The Nutrient Content of Tree Stem Flow and Ground Flora Litter and Leachates in a Sessile Oak (Quercus Petraea) Woodland

Abstract

The total annual fall of nutrients (kg/ha) to the soil of an oakwood (Q. petraea) from all (litter + rainfall) sources was 70-90 N, 4-60 P, 51.99 K, 57-11 Ca, 19-19 Mg, 93-41 Na and 6943 organic matter. The C content of all the litter was 3362-2 kg/ha and the energy content 31-85 x 106 kcal/ha. The Pteridium aquilinum ground flora played an important role in the K cycle, its total contribution of this element in both its litter and rainfall leachates being 31-4% of the total K falling from all sources. Both the trees'' and the Pteridium foliage extracted inorganic N from the rainfall as it passed over them. The stem flow waters contributed small but appreciable amounts (3-6% of the total fall) of K, Ca, Mg and Na. Nutrient and polyphenol concentrations in these waters were relatively high and their potential importance to the tree stem epiphytes is discussed. The Pteridium intercepted 6-38 cm of rainfall, equivalent to 3-7% of the annual incident rainfall. The stem flow accounted for 2-1% of the annual throughfall water quantity. If the ground flora was ignored, the estimate of the absolute quantity of water intercepted would have been 26% too low.