The effects of seaward distance on above and below ground carbon stocks in estuarine mangrove ecosystems

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

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

Dynamics of Coffee Certifications in Producer Countries: Re-Examining the Tanzanian Status, Challenges and Impacts on Livelihoods and Environmental Conservation

Certification is increasingly becoming necessary for accessing coffee export markets and practicing environmental conservation, especially at this time when many of the farmers in developing countries strive to achieve agricultural transformation. Using data from 400 randomly selected coffee farmers in Tanzania, the study determined the status, constraints, key drivers, and impact of coffee certifications. Descriptive statistics and the endogenous switching regression (ESR) model were used for data analysis. Results indicated that the level of coffee certification is low, being constrained by unawareness and inaccessibility, the prevalence of coffee diseases, failure in realizing price advantages, and certification not being cost effective. Economies of scale, experience, and participation in collective actions are significant factors affecting coffee farmers’ decision to join certification schemes. Additionally, the study rejects the hypothesis of certification to improve household income. However, certification improved awareness and practices of environmental conservation among coffee farmers. It is thus important to embark on awareness creation and make certification services accessible and cost effective to coffee farmers for increased access to niche export markets. Easing transmission of price premiums to coffee farmers will also increase the supply of sustainably grown coffee, improve coffee farmers’ livelihood, and help in the attainment of environmental sustainability goals within the coffee supply chain

Woodlands degradation in the Southern Highlands, Miombo of Tanzania: implications on conservation and carbon stocks

Miombo woodlands is one of the major forest vegetation types covering about two thirds of the country forest land and form an integral part of the rural landscape in Tanzania, also they play crucial role in providing wide range of ecosystem services including carbon sequestration. This study aimed at assessing the effects of degradation on the structure and carbon stocks of miombo woodlands. Data were collected from 50 rectangular plots measuring 40×20 m. Stump diameter, diameter at breast height, tree height and species local and botanical names were recorded. Analysis was done by using R software and excel spread sheet. Results showed total harvesting of 10.53 m3ha-1 as compared to standing volume of 32.6 ± 2.3 m3ha-1 with basal area of 4.73 ± 0.5 m2ha-1. Estimated annual harvesting was found to be 6.63 ± 3.0 m3 ha-1 which exceeds mean miombo annual increment of 4.35 m3 ha-1 year1, this is indicator for unsustainable utilization which could results into woodland change. Harvesting resulted into total loss of 4.1±0.9 tCha-1 equivalent to 15.05 ± 3.3 tCO2eha,-1 new harvesting presenting 9.91 tCO2e ha-1 and old 5.14 tCO2eha-1. Managing the miombo woodlands carbon stocks for emissions and climate change mitigation in Tanzania and elsewhere requires rigorous effort to reduce anthropogenic degradation.This article is also available at http://www.academicjournals.org/IJBCCCIAM programme in Tanzania jointly implemented by Norwegian government and Tanzania government

Miombo of Tanzania: Implications on conservation and

carbon stock

Carbon storage, structure and composition of miombo woodlands in Tanzania’s Eastern Arc Mountains

African Journal of Ecology, 2011; 49: 332–342We determine the aboveground biomass and carbon stor- age (ABGC) of trees and the herbaceous layer in miombo woodland in the Eastern Arc Mountains (EAM) of Tanza- nia. In four 1-ha sample plots in Nyanganje and Kitonga Forests, we measured all trees ‡10 cm diameter alongside height and wood mass density. The plots contained an average of 20 tree species ha )1 (range 11–29) and 344 stems ha )1 (range 281–382) with Shannon diversity values of 1.05 and 1.25, respectively. We weighted nine previously published woody savannah allometric models based on whether: (i) the model was derived from the same geographical region; (ii) the model included tree height ⁄ - wood mass density in addition to stem diameter; and (iii) sample size was used to fit the model. The weighted mean ABGC storage from the nine models range from 13.5 ± 2 to 29.8 ± 5 Mg ha )1 . Measured ABGC storage in the herbaceous layer, using the wet combustion method, adds 0.55 ± 0.02 Mg C ha )1 . Estimates suggest that EAM miombo woodlands store a range of 13–30 Mg ha )1 of carbon. Although the estimates suggest that miombo woodlands store significant quantities of carbon, caution is required as this is the first estimate based on in situ data

Carbon storage, structure and composition of miombo woodlands in Tanzania’s Eastern Arc Mountains

African Journal of Ecology, 2011; 49: 332–342We determine the aboveground biomass and carbon stor- age (ABGC) of trees and the herbaceous layer in miombo woodland in the Eastern Arc Mountains (EAM) of Tanza- nia. In four 1-ha sample plots in Nyanganje and Kitonga Forests, we measured all trees ‡10 cm diameter alongside height and wood mass density. The plots contained an average of 20 tree species ha )1 (range 11–29) and 344 stems ha )1 (range 281–382) with Shannon diversity values of 1.05 and 1.25, respectively. We weighted nine previously published woody savannah allometric models based on whether: (i) the model was derived from the same geographical region; (ii) the model included tree height ⁄ - wood mass density in addition to stem diameter; and (iii) sample size was used to fit the model. The weighted mean ABGC storage from the nine models range from 13.5 ± 2 to 29.8 ± 5 Mg ha )1 . Measured ABGC storage in the herbaceous layer, using the wet combustion method, adds 0.55 ± 0.02 Mg C ha )1 . Estimates suggest that EAM miombo woodlands store a range of 13–30 Mg ha )1 of carbon. Although the estimates suggest that miombo woodlands store significant quantities of carbon, caution is required as this is the first estimate based on in situ data