Taplin, James"

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    Back To Africa: Post Hydropower-Project Mitigation Effects on Wetland Vegetation in Relation To The Conservation of an Endemic Amphibian
    (Wiley, 2012-07) Maren, Inger E.; Vandvik, Vigdis; Ndangalasi, Henry J.; Taplin, James; Mbago, Frank; Lovett, Jon C.
    Developing countries are home to much of the world’s biodiversity due to their location in areas of high species richness and their native vegetation has not yet been totally transformed by human activity. Enabling economic and social development to proceed whilst retaining the high environmental values is central to the principle of sustainability, but activities under these three pillars of sustainability are often in conflict. Provision of energy from environmentally sound technologies is critical for economic development in Africa and hydropower offers a reliable way of doing this. The Lower Kihansi Hydropower Project in Tanzania is a model example of the application of technology to minimise environmental impact. However, although the footprint of the project is relatively small, it is located in a biodiversity hotspot where almost any development will have negative impacts on its many restricted range species. Globally, hydropower projects have been associated with negative biological impacts of flooding of the reservoir impounded by the dam. Less attention has been paid to the immediate downstream effects of dams, such as the loss of waterfall spray zones. We analysed the effects of the mitigation efforts by the installment of a sprinkler system to prevent extinction of the Kihansi Spray Toad Nectophrynoides asperginis, which is only known from this short section of the Kihansi River. We analysed re-sampled vegetation plots in the spray wetland habitat over a period of eight years to test if the post-hydropower project mitigation has aided the vegetation composition in approaching similarity to that of the pre-hydropower project conditions, testing two hypotheses dealing with habitat responses to the mitigation measures; (i) Does the instalment of the sprinkler system alter plant species composition in the former waterfall spray zone in relation to the controls? (ii) Do the mitigation measures succeed in restoring the wetland habitat and hence facilitate the re-introduction of the Kihansi Spray Toad? The results clearly show that the post-hydropower mitigations are successful as the vegetation cover and species composition with time approach that of the pre-hydropower project conditions. Overall, the proportion of weedy species decreased and wetland species increased with time since mitigation. However, results suggest that the wetland has not entirely reverted back to pre-project conditions and continued mitigation measures are needed. In conclusion, this positive trend in the wetland habitat development due to the mitigation measures may facilitate the reintroduction of the in situ extinct Kihansi Spray Toad in the near future.
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    Increasing Carbon Storage in Intact African Tropical Forests
    (2009-03) Lewis, Simon L.; Gonzalez, Gabriela L.; Sonke, Bonaventure; Baffoe, Kofi A.; Baker, Timothy R.; Ojo, Lucas O.; Phillips, Oliver L.; Reitsma, Jan M.; White, Lee; Comiskey, James A.; Djuikouo, Marie N. K.; Ewango, Corneille E. N.; Feldpausch, Ted R.; Hamilton, Alan C.; Gloor, Manuel; Hart, Terese; Hladik, Annette; Lloyd, Jon; Lovett, Jon C.; Makana, Jean R.; Malhi, Yadvinder; Mbago, Frank M.; Ndangalasi, Henry J.; Peacock, Julie; Peh, Kelvin S. H.; Sheil, Douglas; Sunderland, Terry; Swaine, Michael D.; Taplin, James; Taylor, David; Thomas, Sean C.; Votere, Raymond; Woll, Hannsjorg
    The response of terrestrial vegetation to a globally changing environment is central to predictions of future levels of atmospheric carbon dioxide. The role of tropical forests is critical because they are carbon-dense and highly productive. Inventory plots across Amazonia show that old-growth forests have increased in carbon storage over recent decades, but the response of one-third of the world's tropical forests in Africa is largely unknown owing to an absence of spatially extensive observation networks. 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(-1) yr(-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(-1) (CI, 0.15-0.43). These reported changes in carbon storage are similar to those reported for Amazonian forests per unit area, 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 together yields a comparable figure of 0.49 Mg C ha(-1) yr(-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(-1) (CI, 0.8-1.6) across all tropical forests during recent decades. Taxon-specific analyses of African inventory and other data suggest that widespread changes in resource availability, such as increasing atmospheric carbon dioxide concentrations, may be the cause of the increase in carbon stocks, as some theory and models predict.