How does competition affect growth and yield?

• A. Competition from undesirable vegetation and individual trees can limit growth and yield.
• B. Competition increases growth rates.
• C. Competition has no effect on growth or yield.
• D. Competition only affects mortality but not growth.

Answer: (A)

Competition for light, water, and nutrients is the main factor that slows growth and reduces yield in forests. When undesirable vegetation and neighboring trees compete for these resources, each tree has less access, so height and diameter growth slow and the stand’s total volume potential drops. This effect is seen in dense or weed-infested stands where light is scarce and trees invest less in bole growth, resulting in smaller trees and lower eventual yield. Competition does not boost growth, does not have no effect, and does not affect only mortality; it directly suppresses growth and final yield. So the statement that competition can limit growth and yield is the best description.