According to WWF - The Economic Value of Non-Wood Forest Products in Southeats Asia1989: "Non-wood products cover all other biological wood materials, exploited from natural forestsfor purposes of human, including foods, medicinal herbs, flavorings, essential oils, sap, glue, latex,tannin, dyes, ornamental plants, wild animals, raw materials and firewood, rattan and bamboo,small wood and yarn".
Recently, JHDe Beer (1996) authored many documents of non-timber forest products,including the "Analysis of Vietnam's Non-Timber Forest Products" in July 2000 as a publicationof the project "Sustainable Use Non-timber forest products” are defined as follows: Non-timberforest products include materials of biological origin, not from wood, exploited from forest to servepeople. These include food, medicine, spices, essential oils, plastics, latex, canines, dyes,ornamental plants, wild animals (live animals or their products), firewood and raw materials likebamboo, rattan, small wood and fiber.
....................
2.2 Review of international and domestic researches
2.2.1 Global studies
(1) Research on non-timber forest products
Foreign research and exploration in the field of NTFPs started earlier. Before the 1990s,foreign scholars focused on the social and economic benefits of NTFPs; after the 1990s, foreignscholars began to pay attention to the ecological benefits while paying attention to the social andeconomic benefits of NTFPs. This is because at the end of last century, there was a seriousecological crisis in the world. Many scholars began to focus on the ecological benefits of non-timber forest products. Foreign scholars mainly focus on the connotation and classificationecological and socio-economic benefits, development and utilization of existing problems ofNTFPs.
(2) Study on the connotation and classification of non-timber forest products
Many countries call of NTFPs, such as non-timber forest products, forest by-products, multiuse forest products, special forest products, forest by-products, etc. The term "non-timber forestproducts" has been adopted in FAO and international forestry research for many years has beenaccepted by most countries and organizations in the world. At the "Expert consultation on non-timber forest products " (1991) held in Bangkok, Thailand, it was defined as: all renewable products(excluding wood, fuelwood, charcoal, stone, water and tourism resources) w produced in the forestor on the ground for any similar purpose. In the research of FAO and Guojing forestry (19%), nontimber forest products are defined as various products for commercial, industrial and householduse obtained from forest and its biomass. Because there are many kinds of non-timber forestproducts, the standard of garden division in the world is not the same. The UN Food and AgricultureOrganization (1996) classifies non timber forest products into two types, which are suitable forhome use and suitable for market access. The former refers to forest food, health care products,perfume cosmetics, wild animal protein and woody edible oil, etc. the latter refers to Taketo'sknitting products, edible fungus products, insect products, forest natural spices and other. Due tothe clear definition and classification of non timber forest products, few foreign scholars havestudied this problem since w in 1996. In the 2005 global forest resources assessment report (2006)issued by the FAO, the name of no
