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A free email agroforestry journal for practitioners, extension agents, researchers, professionals, students, and enthusiasts. One edition is sent each month focusing on a concept related to designing, developing, and learning more about trees and agroforestry systems. Focuses on trees and their roles in agriculture, natural ecosystems, human culture and economy.

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Overstory #203 - Connecting small forest enterprises


Forest enterprise has been extensively examined as a means of alleviating the widespread poverty among forest-dependent people. When poverty alleviation is considered solely in terms of income generation, small forest enterprises may or may not compare favourably with larger enterprises. However, when broader dimensions of well-being are considered, small forest enterprises are seen to have a vital role in enhancing the quality of life of forest-dependent people and lifting them out of poverty. Beyond basic health and subsistence, these broader dimensions of human value include security and freedom from oppression; decent, creative and fulfilling work; social relationships and networks; appreciation and management of a beautiful environment; and identity, faith and culture. A large body of international law supports these values by according them the status of legal rights (Macqueen, 2007) – for example, the rights to life, liberty and physical integrity of the person, to food, to justice or to a clean environment.

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Overstory #202 - Direct Marketing of Agroforestry Products


Agroforestry can enhance cash flow on many farms through the production of high-value forest products. The greatest challenge, however, is often marketing rather than production. Unlike commodity crops that have a readily available, but relatively uncompromising, market; the market for some agroforestry products is not always apparent. Landowners may need to take an active role in marketing to reap the benefits of their production. Producer goals, resources, and products, as well as local customer needs and habits usually dictate marketing strategies. This Note describes several different direct marketing strategies that might be used to market agroforestry products. Many variations on these options exist--the only limitation is one's creativity.

Direct marketing is based on selling a product directly to the consumer. It involves the elimination of one or more middle steps in the marketing process. As a result, the producer receives a significant percentage of the retail price. At the same time, responsibility for selling farm products is shifted from the retailer to the producer, making direct marketing more risky but potentially more rewarding than wholesale marketing.

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Overstory #201 - Indigenous Fruit Tree Domestication

Editor's note

This excerpt of a newly released CABI publication frequently cites chapters in the original publication (see "Original Source" below). Please refer to the original publication for further reference.

Why domesticate indigenous fruit and nut trees (IFTs)?

Out of the 250,000 higher plant species in the world, less than 1% have been domesticated as food plants and, of these, about 50% are fruit trees that are either domesticated or semi-domesticated (Leakey and Tomich, 1999). In Tanzania, about 326 indigenous plants have been described as edible (Ruffo et al., 2002) but few, if any, of these species have been domesticated through deliberate tree improvement programmes (Akinnifesi et al., 2006a). An inventory of fruit trees in Nigeria and Cameroon showed that 56% of fruit trees are indigenous (Schreckenberg et al., 2006), and many of them are endemic to some locations (A. Degrande et al., unpublished). Farmers listed more than 200 species in Latin America that they would like to cultivate (Weber et al., 2001).

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Overstory #200 - The art of farm silviculture


Silviculture (from the Latin "silva" meaning wood) is simply the manipulation of forests, and the trees within them, for wood production. The potential to direct tree and forest growth to enhance value makes silviculture the most powerful tool of the farm forester whatever their interests. For example, a tree that might otherwise only be of value for firewood can be turned into high value veneer or saw1og, or, a regrowth native forest dominated by one tree species can be thinned to promote greater biodiversity in the understorey.

A "silvicultural regime" is a series of management interventions that are imposed on trees, or forests, over time, from establishment through to harvest. The tools used include the choice of initial spacing, layout and establishment method and the type and timing of thinning, pruning, fire, grazing, harvesting or other interventions. Choosing to "let nature take its course" is, in a way, a silvicu1tura1 decision. Unfortunately, leaving a forest to its own devices is rarely the most appropriate means of providing the mix of economic products and environmental services farmers commonly seek. This article reviews how trees grow and highlights some of the more universal principles of silviculture that farmers can use to redirect forest growth in order to satisfy their own goals.

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Overstory #199 - Benefits from organic agriculture in and around protected areas

Ecological principles behind organic agriculture

The Convention on Biological Diversity "encourages the development of technologies and farming practices that not only increase productivity, but also arrest degradation as well as reclaim, rehabilitate, restore and enhance biological diversity and monitor adverse effects on sustainable agricultural diversity. These could include, inter alia, organic farming, integrated pest management, biological control, no-till agriculture, multi-cropping, intercropping, crop rotation and agricultural forestry" (Decision III/11, 15 e).

While several agricultural approaches make sustainability claims, organic agriculture is the only well-defined agricultural management system, including recommended and restricted practices that aim at environmental protection and food production. The decades-long implementation of organic agriculture, including inspection and certification to ensure compliance, as well as the steady growth of organic food sales on the global market, offer a living example of a viable system that reconciles conservation and production needs.

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Overstory #198 - Windbreak Density: Rules Of Thumb For Design


Information on appropriate windbreak density for specific purposes is readily available. For example, living snowfences, crop protection, and snow distribution designs each have different density recommendations. However, information on selecting species and spacing to achieve a specific windbreak density is more difficult to find. Measuring or estimating windbreak density is another problem altogether. This Agroforestry Note provides some basic designs, including example tree species and spacing along with pictures of real windbreaks that represent the three primary ranges of density for which windbreaks are designed.

Optical density

Windbreak density is a complex subject. From an aerodynamic point of view, the three dimensional arrangement of leaves, twigs, branches, and trunks determines how the air moves through the trees and the cumulative effect they have on wind speed. From a field practitioner's point of view, it is not yet possible to design or assess the three dimensional windbreak density, but optical density can be estimated in the field. Throughout this Agroforestry Note the density referred to is the optical density of a windbreak. That is, when looking at the broad face of a windbreak, the proportion of the view that is filled with leaves, branches and trunk is the optical density. The portion of the view that is made up of background and sky that can be seen through the windbreak is the optical porosity. Designing a windbreak with 100 percent optical density is easily done, however greater than 80 percent three dimensional density is not achievable.

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