Craig G. Lorimer

Professor

Russell Labs
1630 Linden Drive
Madison, WI 53706

Phone: 608-262-6187
E-mail:clorimer@wisc.edu

Current Open Positions

No openings for assistantships are available for the academic year 2007-2008.

Current Projects

Ecology and Restoration of White Pine in the Northern Hardwood Forest

Hemlock-northern hardwood stands in the Lake States and elsewhere often contain very large, weathered stumps of white pine, still visible more than 50 years after they were cut. These "supercanopy" pines towered high above the other trees and were important nest sites for eagles, osprey, great blue heron, and other species. The original relative abundance of these trees is not known. During the late 19th and early 20th centuries, loggers "cherry picked" the pines out of these forests and systematically eradicated the seed source. So natural regeneration of pine is unlikely even when suitable environmental conditions are present.

This project will have 3 main objectives, each using a different methodological approach. We will estimate how much pine existed in the presettlement northern hardwood forest using historical land survey records, and also use these records to verify the specific kinds of soils and habitats on which pine was found. Second, we will investigate the age structure and disturbance history of remnant old-growth pine stands to determine how pine perpetuated itself in this relatively nonflammable matrix of mesic hardwoods. Third, we will experimentally investigate the possibility of restoring white pine to northern hardwood stands by planting pines in openings of several different sizes.

Funding: McIntire-Stennis Cooperative Forestry Research Program.
Status: In progress.
Research Assistant: Robert Fahey, Ph.D. Candidate

Ecology and Silviculture of Multi-cohort Hemlock-Hardwood Forests

A basic tenet of ecosystem management is that silvicultural systems should mimic the pattern of natural disturbance in order to sustain ecosystem processes and provide habitat conditions suitable for maintenance of biological diversity. The purpose of this project is to determine the pattern and impact of moderate-severity natural disturbances in the Upper Great Lakes region, and to study the long-term development of stands impacted by these disturbances. This information will be used to design sustainable silvicultural systems for managing similar areas as multi-cohort stands. The project will use a combination of new field work, re-measurement of long-term permanent plots, and use of existing forest models.

Funding: McIntire-Stennis Cooperative Forestry Research Program
Status: In Progress
Research Assistant: Jake Hanson, Ph.D. Candidate

An Experimental Assessment of the Effects of Canopy Gaps on Understory Dynamics

Many short-term observation studies have been conducted on the role of canopy gaps in fostering new tree recruitment in forests. However, because canopy recruitment is a long-term process, and conditions in observational studies are not well controlled, much of the evidence is inconclusive. This study is being initiated to provide long-term experimental evidence on the effects of canopy gap size on seedling establishment, sapling recruitment into the canopy, and crown and stem growth of the adjacent mature trees surrounding the gaps.

This project is part of an interdisciplinary team project that will examine effects of canopy gap manipulations and coarse woody debris levels on microclimate, soil processes, microbes, litter quality, understory and overstory vegetation, lichens, and invertebrates. Initial funding has been received by the team to set up the experimental design on a tract of northern hardwood forest in the Flambeau River State Forest, Wisconsin.

Funding: National Research Initiative, USDA Competitive Grants.
Status: In Progress.
Research Assistant: Jake Dyer, MS. Candidate.

Experiments on the Perpetuation of Oak Forests

Lack of oak regeneration, and displacement of oak forests by maples and other species, is a chronic and widespread problem over much of eastern North America. A long-term experiment in southwestern Wisconsin was initiated in 1985 to test the effectiveness of three different treatments in fostering the development of oak seedlings. These treatments included removal of tall understory trees of competing species, use of herbicide to control low vegetation and resprouting of competitors, and underplanting of oak seedlings. Eight different combinations of these treatments were evaluated. Enough time has elapsed that the "seedlings"l; are now sizable pole trees, and it is now possible to make some fairly definitive conclusions about the success or failure of each treatment. This project represents one of the longest oak regeneration experiments in the country.

Funding: Kickapoo Valley Reforestation Fund
Status: Completed
Research Assistant: Nicholas Povak, M.S.

Related Publications:
Lorimer, C.G. 1993. Causes of the oak regeneration problem. Pp. 14-39 in : Oak Regeneration: Serious Problems, Practical Recommendations. USDA Forest Service General Technical Report SE-84.
Lorimer, C.G., J.W. Chapman, and W.D. Lambert. 1994. Tall understory vegetation as a factor in the poor development of oak seedlings beneath mature stands. Journal of Ecology 82: 227-237.

Group Selection as an Alternative to Even-Aged Management in Hemlock-Hardwood Forests: Effects on Species Composition, Productivity, and Aesthetics

Although group selection has been recognized as a standard silvicultural method for more than a century, it has rarely been implemented on a large scale in North American forests. Research on the topic has likewise been meager. However, public opposition to clearcutting in recent decades has prompted a renewed look at group selection as an aesthetically acceptable alternative to even-aged management.

Mature and old hemlock forests are a valuable aesthetic resource and provide a unique habitat important for maintaining regional biological diversity. Hemlock forests have traditionally been managed by the even-aged shelterwood method, which has some undesirable features from a conservation perspective. The purpose of this study is to examine the use of single-tree and group selection as an alternative to the shelterwood method. We are investigating the effects of single-tree and group selection on tree species composition, productivity, and aesthetics of hemlock stands in the Menominee Indian Reservation of northeastern Wisconsin. Tree species composition, dimensions, and growth rates have been analyzed from single-tree and group selection openings spanning a wide range of sizes and ages. A computer model (CANOPY), which includes "three dimensional" depiction of forest stands, is being developed to examine long-term effects.

Funding: McIntire-Stennis Cooperative Forestry Research Program
Status: Complete
Research Assistant: Christopher Webster, Ph.D.

Publications:
Webster, C.R. and C.G. Lorimer. 2002. Single-tree versus group selection in hemlock-hardwood forests: are smaller openings less productive? Canadian Journal of Forest Research 32: 591-604.
Webster, C.R. and C.G. Lorimer. 2002. Comparative growing-space efficiency of four tree species in mixed conifer-hardwood forests. Forest Ecology and Management (in press).