Woody weed dispersal by birds wind and explosive dehiscence in New Zealand

Abstract

Age and distance from source were measured in southern New Zealand for plants of lodgepole pine and Darwins barberry and for seeds and plants of broom These species are dispersed by wind birds and explosive dehiscence respectively and annual spread rates of 1200 m 30 m and 12 m were obtained Broom seeds can be dispersed much further by animals or machinery Lodgepole pine spreads in the prevailing wind direction whereas directionality of spread of the other species is controlled by the behaviour of animal vectors Lodgepole pine and broom seedlings establish only in short vegetation but barberry can establish in scrub forest or pasture All three species produce seeds at four years of age Control measures should target outlier plants first