AUTHORS: Sarah Nodskov1, Caleb Roberts2, 3, Victoria Donovan2, Emma Keele5, Dirac Twidwell2, Craig Allen3, Larkin Powell1, Dave Wedin1, David Angeler4
1 University of Nebraska Lincoln, School of Natural Resources, Hardin Hall, Lincoln, Nebraska 68583-0961
2 University of Nebraska-Lincoln, Department of Agronomy & Horticulture, Keim Hall, Lincoln, Nebraska 66583-0915
3 Nebraska Cooperative Fish and Wildlife Research Unit - USGS, Hardin Hall, Lincoln, Nebraska 66583-0984
4 Swedish University of Agriculture Sciences, Department of Aquatic Sciences and Assessment, Uppsala, Sweden PO Box 7050
5 University of Nebraska Kearney, Department of College of Natural & Social Sciences, Department of Biology, Kearney, Nebraska 68849
ABSTRACT: The historical diversity of ecological communities within Ponderosa Pine systems has been attributed to unique habitat structures spawned from mixed-severity fires occurring over time creating asynchrony in habitats. However, because current management tactics in Ponderosa systems focus on complete fire elimination or allow only low-severity fires, the creation of such habitats may be inhibited. We compared multivariate post-fire forest structure resulting from 27- and 10-year-old mixed-severity wildfires in the Pine Ridge region of northwestern Nebraska. In stratified-randomly distributed plots, we measured coarse woody debris (CWD) area cover, tree cavity height, tree cavity width, tree density, tree diameter at breast height (DBH), and decay classes of trees and CWD. We found both time-since-fire and fire severity created unique habitat structures (P = 0.001, F = 9.3867; P = 0.001, F = 21.7979, respectively), although fire severity was most influential. Comparing both sites, high severity differed in the decay class of snag and CWD. Multiple comparisons found habitat structure varied between all fire year-fire severity combinations (all P > 0.002) except in unburned forests, High2006 vs. Moderate2006 (P = 0.104), Low2006 vs. Moderate2006 (P =1.365), and High1989 vs. Moderate1989 (P-value: 1.888). Our results suggest that wildfires create multiple unique forest structures, thus providing diverse niche space for various ecological communities. Future management of Ponderosa Pine systems in the Pine Ridge should consider the highly diversified ecological niches fire creates when applying pre- and post- fire management methods.
