Pacific Northwest Research Station

Maybeso Experimental Forest

Introduction

The Maybeso Experimental Forest, located on Prince of Wales Island in southeast Alaska near Ketchikan, was established in 1956 to investigate the effects of clearcut timber harvesting on forest regeneration and regrowth, and on the physical habitat of anadromous salmonid spawning areas. The watershed was exposed to the first large-scale industrial clearcut logging in southeast Alaska and nearly all commercial forest was removed from the watershed, including the riparian zone, from 1953 through 1960. The present forest is an even-aged, second-growth spruce and hemlock forest.

The watershed is a broad U-shaped glacially sculpted valley with a single stream network. The stream flows through a floodplain composed of glacial till up to headwater tributaries to an elevation of 900 m. The area of the watershed is approximately 4,452 ha. Pink, chum, and coho salmon, and Dolly Varden, steelhead, and cutthroat trout are present throughout the main stream and tributaries. Wildlife species include several mammals and a variety of resident and migrant birds. Mammals include Sitka black-tailed deer, black bear, beaver, American marten, ermine, northern flying squirrel, Keen’s mouse, long-tailed vole, dusky shrew, and several species of bats. Forest and riparian birds include bald eagle, northern goshawk, and several species of owls, chickadees, wrens, warblers, and thrushes. Other birds found in the watershed are Steller’s jay, northwestern crow, raven, and spruce grouse. The species assemblages are representative of a second-growth forest in a temperate rainforest ecosystem.

The proximity of other watersheds in various stages of forest succession on Prince of Wales Island contributes to the significance of the Maybeso. The Old Tom Research Natural Area (an old-growth forested watershed) is located in nearby Skowl Arm and is accessible by boat or float plane. It can provide an old-growth control for some aspects of studies in the Maybeso. Current research in the watershed is focused on studies to provide information on the management of second-growth watersheds and for the development and evaluation of watershed restoration methods.

Climate

The Maybeso is part of a temperate rain forest and is characterized by cool, moist climate. The mean annual temperature is 6.7 °C and the average rainfall is about 2,740 mm annually. Temperatures rarely exceed 21 °C during the summer and seldom drop below -12 °C in the winter. Peak rainfall and streamflows generally occur during October and November and during the spring in April and May.

Soils

More than 90 percent of the valley soils are Tolstoi or Karta. The former are well drained and range from Entisols to Spodosols developed on steep slopes covered by colluvium on fractured bedrock; the latter are welldeveloped Spodosols. These form the weathered portion of the compact glacial till of much of the valley.

Vegetation

Sitka spruce and western hemlock are the dominant conifers. Other conifers include Alaska cedar and mountain hemlock. Red alder is the most common deciduous tree in the watershed. Common shrubs are Sitka alder, devil’s club, stink and trailing black currant, The Maybeso Experimental Forest (Alaska) salmonberry, blueberry, winterberry, and scarlet elder. More than 25 percent of the watershed was logged from 1953 through 1960. Nearly all of the commercial forest was harvested and most of the present forest is 40 to 50- year-old, second-growth Sitka spruce or western hemlock. Alder is the dominant tree species in landslide tracks, abandoned roads, and parts of the riparian zone.

Long-Term Data Bases

A set of scale maps of the stream was completed and updated annually from 1949 through 1960. Secondgrowth thinning plots established shortly after timber harvest are remeasured periodically. Juvenile salmonid populations have been sampled periodically from the early 1980s to the present. Discharge and temperature records were made from 1949 through 1963 for most months; however, measurements were made only from April to October from 1948 through 1952.

Research, Past and Present

The Maybeso research program is designed to evaluate aspects of forest regeneration, riparian succession and evolution of stream channel morphology, and response of salmonid populations to changes in large-wood density and distribution. Several of these studies cover a period of more than 40 years. During the past 20 years, research on the watershed has evolved from studies of salmonid spawning habitat to broader studies of stream and riparian habitat as it moves through succession following timber harvest. The focus has been on changes in stream habitat as it relates to large-wood and its effect on juvenile salmonid populations. These studies have established a long-term (> 40-year) analysis of stream channel evolution. An extensive and thorough investigation of slope stability was conducted and completed during and shortly after logging in the watershed, as was an analysis of the geology of the watershed. These studies have continued intermittently during the past 30 years. Plots to evaluate long-term growth and silviculture treatments on the second-growth forest are located throughout the watershed. Streamflow and temperature data also have been collected intermittently during the past 40 years. Recent research in the watershed has emphasized land-management activities on steeper slopes and the role of alder in forest productivity.

Major Research Accomplishments and Effects On Management

Research on the Maybeso watershed has focused on hydrology, slope stability, silviculture, and fish habitat. Results from research have contributed to guides for timber harvest practices on steep slopes, thinning regimes for second-growth spruce forests, and management of large-wood in streams.

Collaborators

Researchers from the following institutions have collaborated on studies at the Maybeso: University of Washington, University of Alaska, Michigan State University, University of Michigan, Montana State University, Oregon State University, and University of British Columbia.

Research Opportunities

There are opportunities for research on the following topics:

• Second-growth forest succession
• Effects of intensive silviculture of forest and watershed succession and ecology
• Watershed restoration

Facilities

A 12-person bunkhouse was completed in 2002 at Hollis; two other older buildings there provide storage and work space. The facilities at Hollis are located about 3 km from the Maybeso.
Lat. 55° 29' 13" N, long. 132° 39' 59" W

Contact Information

Maybeso Experimental Forest
USDA Forest Service
Pacific Northwest Research Station
Juneau Forestry Sciences Laboratory
2770 Sherwood Lane Suite 2A
Juneau, AK 99801-8545
Tel: (907) 586-8811
http://www.fs.fed.us/pnw/exforests/maybeso/index.shtml

¹Information has been updated since original publication.

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