A model integrating seed source adaptation and seed use

A conceptual model that considers the performance (adaptability) of a seed source (=an origin) and the location or range of its deployment is developed employing the Cauchy function. The model assumes that there exists an optimal site type for each provenance origin (genetic material), and that loss in performance is a function of the distance (a measure of increasing maladaptation) from the optimal site. The model requires the estimate of three parameters: a site requirement value that measures site type in one dimension; a measure of optimal performance; and a flexibility measure of the width of seed source adaptability. The Cauchy function has a known integral, thus the average adaptability over a range (a possible seed use zone) can be mathematically evaluated. The model was also extended to seed orchard crops representing progeny of parents of variable origins. Scots pine information in Sweden was used to demonstrate possible applications of the model.