Even- vs. Uneven-aged Reproduction Methods

photo by Chris Demers

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