Does Raking Basal Duff Affect Tree Growth Rates or Mortality

Mortality and reduced growth rates due to raking accumulated basal duff were evaluated for old, large-diameter ponderosa and Jeffrey pine trees on the Lassen National Forest, California. No fire treatments were included to isolate the effect of raking from fire. Trees were monitored annually for 5 years after the raking treatment for mortality and then cored to measure basal area increment. Results showed that raking basal duff and litter to mineral soil from the bole out to 60 cm had no effect on basal area increment or mortality for 5 years posttreatment. Results are pertinent to managers who question whether raking basal duff will decrease tree vigor or increase tree mortality of large and old ponderosa and Jeffrey pine trees in northern California.