The Internal Transfer of Nutrients in a Scots Pine Stand 2. The Patterns of Transfer and the Effects of Nitrogen Availability

Abstract

The fall of fine litter was 4.5 tonnes ha ⁻¹ y ⁻¹ , (78% needles) returning to the ground 36.6 kg N, 2.2 kg P, 7.6 kg K, 12.1 kg Ca and 2.0 kg Mg. Nutrient input in rainfall (880 mm in 1978) was 2.6 kg N, 0.4 kg P, 4.3 kg K, 7.6 kg Ca and 1.4 kg Mg. Throughfall was 534 mm. The method of Miller, Cooper and Miller (1976) was used to estimate aerosol contributions, leaching and absorption. Retranslocation estimates were 59.6 kg N ha ⁻¹ y ⁻¹ (55% of Requirement), 8.5 kg P (64% R), 42.0 kg K (56% R) and 1.2 kg Mg (14% R). Retranslocation was unchanged, but uptake increased with added N % P and decreased with added sawdust and glucose. Other typical effects of nutrient amendment were observed: with added N % P growth increased, current tissues had higher concentrations of N and P and litterfall decreased in the first year but was heavier in the second year: with added sawdust and glucose, growth declined but concentrations of N and P remained substantially the same.