Last week I attended a U.S. Forest Service training in Central Point, OR where I took a deep dive into silvicultural modeling with the Forest Vegetation Simulator (FVS) software. My fellow classmates represented the USFS, Bureau of Land Management, state natural resource agencies, private industry, and forestry consulting firms. Attendees were mainly from California and Oregon, and are managing their forests with consideration for spotted owl habitat, fuels reduction, and reduced fire risk. Some, however, had traveled from the southern US or from the northeast, and were concerned with improving tree health and financial returns by introducing pre-commercial thinning in loblolly pine plantations, or regeneration success for oak species. The workshop was a great opportunity to learn about the myriad challenges facing forest managers across the country, and to envision what their interventions might yield.
FVS is a forest growth and yield model utilizing common stand exam or inventory data to model a forest stand. Employing our current knowledge of species growth rates, competition, and the effects of insects and disease, the model predicts the growth and mortality of each tree in the stand over time. The user can manipulate baseline outcomes by adding management actions, be they reforestation, thinning, commercial harvest, prescribed burning, salvage operations, etc. As with any model, assumptions are unavoidable and the results are not definitive. However, they can be extremely helpful in evaluating the relative benefits of active management, and in communicating these benefits.
Over the course of the week, I practiced my budding modeling skills on a stand in the Stanislaus National Forest. Examining management effects is increasingly relevant as the Sierra Institute prepares to take on a bigger role in forest management in the northern Sierra Nevada and southern Cascades through the South Lassen Watersheds Group effort. The model is far from perfected and makes a number of assumptions, but was successful in reducing fire risk, improving carbon storage, and increasing the average diameter and height of trees in the stand. Modeled management included thinning from below, mastication, and prescribed burning, typical treatments for fuels and fire risk reduction in the Sierra Nevada. An animation of the model is included below:
And, as proof that I didn’t spend the entire week in front of a computer, here is a picture from the top of Upper Table Rock. Just north of Central Point, this andesitic mesa (and its neighbor, Lower Table Rock) offer great views of the Rogue River Valley and Mt. McLoughlin.