Women and men in tropical dry forests: a preliminary review

From a broad review of 670 publications on gender and forests, ~130 were found to address the world’s dry forests. These were examined with the intent to extract gendered social, cultural, political and economic patterns of relevance in such forests. Seven interrelated themes recurred in this literature: 1) population pressure, 2) migration, 3) intra-familial and inter-group conflict, 4) hierarchy and significant power differences, 5) strict gender differentiation, 6) commercialization of crops and NTFPs, and 7) fuelwood collection. Based upon these themes, the uniqueness of each situation and the importance of finetuning any approach to local realities to generate outcomes that can benefit women, we propose four promising ways to enhance the prospects for gender equity in dry forest areas: 1) a strengthening of groups and collective action, 2) explicit challenges to traditional gender norms, 3) a focus on products and spaces that interest women, and 4) addressing migration and population issues

A simple field based method for rapid wood density estimation for selected tree species in Western Kenya

Wood density is an important variable for accurate quantification of woody biomass and carbon stocks. Conventional destructive methods for wood density estimation are resource intensive, prohibiting their use, limiting the application of approaches that would minimize uncertainties in tree biomass estimates. We tested an alternative method involving tree coring with a carpenter's auger to estimate wood density of seven tropical tree species in Western Kenya. We used conventional water immersion method to validate results from the auger core method. The mean densities (and 95% confidence intervals) ranged from 0.36 g cm−3 (0.25–0.47) to 0.67 g cm−3 (0.61–0.73) for the auger core method, and 0.46 g cm−3 (0.42–0.50) to 0.67 g cm−3 (0.61–0.73) for the water immersion method. The auger core and water immersion methods were not significantly different for four out of seven tree species namely; Acacia mearnsii, Mangifera indica, Eucalyptus grandis and Grevillea robusta. However, wood densities estimated from the auger core method were lower (t (61) = 7.992, P = <0.001). The ease of the auger core method application, as a non-destructive method in acquiring wood density data, is a worthy alternative in biomass and carbon stocks quantification. This method could protect trees outside forests found in most parts of Africa

The management of tree genetic resources and the livelihoods of rural communities in the tropics: non-timber forest products, smallholder agroforestry practices and tree commodity crops

Products and services provided by trees in forests and farmland support the needs and promote the wellbeing of hundreds of millions of people in the tropics. Value depends on managing both the diversity of tree species present in landscapes and the genetic variation within these species. The benefits from trees and their genetic resources are, however, often not well quantified because trade is frequently outside formal markets, there is a multiplicity of species and ways in which trees are used and managed, and genetic diversity within species is frequently not given proper consideration. We review here what is known about the value of trees to rural communities through considering three production categories: non-timber products harvested from trees in natural and managed forests and woodlands; the various products and services obtained from a wide range of trees planted and/or retained in smallholders’ agroforestry systems; and the commercial products harvested from cultivated tree commodity crops. Where possible, we focus on the role of intra-specific genetic variation in providing support to livelihoods, and for each of the three production categories we also consider wider conservation and sustainability issues, including the linkages between categories in terms of management. Challenges to ‘conventional wisdom’ on tree resource use, value and management – such as in the posited links between commercialisation, cultivation and conservation – are highlighted, and constraints and opportunities to maintain and enhance value are described

Innovative biomass cooking approaches for sub-Saharan Africa.

Eradicating poverty and achieving food and nutrition security in a sustainable environment is difficult to achieve without adequate access to affordable cooking fuel. It is therefore important to understand the common sources of cooking energy used by people in rural areas and the challenges faced in making fuel sources economically viable, socially acceptable and ecologically sustainable. In the sub-Saharan Africa (SSA) region, more than 90% of the population relies on firewood and charcoal (wood fuel, collectively) as a primary source of domestic energy. Wood fuel sustainability is challenged by unsustainable harvesting and inefficient methods of converting wood into energy. The use of inefficient cook stoves contributes to wood wastage and smoke exposure associated with severe illnesses. Households often abandon traditional nutritious diets that take a long time to cook, reduce the number of meals, and spend income on fuel at the expense of food costs. Innovations exist that have the potential to provide affordable and cleaner tree-based cooking fuel. Pruning trees on the farm as a fuel source brings firewood closer to women, lightens their workload, saves time and reduces income spent on cooking fuel. Using briquettes or gas cook stoves can reduce health risks associated with food preparation and reduce income spent on cooking fuel due to increased fuel efficiency. The development of these innovations indicates the need for a multi-disciplinary approach to increase awareness of the benefits of cooking fuel innovations, encourage further research on product quality enhancement and standardization, to understand cultural and behavioral issues influencing adoption, and integrate innovations into bioenergy policy frameworks

From Tree Planting to Tree Growing: Rethinking Ecosystem Restoration Through Tree

Every year, millions of dollars are spent on tree-based landscape restoration activities. Over the last five decades, there are few success stories of such interventions and even those do not match the anticipated objectives for which the resources were spent. News articles that announce planting campaigns of millions of seedlings are common. Despite all this, in many countries, vegetation cover has not improved due to poor seedling survival rate. This makes the return on investment low. The objective of this paper is to highlight the main underlying challenges that need to be tackled to make restoration through tree-based interventions successful. Numerous challenges hamper the success of project-supported public tree growing schemes. 1) Often tree planting is stated as the ultimate objective of the intervention; when that objective should instead be tree growing. Performance indicators are often the number of trees planted or area planted, not the number of trees grown, or the area of land covered with grown trees. 2) Most projects operate on a short time frame (1-3 years) while many tree species (e.g. native trees in many African countries) need more time to sufficiently grow. 3) Emphasis on the right trees, for the right place and the right purposes, is very weak. 4) Even in projects of adequate duration emphasis on after-planting management is often limited. 5) There is lack of tree tenure to formally transfer the management of planted trees to local communities who reside in the landscapes over a long period of time. Tackling these challenges and changing mindsets is crucial if restoration through tree-based interventions is to yield the intended outcomes of reversing ecosystem degradation

Understanding the roles of forests and tree-based systems in food provision

Forests and other tree-based systems such as agroforestry contribute to food and nutritional security in myriad ways. Directly, trees provide a variety of healthy foods including fruits, leafy vegetables, nuts, seeds and edible oils that can diversify diets and address seasonal food and nutritional gaps. Forests are also sources of a wider range of edible plants and fungi, as well as bushmeat, fish and insects. Treebased systems also support the provision of fodder for meat and dairy animals, of “green fertiliser” to support crop production and of woodfuel, crucial in many communities for cooking food. Indirectly, forests and tree-based systems are a source of income to support communities to purchase foods and they also provide environmental services that support crop production. There are, however, complexities in quantifying the relative benefits and costs of tree-based systems in food provision. These complexities mean that the roles of tree-based systems are often not well understood. A greater understanding focuses on systematic methods for characterising effects across different landscapes and on key indicators, such as dietary diversity measures. This chapter provides a number of case studies to highlight the relevance of forests and tree-based systems for food security and nutrition, and indicates where there is a need to further quantify the roles of these systems, allowing proper integration of their contribution into national and international developmental policies

tropiTree:an NGS-based EST-SSR resource for 24 tropical tree species

The development of genetic tools for non-model organisms has been hampered by cost, but advances in next-generation sequencing (NGS) have created new opportunities. In ecological research, this raises the prospect for developing molecular markers to simultaneously study important genetic processes such as gene flow in multiple non-model plant species within complex natural and anthropogenic landscapes. Here, we report the use of bar-coded multiplexed paired-end Illumina NGS for the de novo development of expressed sequence tag-derived simple sequence repeat (EST-SSR) markers at low cost for a range of 24 tree species. Each chosen tree species is important in complex tropical agroforestry systems where little is currently known about many genetic processes. An average of more than 5,000 EST-SSRs was identified for each of the 24 sequenced species, whereas prior to analysis 20 of the species had fewer than 100 nucleotide sequence citations. To make results available to potential users in a suitable format, we have developed an open-access, interactive online database, tropiTree (http://bioinf.hutton.ac.uk/tropiTree), which has a range of visualisation and search facilities, and which is a model for the efficient presentation and application of NGS data

Identification and characterisation of an extrachromosomal element from a multidrug-resistant isolate of trypanosoma brucei brucei.

Drug resistance together with difficulties involved in the development of new trypanocides are a major problem in the present control of African trypanosomiasis. DNA based diagnostics for drug resistance would overcome problems in the identification of drug-resistant populations and contribute to effective control measures. However, this requires a detailed knowledge of the mode of action and the mechanisms by which trypanosomes can overcome the toxic effects of trypanocides. In this study, a search for molecular differences between a multidrug-resistant isolate of Trypanosoma brucei brucei, CP 547, and a reference drug-sensitive population, ILTat 1.4, led to the identification of a 6.6 kbp extrachromosomal element in the multidrug-resistant population. In light of the involvement of extrachromosomal elements in drug resistance in Leishmana spp. and cancer cells, the identification of the 6.6 kbp element warranted its characterisation. Several different approaches sere attempted before a sequence which hybridised to the 6.6 kbp element its eventually isolated. This sequence is represented by a 108 bp repeat sequence which forms long arrays of tandem repeats. Since N/a III is the sole restriction enzyme that cuts within the repeat, it has been referred to as an N/a III repeal The repeat is flanked by a 5 bp spacer sequence. However, a unique 5 bp direct repeat flanking two complete, and one partial copy of the N/a III repeat may signify the transposition of these sequences. Hybridisation with the N/a III repeat revealed the presence of 'higher' hybridising elements which also appear to be predominantly composed of long tandem arrays of the N/a Ill repeal Through exploitation of the p01) merase chain reaction using arbitrary primers (AP-PCR), additional sequences were identified which are associated with some of the 6.6 kbp and 'higher' hybridising elements. The 6.6 kbp element and some of the 'higher' hybridising elements display features of circular DNA molecules. The 6.6 kbp element also displays some level of size and sequence heterogeneity within different populations of the same trypanosome isolate. The copy number of the 6.6 kbp element is also not stable and appears to be directly affected by the application of selective drug pressure, but a direct association between the presence of the element and the expression of multidrug resistance could not be determined. The N/a III repeat family represents a newly identified repetitive family specific to members of the Trypanozoon subgenus. This repeat family, representing about 5% of the parasite genome, is dispersed through all size classes of chromosomes, in addition to its presence on the extrachromosomal elements. Transcriptional studies of the N/a III repeats have revealed that their transcription is developmentally regulated, since heterogeneous transcripts ranging from greater than 10 kb to smaller than 300 bp are present in the actively dividing long slender bloodstream and insect stage procyclic forms of the parasite but not nondividing, stumpy bloodstream forms. Lastly, the N/a III repeat lacks an open reading frame and transcripts do not appear to have a spliced leader sequence at the 5' end. Furthermore, there is almost an equal representation of polyadenylatcd and non-polyadenlyated transcripts