Even- vs. Uneven-aged Reproduction Methods

Even- and uneven-aged reproduction methods have several advantages and disadvantages associated with them. When choosing a reproduction method it is first necessary to determine:
- what you seek
- what species and stand conditions will satisfy your objectives
- the type of stand you want, given the species sought or uses intended
- what physical or economic constraints you face in achieving the desired results
EVEN-AGED | UNEVEN-AGED | ||
---|---|---|---|
Advantages | Disadvantages | Advantages | Disadvantages |
Allows almost complete control over stand establishment | Supply of seed or seedlings must come from outside of the stand to be established, unless shelterwood or seed tree reproduction methods are employed | Seed supply comes from the residual stand, ease and certainty of natural regeneration with some species (especially loblolly) | Depending on species, control over stand establishment may be more difficult to achieve |
Less root competition in the regenerated stand | Higher potential for damaging erosion to occur | Lower potential for damaging erosion to occur | Dependign on size of cuts and species, may be more root competition in the residual stand |
Suitable for regenerating shade-intolerant tree species. | Shade-tolerant species may be overly exposed | Depending on size of cuts and species, may be suitable for regenerating shade-tolerant tree species | Depending on size of cuts and species, may not be suitable for regenerating shade-intolerant tree species |
Enables use of genetic improvements, if necessary, when planted | Usually less biologically diverse, particularly young stands | Usually more biologically diverse | May be difficult to use genetic improvements, if necessary |
Relatively simple to achieve a balanced, sustained yield of forest products | Modest income at thinnings, significant income only at final harvest | Growth capacity of site can be converted to revenue at short intervals | More challenging to to achieve a balanced, sustained yield of forest products |
Costly site preparation, including use of pesticides and heavy equipment, is usually necessary | Site preparation is usually unnecessary | ||
May be higher risk of disease, insect problems, and wildfire | Depending on density and other variables, may be lower risk of disease, insect problems, and wildfire |
- Return to Silviculture or to Uneven-aged Management