Friday, June 28, 2002
Tour Hosts: John Shaw, PhD, Research Scientist, USU
James N. Long, PhD, Professor of Silviculture, USU
Welcome to the T .W. Daniel Experimental Forest. Administratively, the forest was established in 1936. One section belongs to USU and three sections to the USDA Forest Service. The TWD Forest has a long history of use for teaching, research and demonstration. Early research, as represented by more than 125 papers, dissertations and theses, provides a solid background for ongoing basic and applied research in forest ecology, silviculture, disturbance ecology and ecosystem management.
The principal forest types are spruce-fir, lodgepole pine and aspen, with interspersed meadows and shrub-forb-grass uplands. Engelmann spruce and subalpine fir are the dominant late successional species throughout most of the area. Aspen and lodgepole pine are the major early successional species. Stand ages range from recently regenerated lodgepole and aspen to nearly 300 year old spruce-fir stands. Most stands are 100-150 years old.
The lodgepole pine trees forming the overstory of this stand were established following a large (i.e. > 600 acres) "stand replacing" fire in 1847. Seed came from surviving trees in the neighborhood. With the exception of some very light research thinning, this stand has developed naturally for about 150 years.
Parts of the complex of stands originating after the 1847 fire had a non-lethal understory burn in 1903. This second fire killed some trees and scarred others. Essentially, the 1903 fire thinned parts of the stand and the reduced density has resulted in larger trees with large diameter branches. Northern Goshawks seek out Stands with this sort of structure --not too dense, not too open.
Two young lodgepole-dominated stands:
a) The first stand regenerated naturally following a complete clearcut -30 years ago. As a regenerating method this was highly successful. However, as a mimic of a typical wildfire it falls short in two major ways --it lacks any residual structure (snags, residual trees, coarse woody debris) and, at 20 acres, it is much smaller than most natural fires in lodgepole pine.
b) The second stand was naturally regenerated following a "shelterwood-with-reserves" or "green tree retention" harvest about 15 years ago. Trees were retained as legacies of the previous stand. The resulting structure and tree species diversity is a better reflection of the mixed and variable severity wildfires typical of the lodgepole pine type in this area. However, the extent of this disturbance (about 20 acres) is still much smaller than typical of wildfires.
A thinning demonstration was installed in part of the first stand (a) in 1985. Five treatments, including unthinned control plots, ranged from 360 to >10,000 trees/ac (900 to >25,000 trees/ha). In 1999, a study of the use of different stand densities by snowshoe hares was started in the thinned plots and surrounding stand. This pilot study produced promising results and the study was expanded to 17 stands on 4 national forests (see hare handout below).
Data and analysis of hare cover study. As expected, hare use (as indicated by pellet count) is higher where cover is greater (top). However, stem density does not necessarily increase horizontal cover when the density of lower needles is reduced by branch pruning or defoliation. Analysis of pellet presence/absence (bottom) suggests that areas with at least 2800 trees/ha (1130 trees/acre) are preferred by hares: 91% of plots with stem density >2785 trees/ha had pellets present, while 50% of plots with stem density <2785 trees/ha had pellets present. Within both ranges of stem density, pellets were found more frequently in plots greater horizontal cover at snowpack level (2m above ground).
The reference condition for the lodgepole pine type within the analysis area is based on a mixed and variable severity fire regime with a fire-free interval between 100-200 years. Fires were of various sizes, but generally > 600 acres. Mixed-severity fires produced variation in pattern resulting from low to high severity burning. Differences in fire behavior created a range of density of surviving trees, a range of regeneration density and a range of post-fire tree species diversity (i.e., pure lodgepole pine to mixed conifer and aspen).
Silvicultural elements intended to capture this reference condition:
1) Treatment area is large (~200 acres) and plans were to eventually raise this to 600 acres;
2) Various reproduction methods --
a) traditional (complete) clearcut simulating a high severity burn without surviving trees (10% of unit)
b) clearcut-with-reserves with reserves ranging from single trees up to 1 ac (0.4 ha) patches, simulating medium severity (80% ofunit)
c) uniform shelterwood simulating a low severity burn leaving many surviving trees (10% of unit)
Sale history Slideout sale: 120 acres (49ha), < 10 acres/patch (4ha) cut, 6746 ccf/3.6 mmbf(18,900 m3) $280/mbf($53/m3), completed in 1999.
Bear Hodges: 200 acres (81 ha), 6547 ccf/3.3 mmbf (18,300 m3), $114/mbf ($21/m3),logging started Sept. 2000, finished Sept. 2001.80% lodgepole pine by volume, logs to Belgrade, MT.
Stop #4 (optional, after lunch)
After lunch John Shaw and Jim Long took those that remained on an optional tour of the T.W. Daniel Experimental Forest, where the group viewed old growth spruce-fir and a 300-year old aspen that John Shaw has documented. This is currently the oldest aspen on record.
Click here or on the image to the left to see a larger picture of this tree.