Controlling the spread of plant invasions: The importance of nascent foci.
A simple geometric model for one-time control was expanded to incorporate more realistic aspects of invasion and used to evaluate the spatial growth of an invasing plant and various strategies for its control. The initial population comprised a single large expanding focus but had the potential for the continual establishment of new foci. The area occupied through the establishment and expansion of these satellite foci was compared to the area occupied by the initially large or main focus under varying regimens of repeated control, in which either the area of the main focus was reduced and/or some satellites were destroyed. Whether varying growth rates for the foci, rates of satellite establishment, the level of reduction of the main focus or the intensity of satellite detection and destruction, the overall effectiveness of control measures was greatly improved by destroying even 30% of the satellites.