Magnitude of nutrient influxes from atmospheric sources to a Central American Pinus caribaea woodland.
Abstract
The following influxes of macro-nutrients in bulk precipitation were measured during 1 year in the Mountain Pine Ridge savanna, Belize (kg ha-1): Ca 1.96; Mg 0.28; K3.40; Na 9.34; and P 0.12. newline˜The quantities of water-soluble nutrients in aerosols caught by an artificial filter over the same period were also measured, and these measurements converted to estimates of filtration by canopies of Pinus caribaea Morelet, var. hondurensis, after calibration of the filter catch on that by pine foliage. Annual canopy filtration by natural and thinned 30-year-old pine strands were found to comprise only 8.1-37.8% and 3.2-15.9% of bulk influx, respectively, with Ca and K showing little augmentation from this source and Mg the greatest relative to bulk influx. newline˜The influx of K from atmospheric sources is probably adequate to meet the requirement for this element by the first cycle of pine-stand development in this area, but the influx of other elements is insufficient and tree growth is presumably drawing upon soil reserves. newline˜However, conventional timber harvesting at the end of the first rotation will remove only a portion of accumulated nutrients and, provided that the remainer are not lost from the site, subsequent rotations can be sustained by the atmospheric accessions measured.