The material a forest can yield annually (or periodically) in perpetuity
- The regular continuous supply of desired produce to the full capacity of the forest
- The concept of sustained yield was brought to U.S, from Europe at the beginning of 19thcentury
The concept of Sustained Yield
- Ensures stability and continuous supply of raw materials to the industries and to meet social and domestic needs of the people.
- The basic consideration is that the later generations may derive from the forest at least as much of the benefits as the present generation.
- Forest should be exploited such that annual or periodic felling do not exceed annual or periodic growth.
Sustained Yield Management
Continuity of harvest, indefinitely, without impairment of productivity of soil.
Pre-requisites for Sustained Yield Management
To maintain a complete succession of equal areas of crops of all ages from one year to age of maturity.For higher rotations, age classes may be formed [1-10, 10-20, 20-30, 30-40 Age class]
Limitations
- Not possible to apply sustained yield principle in the first rotation (-Density and quality of crop varydue to past management and also the composition of main spp. In mixture)
- Virgin forests with a large proportion of deteriorating trees cannot be suitably worked under sustained yield principle.
- Forests under afforestation programmed provide various yields until after the end of first rotation.
- Lack of technical manpower
- Inflexible to market conditions
Management steps for Sustained Yield
To bring forest to clear-felling system in which all age-gradations from one year to rotation are present.For natural regeneration, ten or even more age-gradations may be grouped (0-10, 10-20, 20-30,……..,to form age-class and the oldest age-class felled and regenerated to ten yearsIn selection forest, trees felled for exploitable size diameter
Source: Sustained yield concept in forest management-B.K. Paudyal. 1986. Forestry (9): 3-8
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