The Gradient Model

Abstract

To describe the distribution ofthe vegetation, fuel, and community properties, the Glacier National Park gradient model simultaneously uses six continuous environmental gradients, including:

• 1) Elevation

• 2) Topographic-moisture

• 3) Time since the last bum

• 4) Primary succession (soil and vegetative cover development)

• 5) Drainage (lake and geographic moisture) influence

• 6) Alpine wind-snow exposure

and four additional categories of variation and disturbance:

• 7) Intensity of the last bum

• 8) Slide disturbances (fellfields, avalanche fields, mud and rock slides)

• 9) Hydric disturbances (floodplains, bogs, marshes, lake edges)

• 10) Influences of heavy winter ungulate grazing