Goals
Background
Location
Contact

The Pockwock-Bowater Watershed Study is an on-the-ground, forestry-based, ecosystem research project. The primary focus is to measure the response of stream water (quality and quantity) when forest harvesting occurs and SMZ are maintained. The study also examines the compounding effect of acid precipitation on nutrient cycling in the system.

The Project concept was developed through collaboration between Environment Canada, Ecosystem Science (EC), and Nova Scotia Dept. of Natural Resources, Forestry Division (NSDNR). NSDNR was developing regulations to require special management zones along watercourses and EC had been conducting a research project in association with the Fundy Model Forest on the effectiveness of riparian zones at Hayward Brook, Southern New Brunswick . The intent was to transfer what was learned at Hayward Brook, as well as the research design, to a site in Nova Scotia . The goal was to gain a broader understanding of SMZ function.

The study is located in central Nova Scotia near Halifax on the western limits of the NFA region. Through the Partnership of the NFA, two adjoining watersheds were located for the study. One is located on lands owned by Bowater Mersey and the other is on Provincial Crown managed in cooperation with NSDNR, Halifax Regional Water Commission and Elmsdale Lumber. Special management zones are being applied to any watercourse that has a flow channel of 50 cm in width or greater. Based on this criterion, eight watercourses and their sub-watersheds were identified. Four are located within the Pockwock Lake watershed and four within the Big Indian Lake watershed. The study will duplicate itself on each of the two main watersheds. Each of the eight sub-watersheds has been delineated and mapped in a GIS (geographic information system) format and the sampling/monitoring sites established.

One sub-watershed in each area will not be harvested. The other three sub-watersheds in each area will have approximately 25-40 percent of the timber harvested leaving a special management zone along each watercourse. One sub-watershed will maintain a 20-metre SMZ with no harvesting in the SMZ. Another sub-watershed will have a 20-metre SMZ in combination with a selection harvest within the SMZ. The final watershed will have a 30-metre SMZ in combination with a selection harvest within the SMZ.

The results of the study will provide guidance to landowners and forest managers regarding forest harvesting planning and layout. It examines the issue from two perspectives; the function of SMZ, and the amount of a watershed harvested. In combination with lake water monitoring, the results will also be incorporated into forest management plans for Pockwock Lake watershed, which is the primary drinking water supply for Halifax .

• Establish a multi-level research project, based on a "partnership" approach.
• Provide data to managers of drinking water supplies on the quality and quantity of runoff from small streams after harvesting, and quantity and the quality of precipitation entering the protected watershed.
• To refine models used to assess cut block size and layout to minimize environmental effects.
• To provide guidelines for redesign and maintenance of special management zones for a variety of purposes including the planning of trails.
• To determine the optimum size and structure of Special management Zones.
• To promote and facilitate cooperative research among a variety of partners.
• To communicate results to decision makers and land managers.

Forest management today encompasses more than the trees alone. The recognition of the benefits of an ecosystem approach to managing forests combined with concern about how forestry interacts with the natural environment has highlighted the need for a science-based approach to best forest management and harvesting practices.

When managing the forest, it is important to consider how the forest and water resources interact. Poor forest management practices can change and harm water quality and therefore fish habitat. Leaving special management zones (SMZ) adjacent to water courses is one forest management practice intended to lessen harvesting's impact on water. SMZ are the area of the forest adjacent to a watercourse 50 cm or greater in width also known as buffer strips. In Nova Scotia the width of an SMZ as defined by regulations is at minimum 20m and increases if the average slope of the land is greater than 20 per cent.

Specifically, SMZ are intended to minimize the impact of forest management on adjacent water courses in terms of water quality and quantity. By minimizing forest management's impact on water quality and quantity the potential impact on habitat for wildlife, fish, and aquatic insects is also reduced. Public water supplies, such as the Pockwock Watershed, also have a particular concern in regard to how forest management and the water resource interact.

An SMZ's effectiveness may vary depending on its width, the nature of soils, vegetation coverage and stability, hydrology, topography and other localized factors such as precipitation levels. To make sure an SMZ is effective, it is important to understand the factors which can reduce its effectiveness and what can be done to compensate. This understanding can best be gained through field tests involving extensive monitoring and analysis. Research of this type requires a broad base of expertise and research sites as well as other resources, not all of which are likely to exist in one organization or agency. In the Pockwock-Bowater Watershed Study this research has been undertaken through a multi-agency partnership.

The study is located in central Nova Scotia near Halifax on the western limits of the Nova Forest Allience, (NFA) region. The Pockwock Bowater Watershed Study is being carried out on two main land bases. One is located on lands owned by Bowater Mersey Co. Ltd. The other adjacent site is located on Provincial Crown land managed in cooperation with Nova Scotia Department of Natural Resources (NSDNR), Halifax Regional Water Commission and Elmsdale Lumber.

Within each of these sites there are four sub-watershed areas for a total of eight sub-watersheds throughout the project. Each sub-watershed is situated around a stream and is monitored for stream water quality and quantity, subsurface water chemistry (soil lysimeters) and subsurface water flow and quality (shallow wells).

The study and treatment to the sub-watersheds is mimicked on the two main land bases. On each land base one of the four sub-watersheds acts as a control and no harvesting occurs in that area. The other three sub-watershed in each area will have approximately 25-40 percent of the timber harvested leaving a special management zone along each watercourse. One sub-watershed will maintain a 20 metre special management zone (SMZ) with no harvesting in the SMZ. Another sub-watershed will have a 20 metre SMZ in combination with a selection harvest within the SMZ. The final watershed will have a 30 metre SMZ in combination with a selection harvest within the SMZ.

If you have any questions or comments about the Pockwock-Bowater Watershed Study please contact us.

pockproj@gov.ns.ca