Litter production and accumulation in naturally seeded, old-field, Virginia pine (Pinus virginiana Mill.) stands

Litter-fall and litter-layer data were collected from stands of 7, 13, 19 and 36-year-old naturally seeded, old-field, Virginia pine. The pattern of yearly litter-fall was highly seasonal with maximum needlefall occurring during the fall months. Estimated annual total litterfall ranged from2.90mt/ha dry weight in the 7-year-old stand to 5.49 mt/ha dry weight in the 36-year-old stand: The percent annual contribution of non-needle material to the total increased from 16.5% in the 7- year-old stand to 43.9% in the 36-year-old stand.

Maximum litter-layer dry matter weight of 139 mt/ha and volatile matter weight (loss on ignition at 525°C) of 52 mt/ha occurred in the 36-year-old stand. The depth and maximum water storage of the litterlayer increased with stand age to a maximum of 5.34 cm and 1.42 cm respectively in the 36-year-old stand.

Several models characterizing the accumulation and decomposition of litter were developed. The best fit model assumes that litter-fall changes with time and that the litter is split into two fractions with ea.ch fraction decomposing at a different fixed annual rate. This model supports the fact that litter-fall is a mixture of different components such as cellulose and lignin which are known to decompose at different rates.