By Jean-Luc Bernier
Feb. 3, 2015 - How would you feel about saving $1.57/m³ on your delivered wood costs? How about having access to better-defined cutblock boundary lines, a fully optimized road network or dealing with reduced mill-yard inventory? Sounds good, right?
These appear to be just a few of the benefits related to the use of Enhanced Forest Inventory (EFI), yet not many companies seem interested in investing in EFI-allowing technologies such as aerial LiDAR. A formidable laser-based remote sensing technology, LiDAR measures distance by sending thousands of pulses of light with a laser from an aircraft and analyzing what reflects back (http://tinyurl.com/pe8ayfh).
Only a handful of cases of documented cost/benefit analyses actually exist to guide the decision-making process when choosing from all the available technologies designed to significantly improve inventory knowledge. Hence, EFI technologies still remain a marginal practice among forestry technology and service providers. Confident in its capacity to transform the forest sector, FPInnovations set out to find out what EFI is really about.
Partnering with Tembec and the Ontario Ministry of Natural Resources (OMNR) allowed researchers from FPInnovations’ Value Maximisation research program to evaluate the monetary impact of EFI on forest operations and primary wood products manufacturing. The results have turned out convincingly in favour of EFI: great return on investment, better knowledge of forest inventory, smaller road network, efficient harvesting operations and increased forest machine productivity. With smaller mill yard inventories of greater value, sawing cost can be reduced and lumber value increased, mostly due to the increased size of timber. The big question now is: why haven’t more companies picked up on the new generation of technologies designed to help them be more profitable?
Innovation in the field of forest inventory is no science-fiction. Today, there are very real cost-competitive technologies that allow accurate data gathering about forest stand attributes. Using these tools, foresters can truly maximize the value of forest products by lowering production costs and increasing the value of processed forest products. However, one obvious barrier in justifying the investment relates to the complexity of validating the benefits. Testing EFI processes and technologies involves getting access to data collected along the entire forest sector value chain. Since FPInnovations is all about value chain integration, researchers were able to gather the relevant information to compare the volumes as well as the wood net value resulting from two inventory data sets (traditional vs LiDAR-EFI).
Very promising advances
In addition to being costly, traditional forest inventories are difficult to update. In terms of stands, they produce a lack of volume precision in the area of 20 to 40 per cent, often making it necessary to obtain additional data in order to make informed decisions. There is a lack of data on variability of dendrometric characteristics within forest stands which limits harvest-planning decisions.
Accuracy of inventory data is very important since many decisions and actions are taken along the wood value chain based primarily on forestry inventory data. Inaccuracies result in costs for forest stakeholders at various levels and also mean that landowners run the risk of not maximizing benefits or value from resources (wood fibre, habitat, tourism, etc.).
One of the challenges met by the Enhanced Forest Inventory process is to provide foresters with precise and detailed information, both on a large and operational scale for each block to be processed. The arrival of aerial LiDAR (Light Detection and Ranging) has allowed foresters to meet this challenge head on. The quality of the information can now exceed expectations and an entire forest can now be inventoried at resolution as high as 400 m2. Furthermore, major steps have been taken toward posting the internal attributes of the wood’s fibre on forest maps using the EvaluTree program (a joint collaboration by FPInnovations and the University of Northern British Columbia).
Aerial LiDAR generates measurements in 3D space that provide a good description of the forest canopy and stand structure, which can be used to accurately predict tree crown dimensions, height, volume canopy density and biomass. Measurements made at the ground surface can be used to accurately map waterways (creeks, bogs, rivers, lakes) and topography across an entire forest (figure 1). While limited plot data are needed to calibrate LiDAR predictions, field sampling is no longer required for stand-, block-, and forest-level estimates. The wall-to-wall precision provided by LiDAR leads to better growth projections, product recovery models, taper models, biomass models, as well as silvicultural optimization and operational planning.
Maps created with LiDAR also provide valuable information for road construction by identifying optimized log extraction routes. Block contours are also better defined, impacting the precision of performance calculations (m³/stem/ha). Furthermore, a more detailed knowledge of forest structure makes silvicultural prescriptions easier. Combined with FPInterface software, LiDAR obtained cartographic and georeferenced data allow better prediction of operational costs for harvesting, transportation, road construction and silviculture.
Field testing EFI technology
By comparing two inventory data sets (traditional versus LiDAR-EFI), FPInnovations researchers were able to estimate costs and benefits of each method. To ensure the accuracy of LiDAR inventories, actual volumes harvested (scaled) were compared to yield estimates derived from the traditional inventory (OMNR provincial inventory) and to the LiDAR-enhanced inventory. The study focused on 14 cutblocks from Tembec’s 2009 forest management plan. Ultimately, in this study, the cost of $0.10/m³ for the LiDAR-EFI was largely offset by reduced wood costs. FPInnovations observed a net gain of $1.57/m³ when compared with the actual harvest as planned from traditional forest inventory.
Watch FPInnovations’ video on EFI: https://www.youtube.com/watch?v=-VmAy6rxt-U
For more information, please contact Francis Charette at 514-782-4608 or firstname.lastname@example.org. The FPInnovations report “Better planning with LiDAR-enhanced forest inventory” can be found here: http://tinyurl.com/p2yzcp7.