USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Research Topics Forest Management

Featured research

A surveyor stands near a large rock in the forest
Remapping the forest in 2008 using a laser and global positioning system.

Variable Density Thinning Study

The Variable Density Thinning study on the Stanislaus-Tuolumne Experimental Forest was established to test a new approach to forest thinning designed to produce a highly variable forest structure, similar to what forests of the Sierra Nevada once looked like. This variability made historical forests resilient to wildfire and the diversity of habitats benefited a wide variety of plants and animals. Areas treated with the 'High Variability' prescription are being compared to forests thinned to a more even crown spacing, as well as unthinned control plots, all with and without prescribed fire. Both types of thinning substantially reduced tree mortality during and after the 2012-2015 drought.

Methods of Cutting Studies
Stanislaus-Tuolumne Experimental Forest

"Methods of Cutting" studies to document the outcome of different harvest methods were among the earliest studies set up by pioneering U.S. Forest Service researchers. Twelve plots were installed on the Stanislaus National Forest between 1909 and 1930. Four of these plots were rediscovered and all trees were mapped again between 2007 and 2016, providing a compelling picture of dramatic changes that have occurred to forests in the absence of fire. Increased stand density, infilling of gaps, and high surface fuel loads contributes to many of the challenges our forests face today, including high fire hazard and susceptibility to bark beetle mortality.

Research Projects

Map of Blacks Mountain Experimental Forest
Blacks Mountain Ecological Research Project

The Blacks Mountain experiment is a large-scale project designed to evaluate the effects of stand structure, grazing and prescribed fire on various components of the forest environment. Researchers are studying vegetation response as well as the response of passerine birds, small mammals, bark beetles to the treatments.

Sampled foliage
Fuel Reduction Treatment Longevity Research

This project was designed to study the longevity of thinning by looking at the temporal impacts on biomass equations. Treatments that produce significant, but short-lived reductions in risk of severe wildfire may not be meeting the goals and objectives of managers.

Garden of Eden Slide showing plantation volume
Garden of Eden

Ponderosa pine is the most widely planted forest tree throughout California and southwest Oregon and is the usual reforestation species of choice following wildfire. The Garden of Eden experiment was established in 1986 to help us understand the response potential of planted ponderosa pine when competition, fertility, and insect pests are controlled from establishment through crown closure.

Pre-treatment (1998) stand conditions at the Goosenest AMA
Little Horse Peak (Goosenest AMA) Research Project

In the Goosenest Adaptive Management Area on the Klamath National Forest, the combined effects of fire suppression and differential cutting of pine have, over time, resulted in dense stands with a high proportion of white fir. Silvicultural treatments have the potential to accelerate development of late-successional attributes but the ecosystem responses to these treatments are untested.

Long-Term Soil Productivity network of experiments
Long Term Soil Productivity

The Long-Term Soil Productivity network of experiments began in 1989 as a "grass roots" proposal that grew to a national program of the USDA Forest Service. LTSP was founded to examine the long-term consequences of soil disturbance on fundamental forest productivity. The concept caught the imagination of others. Studies range from elucidating mechanisms controlling carbon capture above and below ground, to developing indices of soil quality practicable in monitoring.

SWO variant is for young mixed-conifer stands in southern Oregon.
Growth and Yield Simulation (CONIFERS)

CONIFERS is a young stand simulator for southern Oregon and northwestern California.

Growth and Yield Simulation (SYSTUM-1)

SYSTUM-1 is a prototype simulator designed to simulate growth of young plantations in northern California and southern Oregon (Ritchie and Powers 1993).

Related Research

Fire in Masticated Fuels Research Project
[Fire science topic area]

Mastication is an increasingly popular fuel modification technique involving the use of heavy machinery to shred standing live and dead shrubs and tree saplings into small chunks which are then dispersed on the forest floor as surface fuel. Research is being conducted to evaluate fire behavior when masticated fuels burn, develop custom fuel models for predicting fire behavior and effects, measure soil heating with burning at different soil moisture levels, and understand the vegetation response to mastication over time.