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.

Concise, informative • Subscribers in over 180 countries 
Easy to subscribe/unsubscribe

Overstory #153 - Online species references for agroforestry

Online species references

Although some of the best species references for agroforestry and forestry are still only found in book form, several very useful species databases have appeared online during the past few years. This is a list of some of the online species resources that are most useful. Feel free to send additional web site recommendations to us at: overstory@agroforestry.net.

Listings are arranged in no particular order.

Agroforestree (AFT) database by the World Agroforestry Centre (formerly the International Centre for Research in Agroforestry (ICRAF)) is a tree species reference and selection guide for agroforestry trees covering more than 500 species.

FACT Sheets (formerly NFT Highlights) by Winrock International, Morrilton, Arkansas, give concise summaries about many multipurpose tree and shrub species (many available in Spanish, French, Indonesian, Chinese, Vietnamese, and Khmer).

Forage Tree Legumes in Tropical Agriculture (Editors: R. Gutteridge and M. Shelton, 1994 [republished 1998]), published by The Tropical Grassland Society of Australia, St Lucia, Queensland, Australia (previously published by CAB International, Wallingford, UK) covers a number of multipurpose tree legumes that can serve as ruminant forage in silvopastoral agroforestry systems.

Continue Reading

Overstory #152 - Trees on farm to mitigate the effects of HIV/AIDS in SSA

Introduction: Agriculture and HIV/AIDS

The UNAIDS epidemic update reports that in 2004 alone, the global HIV/AIDS epidemic killed more than 3.1 million people, and that an estimated 4.9 million acquired the human immunodeficiency virus (HIV). This brings to 40 million the number of people living with the virus around the world (UNAIDS 2005). Sub-Saharan Africa (SSA) remains by far the worst affected: also in 2004, an estimated 25.4 million people in this region were living with HIV, this figure taking into account the 3.1 million people who became infected with HIV and the 2.3 million who died from AIDS. Even countries praised for their consistent efforts to fight HIV/AIDS, such as Uganda, which has shown consistent declines in HIV prevalence levels since the mid-1990s, continue to be burdened with a serious epidemic. HIV/AIDS has now become a permanent feature.

Continue Reading

Overstory #148 - Markets for farm forestry products and services

There are lots of products, but few markets

Primary school children learn from an early age of the wide range of products and services that trees and forests provide. The typical school poster shows a clean stream of water flowing out of a rich native forest that provides a habitat for native animals, clean air and healthy soils. People can be seen bushwalking or fishing and there are groups of school children learning about forest life. Beside the forest, there are rural communities and industries that draw on the forest for timber, honey and other products. There are also farms with animals sheltering from the wind and trees along waterways protecting the soil. Electricity lines from the hydro schemes and water pipes from the dams link the forests with the all-consuming cities.

All these products and services that forests provide are real and benefit individuals, private companies and communities. While conventional wood products continue to be traded in local and international markets, there is renewed interest in identifying alternative tree and forest products such as bush foods, oils and pharmaceuticals. In addition, government agencies and catchment boards are seriously considering, and even testing, market mechanisms for the purchase of conservation values from forest owners.

Continue Reading

Overstory #147 - Major Themes of Tropical Homegardens


Farming systems variously described in the English language as agroforestry homegardens, household or homestead farms, compound farms, backyard gardens, village forest gardens, dooryard gardens and house gardens abound in the tropics. Some local names such as Talun-Kebun and Pekarangan that are used for various types of homegarden systems of Java (Indonesia), Shamba and Chagga in East Africa, and Huertos Familiares of Central America, have also attained international popularity because of the excellent examples of the systems they represent (Nair 1993). Although several authors have tried to describe the term "homegarden," none is perhaps universally accepted as "the definition"; but it is well understood that the concept refers to "intimate, multi-story combinations of various trees and crops, sometimes in association with domestic animals, around homesteads."  These multistrata agroforests are estimated to occupy about 20% of the arable land in Java (Jensen 1993a) and are regarded as the "epitome of sustainability" throughout the tropics (Torquebiau 1992). Homegardening has been a way of life for centuries and is still critical to the local subsistence economy and food security in Kerala state in peninsular India that has about 5.4 million small gardens (mostly less than 0.5 ha in area) (KSLUB 1995). In Africa, Central America, and the Caribbean and the Pacific Islands also, homegardens are of vital importance (Anderson 1993; Caballero 1992; Clarke and Thaman 1993; High and Shackleton 2000; Rugalema et al. 1994a, 1994b, 1995; Ruthenberg 1980).

Continue Reading

Overstory #146 - Improving Edible Species of Forest Products


The contributions of wild fruits, nuts, seeds, vegetables and other classes of edible products to the local diet in developing countries and their potential in overcoming or ameliorating prevailing food problems are enormous (Getahun, 1974; Okafor, 1975a, 1980a, 1980b, 1981a; Okigbo, 1977; Roche, 1975a).

Edible forest products include edible nuts and seeds used as staple foods or main dishes; those used as minor food supplements; condiments, thickening agents and flavours; leafy vegetables; edible flowers; fresh fruits; fresh seeds; edible oil; spices; fruit drinks and nonalcoholic beverages; alcoholic drinks (plus flavouring barks); mushrooms; honey; and bush meat (game, snails, insects, etc.).

Forest plants are important and cheap sources of vitamins, minerals, protein, carbohydrates and fats; moreover, their dietary contribution is increased because they are available during most seasons, including strategic periods in the year when the conventional staples and vegetables are scarce. For example, the African pear (Dacryodes edulis) matures during the "hungry season" when staples such as yam, cocoyam and rice have been planted but are not yet ready for harvest. Similarly, flushes from trees such as Pterocarpus spp. and Vitex doniana, which are used as vegetables, are available during dry seasons when cultivated vegetables are scarce or obtainable only where there are irrigation facilities.

Continue Reading

Overstory #145 - Wild Foods and Food Security

Editor's note: Due to the extremely large number of references cited in this article (well over 200), the reader is referred to the original source for cited literature. The citation numbers in this excerpt text correspond to the numbers in the bibliography of the original source. See below under Original Source for the citation and information about where to purchase the book.


Food insecurity develops though several stages. These begin with 'coping,' which involves selling surplus animals and non-essential possessions, borrowing from close kin, collecting wild foods, etc. This stage can progress to 'asset disposal,' involving sale of animals, outmigration, pledging or sale of farmland, and so on. The last stage is 'non-coping' or starvation (or charity dependency) (380; 389; 422; 451). Wild foods may be important at all stages.

Contribution to food security

The use of wild foods as a component of local response to increasing food insecurity is widely documented (374; 375; 383; 400a; 413; 414; 416; 417; 440; 441). 'Famine foods' include wild vegetables, berries, nuts, fruits, insects, etc. In periods of limited food stress, such foods may be eaten only occasionally and more often by children and poorer sectors of society. However, in periods of heightened food insecurity such foods may become widely consumed (386b; 387; 390; 418). For instance, in Java outputs from home gardens increase in times of rice shortage (151a, b).

Continue Reading