Search

Copyright of Journal of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Mangrove forests have gained recognition for their potential role in climate change mitigation due to carbon sequestration in live trees, and carbon storage in the sediments trapped by mangrove tree roots and pneumatophores. Africa hosts about 19% of the world's mangroves, yet relatively few studies have examined the carbon stocks of African mangroves. The available studies report considerable differences among sites and amongst the different pools of carbon stocks. None considered the effects of seaward distance. We present details of AGC and SOC carbon stocks for Lindi in Tanzania, and focus on how these values differ with increasing seaward distance and, how our results compare to those reported elsewhere across Africa. Results: AGC ranged between 11 and 55 Mg C ha−1, but was not significantly affected by seaward distance. SOC for 0–1 m depth ranged from 154 to 484, with a mean of 302 Mg C ha−1. SOC was significantly negatively correlated with seaward distance. Mangrove type (estuarine/oceanic), soil erosion, soil depth may explain these differences We note important methodological differences in previous studies on carbon stocks in mangroves in Africa. Conclusion: This study indicates that seaward distance has an important effect on SOC stocks in the Lindi region of Tanzania. SOC should be fully incorporated into national climate change mitigation policies. Studies should report seaward distance and to describe the type of mangrove stand to make results easily comparable across sites and to assess the true value of Blue Carbon in Africa. We recommend focusing on trees > 10 cm diameter for AGC, and sampling soils to at least 1 m depth for SOC, which would provide a more complete assessment of the potentially considerable mangrove carbon store. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the distribution of corneal spherical aberration (SA) in Tanzanian people of African descent, and to examine the correlation between corneal SA and ocular parameters. Design: Cross-sectional population-based study. Methods: Residents aged 40 years and older in three villages in the Mkuranga district in Tanzania were enlisted as study participants. Corneal higher-order aberrations (HOAs) for the right eye were measured with a wavefront analyzer (KR-1W, Topcon) and calculated for the central 6.0-mm zone. Corneal curvature radius (CR), corneal astigmatism, and axial length (AL) were also measured and their correlation with corneal SA was assessed. Results: The right eyes of 657 participants (336 male, 321 female) were analyzed. The mean age of the subjects was 57.2 ± 10.3 years (mean ± SD). The mean corneal SA (Zernike spherical aberration coefficient C40) was 0.188 ± 0.095 μm (-0.242 to 0.613). The SAs in about three-quarters of all subjects were between 0.10 and 0.30 μm. The root mean squares of total corneal HOAs and the third- and fourth-order aberrations were 0.629 ± 0.250 μm, 0.539 ± 0.236 μm, and 0.269 ± 0.110 μm, respectively. Corneal SA showed weak significant correlations with CR (Spearman’s rank correlation coefficient, r = -0.177, p < 0.001), corneal astigmatism (r = -0.142, p < 0.001), AL (r = -0.168, p < 0.001), and age (r = -0.085, p < 0.05). Conclusions: This finding may be beneficial for selecting aspheric intraocular lens in this population. [ABSTRACT FROM AUTHOR]

Abstract: Wetlands are crucial ecosystems with multiple values and functions to a range of different stakeholders. The future of wetlands depends both on the legacy of the past and how they are currently used. Using 48 vegetation survey plots (0.08 ha) combined with Landsat 5 and 7 TM imagery, we assessed the influence of long‐term (1990–2011) land use and land cover change on the biodiversity of the Kibasira Swamp. Information on perceptions of adjacent communities on historical changes and drivers for the changes were also collected. Results showed an increase in the area covered by open water by 1% and forest by 4% between 1990 and 1998 whilst Cyperus papyrus L and cultivated land area decreased by 8% and 3%, respectively on the same period. Between 1998 and 2011, there was a decrease in areas covered by water by 35% and forest by 9% whereas C. papyrus L increased by 40% and cultivated land increased by 8%. These changes have affected the biodiversity of the swamp and adjacent to it as numbers of mammals have declined. However, the Swamp still provides extensive habitat for plants and bird species despite the ongoing human pressure. Interventions may be necessary to maintain biodiversity in Kibasira Swamp to ensure sustainable ecosystem services. [ABSTRACT FROM AUTHOR]

Mining is important for economic development in many tropical countries, but mining can have serious impacts on biodiversity, both directly through operations at extraction sites, and indirectly via wider social-economic development. However, mitigation efforts by large-scale mining operators focus almost exclusively on extraction sites. We provide a rare assessment of mining impacts on vegetation structure and biodiversity with increasing distance from three commercial gold mines of varying ages in Tanzania (0 years, 8 years, and 19 years since establishment). We show that mining is associated with impacts that manifest largely outside operational lease boundaries. At the two older mine sites, aboveground carbon and tree stem density are significantly higher within lease boundaries compared to outside, while there is no such effect at the new site. Further, tree stem density, aboveground carbon, and tree and butterfly species richness all decrease with increasing distance from extraction sites, with these effects again increasing with mine age. Frugivorous bird species richness is lower outside older mines, while abundance declines in frugivorous and granivorous birds are associated with declines in tree stem density, which may have implications for forest regeneration. These impacts result from new and expanding settlements around mining concessions between 2000 and 2019 and associated demand for timber and fuelwood. We recommend rigorous, integrated impact assessments and conservation planning in mining landscapes, to pre-empt the development of settlements and secondary industries around mining sites and so balance outcomes across the mining sector, natural resource-based and other livelihoods, and conservation agendas. • Commercial gold mining impacts on adjacent ecosystems accumulate with age and distance from the mine. • Ecosystems adjacent to mines have reduced carbon stocks and altered tree, butterfly, and bird species communities. • These impacts of mining accrue indirectly via in-migration and socio-economic development. • Integrated land use planning can improve sustainable development in mining regions. [ABSTRACT FROM AUTHOR]

Highlights: [•] We present an accurate description of the Norwegian funded REDD project managed by WWF in Tanzania. [•] We refute the inaccuries in the paper published by Beymer-Farris and Bassett. [•] We discuss REDD implementation in Tanzania in relation to community forestry. [ABSTRACT FROM AUTHOR]