Repository logo
 

Forest regeneration trajectories in mountain pine beetle-disturbed forests of Rocky Mountain National Park

Date

2010

Authors

Diskin, Matthew, author
Rocca, Monique E., advisor
Romme, W. H. (William H.), committee member
Sibold, Jason S., committee member

Journal Title

Journal ISSN

Volume Title

Abstract

A severe mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic in western North America has caused widespread mortality of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) and drastically altered subalpine forest structure and composition over large areas. My research describes possible future forest regeneration trajectories by documenting tree survivorship in Rocky Mountain National Park, CO, and then projecting future forest conditions using an established forest growth model, the Forest Vegetation Simulator. In 2008, I measured stand structure and tree species composition in lodgepole pine-dominated forests in the western portion of the Park. I defined five lodgepole pine forest types that varied with respect to the abundance of seedlings and non-lodgepole pine species. These forest types formed the foundation for further analyses to describe variability in post-epidemic forest regeneration trajectories. Chapter One documents surviving forest stand structure and composition in the Park, and shows that surviving trees, including larger canopy trees, saplings, and seedlings, were plentiful in most of the post-epidemic forests. Lodgepole pine remained the dominant species in most areas, but modest increases in the relative abundance of subalpine fir (Abies lasiocarpa (Hook.) Nutt.), Engelmann spruce (Picea engelmannii Parry ex Engelm.), and aspen (Populus tremuloides Michx.) had occurred. Forest structure and composition varied considerably among the five forest types after the epidemic, setting the stage for variable future forest regeneration trajectories that were explored in Chapter Two. Future forest conditions were projected over a 100 year time period and are presented in Chapter Two. The projections show that the beetle-disturbed forests remain forested in the future, and emphasize that the most important mechanism for forest renewal is the release of surviving trees, rather than post-epidemic tree seedling establishment. Projected future forest conditions varied depending on the forest type, but indicate that basal area and quadratic mean diameter recovery occurs within 40-100 years in most areas. Spruce, fir, and aspen become dominant in the projected future forests on approximately 60% of the landscape, while lodgepole pine remains dominant in the forests where it formed pure stands prior to the epidemic.

Description

Department Head: Michael J. Manfredo.

Rights Access

Subject

Forest regeneration -- Rocky Mountain National Park (Colo.)
Trees -- Seedlings

Citation

Associated Publications