Agriculture is the main driver of deforestation in Tanzania

Reducing deforestation can generate multiple economic, social and ecological benefits by safeguarding the climate and other ecosystem services provided by forests. Understanding the relative contribution of different drivers of deforestation is needed to guide policies seeking to maintain natural forest cover. We assessed 119 randomly selected plots from areas deforested between 2010 and 2017, in Tanzania. Through ground surveys and stakeholder interviews we assessed the proximate deforestation drivers at each point. Crop cultivation was the most commonly observed driver occurring in 89% of plots, compared to livestock grazing (69%) and charcoal (35%). There was evidence of fire in 77% of plots. Most deforestation events involved multiple drivers, with 83% of plots showing signs of two or more drivers. Stakeholder interviews identified agriculture as the primary deforestation driver in 81% of plots, substantially more than charcoal production (12%), timber harvesting (1%) and livestock (1%). Policy-makers in Tanzania have sought to reduce deforestation by reducing demand for charcoal. However, our work demonstrates that agriculture, not charcoal, is the main driver of deforestation in Tanzania. Beyond protected areas, there is no clear policy limiting the conversion of forests to agricultural land. Reducing deforestation in Tanzania requires greater inter-sectoral coordination between the agriculture, livestock, land, energy and forest sectors

Targeted vertebrate surveys enhance the faunal importance and improve explanatory models within the Eastern Arc Mountains of Kenya and Tanzania

Detailed knowledge of species distributions, endemism patterns and threats is critical to site prioritization and conservation planning. However, data from biodiversity inventories are still limited, especially for tropical forests, and even well recognized hotspots remain understudied. We provide an example of how updated knowledge on species occurrence from strategically directed biodiversity surveys can change knowledge on perceived biodiversity importance, and facilitate understanding diversity patterns and the delivery of conservation recommendations.Francesco Rovero, Michele Menegon, Jon Fjeldså, Leah Collett, Nike Doggart, Charles Leonard, Guy Norton, Nisha Owen, Andrew Perkin, Daniel Spitale, Antje Ahrends and Neil D. Burges

Detecting and predicting forest degradation: A comparison of ground surveys and remote sensing in Tanzanian forests

Summary • Tropical forest degradation is widely recognised as a driver of biodiversity loss and a major source of carbon emissions. However, in contrast to deforestation, the more gradual changes from degradation are challenging to detect, quantify, and monitor. Here we present a field protocol for rapid, area-standardised quantifications of forest condition, which can also be done by non-specialists. Using the example of threatened high-biodiversity forests in Tanzania, we analyse and predict degradation based on this method. We also compare the field data to optical and radar remote sensing datasets, thereby conducting a large-scale, independent test of the ability of these products to map degradation in East Africa from space. • Our field data consist of 551 ‘degradation’ transects collected between 1996 and 2010, covering >600 ha across 86 forests in the Eastern Arc Mountains and coastal forests. • Degradation was widespread, with over one third of the study forests – mostly protected areas – having more than 10% of their trees cut. Commonly-used optical remote-sensing maps of complete tree cover loss only detected severe impacts (≥25% of trees cut), i.e. a focus on remotely sensed deforestation would have significantly underestimated carbon emissions and declines in forest quality. Radar-based maps detected even low impacts (<5% of trees cut) in ~90% of cases. The field data additionally allowed to differentiate different types and drivers of harvesting, with spatial patterns suggesting that logging and charcoal production were mainly driven by demand from major cities. • Rapid degradation surveys and radar remote sensing can provide an early warning and guide appropriate conservation and policy responses. This is particularly important in areas where forest degradation is more widespread than deforestation, such as in east and southern Africa

Optimisation of the material properties of indium tin oxide layers for use in organic photovoltaics

The influence of indium tin oxide [(In2O3:Sn), ITO] material properties on the output performance of organic photovoltaic (OPV) devices has been modelled and investigated. In particular, the effect of altering carrier concentration (n), thickness (t), and mobility (μe) in ITO films and their impact on the optical performance, parasitic resistances and overall efficiency in OPVs was studied. This enables optimal values of these parameters to be calculated for solar cells made with P3HT:PC61BM and PCPDTBT:PC71BM active layers. The optimal values of n, t and μe are not constant between different OPV active layers and depend on the absorption spectrum of the underlying active layer material system. Consequently, design rules for these optimal values as a function of donor bandgap in bulk-heterojunction active layers have been formulated

Biodiversity surveys in the East Usambara Mountains: Preliminary findings and management implications

Geographically referenced biodiversity information is important for conservation management and zoning. Biodiversity surveys were initiated in the East Usambara Mountains in 1995 to provide baseline information on the biological values of the forests for management planning and monitoring, and to train field staff in the use of biological inventory techniques. They were conducted in ten-week field phases. Vegetation plots were laid along a grid of 450 m x 450/900 m. Forest disturbance was assessed using the grid transects. Selected groups of fauna were surveyed using standard methods. Inventories have been completed in ten forests covering 11,076 ha. New species have been discovered, and several range extensions have been documented. Data on local distribution of endemics and threatened species has been incorporated in management plans for Forest Reserves. About 35 foresters have been trained. During 1997 a database was developed for data entry, retrieval and mapping.Journal of East African Natural History Vol. 87 (1&2) 1998: pp. 139-15

Agricultural fallows are the main driver of natural forest regeneration in Tanzania

Rates and drivers of natural forest regeneration are areas of uncertainty for policy, forest management and climate change mitigation. In this study, the rate of deforestation and the rate and drivers of natural regeneration are described for 56 million hectares of village land in Tanzania, a country undergoing rapid deforestation. To determine the regeneration and deforestation rates, remote sensing (RS) data for 500 randomly selected points were reviewed for a 34 year period from 1987 to 2021 using Google Earth Engine. Over this period, regeneration, involving a transition from forest to non-forest and back to forest was detected on 4.8% of village land (95% CI: 3.1%–7.1%), while 0.8% of land transitioned from non-forest to forest (95% CI: 0.2%–2.04%). 22% of village land was deforested (95% CI: 18.6%–26.1%), equivalent to a mean annual net loss of 0.35 million hectares of forest. Using a combination of RS data, field plots and structured interviews, the land cover change trajectories of 180 regenerating plots, in 10 sampling clusters, were assessed to identify regeneration drivers and assess biomass and tree species accumulation rates. Agricultural fallows are the regeneration driver in 47% of plots (95% CI: 39.8%–54.8%). Other common regeneration drivers include abandonment of cultivated areas for reasons apart from fallowing, conservation and post wood-extraction abandonment in 19% (95% CI: 13.9%–26%), 18.3% (95% CI: 13%–24.8%) and 12.8% (95% CI: 8.3%–18.6%) of plots, respectively. The mean carbon sequestration rate was 1.4 Mg C ha−1 y−1, equivalent to 4.3 Tg C y−1 (95% CI: 3.9–4.7 Tg C y−1) across the 3.15 million hectares of regenerating village land forest. The mean species accumulation rate was 1.08 species y−1 (95% CI: 1.0–1.2). Regeneration time, location and precipitation have the greatest influence on biomass and species richness. The study highlights the potential for natural regeneration to contribute to global and national climate and biodiversity goals and to sustainable, productive forest management. The importance of cooperation and policy-alignment between the forest, agriculture and land sectors are under-scored

Diverse Options Exist for Securing Sustainable Feedstock for Charcoal in the Global South

Charcoal is the primary energy used for cooking and heating in millions of homes and restaurants in the Global South. In Africa alone, which produces 65% of global production, an estimated 195million people are engaged in the production of firewood and charcoal. Despite decades of efforts to transition away from charcoal, consumption is growing and expected to increase in the foreseeable future as it continues to be the most affordable, accessible and preferred cooking fuel. Where wood supplies are diminishing, growing demand for charcoal threatens forests and forest-dependent livelihoods; it also frustrates efforts to reduce greenhouse gas emissions and curb biodiversity loss. Securing biomass that is renewable, reliable, economically viable and culturally acceptable is urgently needed in the Global South to develop sustainable charcoal sectors. In this policy brief, we present three tested approaches for producing feedstock for charcoal that can be applied to diverse contexts

Manga Forest reserve A biodiversity survey

East Usambara Conservation Area Management Programme ; produced in consultation with Univ. Dar es Salaam and othersAvailable from British Library Document Supply Centre-DSC:8692.065(41) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

The influence of energy policy on charcoal consumption in urban households in Tanzania

The sustainability of energy use in the residential sector has relevance for global initiatives to achieve sustainable development and limit climate change. Using the city of Dar es Salaam, in Tanzania, as a case study, we look at how national energy policy has influenced household cooking energy use between 1990 and 2018, and how energy policy could achieve further progress to realise national and global priorities. The study involved questionnaire surveys of households, retailers, transporters and producers of charcoal; semi-structured interviews with government officials and non-charcoal fuel suppliers; price data collection; a comparative analysis of prices and taxes for different cooking fuels; and policy and document review. Trends in energy policy and demand for different fuels, are compared. We find that Tanzania's national energy policies have focused on achieving an energy transition from biomass to electricity and fossil fuels, with an increasing focus on supply-side issues. Fiscal policy tools have been used effectively to reduce demand for kerosene, while increasing demand for liquefied petroleum gas. However, this has not resulted in a transition away from biomass, with most households using multiple fuels (fuel stacking). Charcoal remains the cheapest (excluding firewood) and most widely used fuel, reflecting the strong influence of price in consumer fuel choices. Energy policy needs to acknowledge the continued dominance of charcoal in urban energy use. In the context of rapid urbanisation and increased energy demand, there is a need for sustainable urban energy planning across a range of fuel types including charcoal, in ways that balance economic, social and environmental outcomes. Greater inter-sectoral coordination is needed to improve the sustainability of urban residential energy supplies