Experimental studies of potential improvements in the forest regeneration capabilities of 'seed-containing aerial darts'

Abstract

An evolving forest regeneration technique, based on the use of a 'seed-containing aerial dart' (SCAD), provides for the delivery of seeds by helicopter through the distribution of darts, which serve as ground-penetrating containers for individual seeds. While many biological and technological aspects of this aerial sowing technique have been previously documented, the hitherto unpublished results of some growth experiments, carried out over a five-year period, are believed to offer the key to any future development. These simulated field experiments, although small in scale, demonstrate means for greatly improving the prospects for regeneration using aerial darts. Such means include dart configuration changes to provide for axially spaced seeds and the addition of slow-release fertilizer, when not in direct contact with seeds within the growth medium. Darts sown in the fall on mechanically undisturbed ground are shown not to be subject to frost heaving and lead to much earlier germination and faster growth than occurs with spring sowing. The presence of a surface layer of organic material is shown to be extremely beneficial in promoting vigorous seedling growth. The results confirm the potential applicability of the technique to sites, such as recently burned areas, with these characteristics, where acceptable regeneration performance is not an unrealistic objective.