Research at Bonanza Creek Experimental Forest

Past and current research

Research activity within the area began even before formal establishment of the Experimental Forest. See the Bonanza Creek LTER bibliography for a complete listing of research publications resulting from work in BCEF. Much of the early research was conducted by scientists from the Institute of Northern Forestry (INF; now Boreal Ecology Cooperative Research Unit), Pacific Northwest Research Station. Early research by Gregory on white spruce seed production began in 1958, and was continued by Zasada from 1969 through 1984. From 1957 until 1966, Gregory and other INF personnel conducted destructive sampling and stem analysis for the development of growth and yield tables for white spruce, aspen, and birch. Both floodplain and upland stands within BCEF were used extensively. Zasada established demonstration plots for different silvicultural systems on an upland white spruce site in 1972, and with others, considered various aspects of natural regeneration including seedfall, seedling survival, density and growth, nutrient status, and competition. Sprout and sap production in birch stands has also been studied. Beginning in 1962, INF and the University of Alaska cooperated in studies of the effects of red squirrel foraging on white spruce cone and seed production. This work was later expanded by Wolff to include red squirrel response to various silvicultural treatments.

©Knut Kielland, Photo

Between 1964 and 1967, Heilman, University of Alaska, conducted studies of nutrient relationships in birch and black spruce stands on north-facing slopes in BCEF. This work was expanded on by Van Cleve, University of Alaska, to include above and below-ground biomass and nutrient cycling in white spruce and birch stands on all aspects. Viereck, Foote, and others have utilized numerous permanent plots to study species composition, successional relationships, and soil temperature fluctuations. BCEF has been used extensively in the study of forest insect biology and management. Research by Warner, Beckwith, and others has focused on the spruce and Ips beetles, large aspen tortrix, spear-marked black moth, and the larch bud moth.

More recently BCEF has been the site of studies of floodplain soil moisture dynamics and formation of salt crust on freshly-deposited alluvium (Salt Affected Soils), forest reestablishment following wildfire (Rosie Creek Burn), insect and disease dynamics following wildfire, and tree species provenence tests. In 1987, BCEF joined the network of Long-term Ecological Research (LTER) sites, studying successional processes in the well represented taiga forests at the Experimental Forest (LTER1 and LTER2). In 1996, the Institute of Northern Forestry was closed and the Boreal Ecology Cooperative Research Unit (BECRU), PNW Research Station, established.

Many of these projects are described more fully in the Bonanza Creek LTER data catalog. Project details and datasets are archived and generally are available for secondary use.

Research accomplishments

Research at the BNZ LTER site has contributed substantively to understanding the relationship between "independent" state factors and internal ecosystem dynamics in causing successional change in the boreal forest of Alaska. Major findings of the program are: Species effects are strong in the boreal forest; Successional changes in species composition are not a simple consequence of changes in competitive balance but involve species-driven changes in biogeochemistry and the physical environment; Vertebrate herbivores are a powerful force driving successional change through their effects on plant competitive interactions and biogeochemistry; Succession influences exchanges of CH4, CO2, water, and energy in ways that could feed back to climate. This research on succession raises important questions about the broader regional context in which succession occurs. The current phase of LTER addresses the question: How do changes in climate and disturbance regime alter the functioning of the Alaskan boreal forest?