H.J. Andrews Experimental Forest

Climate

The climate at the H. J. Andrews is cool and wet in winter and warm and dry in summer. Annual precipitation is about 2,500 mm at low elevations, falling mainly as rain at low elevations and as snow at upper elevations.

Soils

Soils are primarily Inceptisols, with local areas of Alfisols and Spodosols derived from mainly andesite volcanic bedrock. Surface horizons are commonly loamy but may be stony at depth and shallow on steep slopes.

Vegetation

Douglas-fir-western hemlock forest dominates at lower elevations and Pacific silver fir forest at upper elevations. Forest age classes include 150- and 500-year-old stands developed after wildfire, and plantations dominated by Douglas-fir established after clearcutting since 1950. Other forest types and age classes exist in neighboring areas, including within RNAs.

Plotting the Future by Monitoring the Past - Click here to visit the story map in full screen.

The H. J. Andrews is located 50 miles east of Eugene, Oregon, in the Cascade Mountains and is a 2-hour drive from Corvallis, where many scientists working at the forest have main offices. The headquarter facilities include office, laboratory, and living facilities.

Address:

H.J. Andrews Experimental Forest

P.O. Box 390

91991 Blue River Reservoir Road

Blue River, OR 97413

Research, Historical & Present

Studies in the first two decades of the H. J. Andrews’s history emphasized basic characterization of the forests and soils and analysis of effects of forestry practices, including effects of clearcutting with and without burning and various partial cutting practices on nutrients, streamflow, and sediment yield from small watersheds. In the 1970s, ecosystem studies expanded the characterization of patterns of and controls on vegetation across the landscape, stream ecology, disturbance processes, and hydrology and nutrient cycling within small watersheds. Basic work on old-growth forests and northern spotted owl ecology took place during this decade. Since 1980, research under the LTER program has focused on the question “how do land use (principally forestry and roads), natural disturbances (principally fire and floods), and climate variability affect key ecosystem properties, especially hydrology, biological diversity, and carbon dynamics”?

Research Opportunities

The H. J. Andrews is managed as an open national and international research and education resource. There are many research and education opportunities. Contact the director or participating scientists for further information.

Numerous long-term data bases are available on the H.J. Andrews Web site. These include the amount and chemistry of precipitation and streamflow from three sets of experimental watersheds; vegetation change in plots of various types, including 1-ha mapped reference stands representing the vegetation types of the areas; and data from long-term experiments, such as the 200-year log decomposition experiment.