Ground vegetation biocontent and net production in a deciduous woodland.

Biocontent of the above-ground parts of ground vegetation in an alder-birch woodland was between 75 and 581.3 Kcal/m2 (16.05 and 137.70 g/m2). Species peaks did not necessarily coincide with the highest values for total ground vegetation. Ground vegetation litter biocontent was 1848.4 Kcal/m2 at the beginning of the study (April 1966) but rapidly fell to near 700 Kcal/m2 and remained near this level until April 1968. Net production by the above ground parts of the ground vegetation was 1016 Kcal/m2/yr (277.86 g/m2/yr) and 1142 Kcal/m2/year (280.20 g/m2/yr) in 1966-1967 and 1967-1968 respectively, measured as mortality plus net biocontent changes. These estimates were compared with those based on biocontent changes. Ground vegetation net primary production was not much smaller than tree litter fall (circa 1450 Kcal/m2/yr).