Treesearch

Oak decline has been recorded on oak forests throughout the Ozark Plateau of Missouri since the 1970s, but severe drought in the late 1990s, combined with the advancing age of the Ozark forests, has intensified the levels of crown dieback and mortality beyond historical levels. The purpose of this project was to determine whether the Forest Vegetation Simulator (FVS) model could accurately predict the effect of oak decline on the Mark Twain National Forest (MTNF). Forest Inventory and Analysis (FIA) data were used to benchmark mortality magnitude and to adjust FVS growth projections. Data...

The Southern Variant of the Forest Vegetation Simulator (FVS-SN) is made up of individual submodels that predict tree growth, recruitment and mortality. Forest managers on Ft. Bragg, North Carolina, discovered biologically unrealistic longleaf pine (Pinus palustris) size-density predictions at large diameters when using FVS-SN to project red-cockaded woodpecker (Picoides borealis) habitat. Inventory data from Ft. Bragg indicated the mortality submodel was responsible for the over-predictions. Three approaches to remedy longleaf pine mortality predictions in FVS-SN were explored: (1) using...

Meteorological observations at Fort Valley Experimental Forest began with its establishment as early silvicultural research made heavy use of meteorological data. The Fort Valley weather data represent the longest climatological record for northern Arizona with records dating back to 1909. Importance of long term meteorological records and access to the weather record are described.

Climate change-global warming and changes in precipitation-will cause changes in tree growth rates, mortality rates, the distribution of tree species, competition, and species interactions. An implicit assumption in FVS is that site quality will remain the same as it was during the time period observations used to calibrate the component models were made and that the site quality will not be affected by climate change. This paper presents evidence of the impacts of climate change on forests and argues that FVS needs to be revised to account for these changes. The changes include modificatio...

This paper presents a vascular plant species list for two sites that are part of a long-term study exploring the effects of varying fire intervals on forest characteristics including the abundance and composition of understory vegetation. The Chimney Spring study area is on the Fort Valley Experimental Forest near Flagstaff, AZ and the Limestone Flats study area is on the Long Valley Experimental Forest, 90 km (56 mi) southeast of Flagstaff. Since 1976 (Chimney Spring) and 1977 (Limestone Flats), three replicates of each of seven burn intervals (1, 2, 4, 6, 8, 10 years, plus unburned) have...

Predictions based on the Gypsy Moth Event Monitor were compared to remeasurement plot data from stands receiving gypsy moth defoliation. These stands were part of a silvicultural treatment study located in northern West Virginia that included a sanitation thinning, a presalvage thinning and paired no-treatment controls. In all cases the event monitor under predicted the initial mortality for all stands in terms of trees per acre. Prediction errors, with regards to trees per acre, were largest in stands receiving the heaviest defoliation. In terms of basal area prediction, those stands...

The ability of the PrognosisBC (Version 3.0) growth model to predict tree and stand growth was assessed against a series of remeasured permanent sample plots, including some which had been precommercially thinned. In addition, the model was evaluated for logical consistency across a variety of stand structures using simulation. By the end of the evaluation process, we were pleased with the performance of the model. Some of the less obvious benefits of growth model evaluation and the value of using multiple approaches when evaluating growth models are discussed.

The Westwide Pine Beetle Model and the Fire and Fuels Extension were used to simulate a mountain pine beetle outbreak under different fuel treatment scenarios on a 173,000 acre landscape on the Deschutes National Forest. The goal was to use these models within ArcFuels to analyze the interacting impacts of bark beetles and management activities on landscape fuel dynamics. Issues pertaining to modeling the complex inter-relationships of fire, bark beetles, and fuel dynamics are discussed, including: thinning effects on inter-stand bark beetle migration; relationships between beetle migration...

Prior to the 1990s, a primary focus of vegetation management on National Forest System (NFS) lands was commodity production. While the production of goods is still important, the last 20 years has seen an emphasis in the restoration of ecosystem function and resiliency. This is illustrated by a decline of more than 80% in NFS timber production since the late 1980s. The current Forest Service focus on ecological restoration reflects both changing public values, and the current ecological conditions on NFS lands. Ecological restoration is not restoring land to some predetermined point in...

The purpose of this analysis was to use long term permanent plots to evaluate the short-term predictive capability of the Western Root Disease Model extension (WRDM) of the Forest Vegetation Simulator (FVS) in central Oregon mixed-conifer forests in project planning situations. Measured (1991–2002) structure and density changes on a 100-acre unmanaged area in south-central Oregon were compared to those predicted by the Southern-Oregon Northern-California variant (SORNEC) of FVS and the WRDM. Within the study area there were 149 variable-radius plots within 12 stands. Predictions were...