Canadian Forestry: Landscape Mapping of Whole Tree Inherent Wood Properties
Introduction
The forest industry is undergoing a major shift in how it conducts business due mainly from increased competition from other regions of the world. In particular the southern Hemisphere has become a major provider of forest products over the last 2 decades and continue to increase market share in many forest products areas that were traditionally dominated by resource rich countries like Canada. More recently one means of increasing our competitiveness on a global scale is to place value on our resource based on the inherent wood properties of the resource. This is a significant shift from our current way of doing business where we harvest areas and process the logs through a sawmill where the lumber is graded and sold based on the grades. This does not capture the true value of the product, it captures the highest value for commodity lumber.
The Lakehead University Wood Science and Testing Facility (LUWSTF) under the leadership of Dr. Leitch has developed a program on whole tree wood property maps for several tree species in northwestern Ontario with the goal of increasing the value of each tree that is harvested by identifying the main properties along the main stem length and segregating the main stem based on significant changes in properties. The main properties of interest are density, MOE, MOR and Compression parallel to the grain. These properties represent the main mechanical properties for using lumber in structural applications. Once the maps are created for each species and their variability across their natural range (based on eco-site classifications) the information needs to be mapped on a landscape scale to be useful to existing industries as well as potential new industries. In particular we are very interested in attracting new value-adding industries who, by the nature of their products, require more detailed information about the resource for their particular product and therefore need to know where on the landscape the wood quality is the require.
The use of digital mapping has become a standard for forest management and we have used this technology to promote the better utilization of our forest resource. In this study we utilized the Ontario 1996 Forest Resource Inventory (FRI) and the Ontario Digital Elevation Model (DEM).
Mapping
The mapping of the inherent wood properties to landscape maps is displayed using our White Birch study where the inherent wood property maps were created based on eco-sites this species grows on. The maps created were for a value-adding company where the requirements were clear long stems with little to no heartwood color. In our studies on White Birch we discovered the properties were very tightly tied to the eco-sites and in particular to the elevation aspect of the eco-site classification. We found significant differences in the main stem wood properties for trees growing on the low land areas (i.e. low wet areas) compared to the base of a slope, compared to the slope itself and then compared to trees on the top of slope, also referred to as the ridge-top.
With this information maps were then created (click map at top of this post) using the Ontario 1996 Forest Resource Inventory (FRI) and the Ontario Digital Elevation Model (DEM). The DEM was downloaded as a series of points, so the first step was to assemble the points into a surface. Once the surface was created, a query was run that looked for local maxima (aka. the tops of hills). If the query only looked for the highest spots, it would miss minor hills, so the local maxima query made more sense. Next, two composition layers were created by running a query on the FRI layer for stands of White Birch on ridge-top areas that had greater than 50% White Birch composition and a second layer that highlighted ridge-top areas that had greater than 70% White Birch composition. These two resulting layers were then combined so that only forest stands with greater than 50% and 70% that were on top of hills were left. While this type of query is relatively simple, it takes the understanding of geographic influence on wood quality to know what to query. All other stands with less than 50% White Birch were eliminated from the maps.
This produced a map that told the company where on the landscape the White Birch in stands greater than 50% composition and greater than 70% composition were that also were on ridge-tops so the inherent wood properties were what they required. In addition to this an additional layer was overlaid on this map to display the annual Forest Planning Map for the year so the value-adding company was informed who was harvesting in the region and more importantly who was harvesting in the blocks identified in the landscape maps. This allows the value-adding company to work with the primary producer during harvesting of the block to get the White Birch harvested and hauled to roadside for pickup.
Summary
In summary the use of mapping technology for transferring lab measurements of a trees inherent wood properties is a viable means of transferring information to the industry relating to the resource they work with. This should allow industry to better manage their resource and respond more accurately and quickly to market demand. This is particularly important when one considers how diverse the forest is and industry is usually in a situation where there is high demand for a certain grade of lumber so they need to know where that grade is found in quantities on the landscape. In addition these maps will be very powerful to attract investors with new companies to the region when they will know what resource is available and the quality of it, meaning they will know right away if our forests of northern Ontario can meet their requirements and also where on the landscape the quality and quantity is. This will assist in what forest license they will need access to and where they should set up their manufacturing facility.
It is very obvious that the use of mapping technology has increased our ability to better manage our forest resources, however it is not apparent if we can go much further with mapping technology without more inputs relating to wood quality at a landscape scale. The LUWSTF is now utilizing acoustic technology in a project combined with destructive mechanical property testing to correlate acoustic properties to whole tree properties that will allow simple acoustic cruises, similar to a resource inventory cruise, to record whole tree properties on a landscape scale. We are also using ArcGIS to map these changing wood properties across the landscape for a visual representation of properties and how they vary across the landscape.
Written By
Dr. Mathew Leitch, Scott Miller, Alex Bylik
Author for correspondence
