© 1995 Heron Publishing—Victoria, Canada
Acid phosphatase activity and phosphorus nutrition in Scots pine needles
Kimmo K. Kolari (1) and Tytti Sarjala (2)
1. Finnish Forest Research Institute, Library/Information Services, P.O. Box 18, FIN-01301 Vantaa, Finland / 2. Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano, Finland / Received September 7, 1994
Summary
From March to October, acid phosphatase activity and phosphorus (P) concentration were measured in four needle age classes
of the upper and lower crowns of fertilized and unfertilized Scots pine (Pinus sylvestris L.) trees. Negative correlations between acid phosphatase activity and P concentration were observed in current-year needles
and in needles in the upper part of the crown, whereas there was a positive correlation between enzyme activity and P concentration
in older needles and in needles in the lower part of the crown. In May and October, needles of all ages showed increased acid
phosphatase activity. The most sensitive response of acid phosphatase activity to phosphate supply and phosphorus status of
the whole tree was seen in current-year needles on the first whorl where a 300% increase in acid phosphatase activity was
observed in response to a decrease in foliar P concentration of 1.7–1.8 mg P gDW–1.
Keywords:
phosphorus deficiency, Pinus sylvestris.
