Science > Ecol / Ecos Research > TLHERP

Turkey Lakes Tolerant Hardwoods Ecosystem Research Project (TLHERP)

Location: 60 km north of Sault Ste. Marie, Ontario.
Proponent: Canadian Forest Service, Sault Ste. Marie
Ecozone: Boreal Shield

[ Background | Objectives | Treatments | Studies | Principal Contacts | Partners | Establishment Report | Outputs | FERNS Home Page ] 

Background

The tolerant northern hardwoods are an important forest type in the southern portion of the Boreal Shield Ecozone. Tree species characteristic of this forest type include: yellow birch, hard maple, white spruce, balsam fir, ironwood, and eastern white cedar. Most of this tolerant hardwood forest has been high-graded for quality logs in the past.

The 1000 ha Turkey Lakes Watershed study area was established in 1979 to study the impacts of the long-range transport of air pollutants (LRTAP) on aquatic and terrestrial ecosystems. LRTAP impacts continue to be monitored today and much has been learned about ecosystem function from this extensive, long-term data base. Building on this, a sustainable forest harvesting project beginning in 1997 has been designed for the lower part of the watershed to examine the impacts of harvesting practices on the ecosystem and to calibrate a range of harvesting prescriptions to this important forest type. The forest being studied is a remnant old-growth sugar maple-yellow birch forest on a shallow, Precambrian-derived till soil in rugged topography located in the Algoma Section (L.10) of the Great Lakes St. Lawrence Region of north-central Ontario.

The primary focus of this project is to examine forest community response to stand opening. The availability of, and competition for, light is perhaps the most dominant force in closed canopy forests. Any disturbance process that increases light penetration sets off a chain of events, many of them interrelated, that change structure, composition, function and process within the stand.

Objectives

The forestry practices objectives of the Turkey Lakes Watershed
study include:

1. To quantify the impacts of alternative silvicultural systems and associated
   practices on soils and their long-term productivity in tolerant hardwood forests.
2. To quantify the impacts of alternative silvicultural systems and associated
   practices in tolerant hardwoods on stand function, including recovery of net primary production.
3. To quantify the impacts of alternative silvicultural systems and associated practices in tolerant hardwoods on successional pathways and processes, and on the diversity of plant and animal life.
4. To quantify the impacts of alternative silvicultural systems and associated practices on yield, quality, flora and fauna of headwater streams draining tolerant hardwood forests.
5. To develop environmentally-sustainable silvicultural systems and associated practices applicable to tolerant hardwood that maintain biodiversity, cavity trees and minimize adverse site impacts.

Treatments

Two basic management systems have been proposed for the tolerant hardwood stands in Algoma; the selection system, (an uneven-aged silvicultural system in which trees are removed individually, here and there, over a large area) and the shelterwood system (an even-aged silvicultural system in which, in order to provide a source of seed and/or protection for regeneration, the old crop is removed in two or more successive cuttings).

The system chosen for any stand will depend on silvicultural objectives and quality and composition of the stand. Application of either system, or the less utilized clearcut will result in changes or modification of these systems. Four treatment blocks of varying size, slope and aspect will be established within the watershed. Two blocks will be established on south facing slopes inside the current watershed boundaries, one within and one outside of the basins and two on north facing slopes outside of the watershed. Each of the four treatments will be replicated in each of the blocks.

The core study of the Turkey Lakes Tolerant Hardwood Research Project is a single-factor randomized block field experiment in four blocks comparing alternative silvicultural systems, viz clear-felling, shelterwood, and single-tree selection, plus uncut control, for appropriateness of application within the Algoma Section of the Great Lakes - St. Lawrence Forest Region, and with respect to impacts on soil long-term productivity, stand function including the recovery of net primary production, diversity of plant and animal life, and hydrological and other on- and off-site impacts. Treated areas range in size from 6.0 to 66 ha. Where possible, component studies are co-located to facilitate exchange of information.

Studies

1. 1. Impact of harvesting method on net productivity and recovery of net productivity and nutrient cycling following harvest.
2. 2. Treatment impacts on site nutrient capital and nutrient cycling processes.
3. 3. Treatment impacts on site environmental conditions (measurement of site physical changes in response to stand opening temperature, light, moisture in air, soil microclimate).
4. 4. Impact of harvesting method on vegetation biodiversity and fauna and soil fauna.
5. 5. Impact of harvesting method on soil erosion on steep slopes and methods of minimizing soil erosion.
6. Treatment effects on growth and physiology of understory vegetation (sugar maple
   versus yellow birch, carbon uptake, allocation, water and nutrient status).
7. Treatment impacts on small mammals, birds (including waterfowl) herbs and shrubs
   and soil macrofauna.
8. Simulation or modelling of on-site impacts.
9. Effects of harvesting method on water yield and quality, including sedimentation and
   water temperature, and methods of minimizing impacts.
10. Mobilization of soil elements in relation to harvest method and impacts on water
    quality, and relationship to acid deposition.
11. Simulation or modeling of off-site impacts.

Principal Contacts

Al Cameron, (p) 705-949-9461, alcam@nrcan.gc.ca

Partners

Canadian Forest Service

Ontario Ministry of Natural Resources - S and T Unit, OFRI

Clergue Forest Management

Department of Fisheries and Oceans

Department of the Environment

Forest Engineering Research Institute of Canada

Agawa Forest Products

University of Toronto

University of New Brunswick

University of Waterloo

Establishment Report:

none

Outputs

A long term data record exists for the Turkey Lakes Watershed. Over 200 publications have been written on work carried out at this site to date. The effects of harvesting practices work is expected to add considerably to this knowledge base over the next few years.