USE AND UTILITY OF FOREST BIOMASS: 
Benefits to the Forest, the Community, and Economic Development
by Dr. David DeYoe

This article follows “Global Trends, Local Options: Use and Utility of Forest Biomass” in the February 2006 issue of Canadian Silviculture, which provided a renewed look at the use of forest biomass for green energy, fuels, specialty chemicals, and materials capable of reducing our dependency on fossil fuels and petroleum by-products as part of a new economy, the “bio-economy”. [You can access this article on www.canadiansilviculture.com.]

The bio-economy is composed of technologies and processes that are more environmentally benign, support the principles of the Kyoto Protocol, and create economic opportunities for rural businesses and either add value to existing industry or replace it with new bio-product industries. 

Biomass is defined as all non-fossil organic materials including water and land-based plants (trees, shrubs, herbs, grasses, algae, lichen, moss, etc.) and all waste biomass such as municipal solid waste, municipal sewage and animal manures, forestry and agricultural residues as well as certain types of industrial wastes. Unlike fossil fuels, biomass is renewable and can be replaced within a harvest cycle. Biomass is also considered carbon neutral as its CO2 emissions are offset by the growth of new plants sequestering CO2.
Energy from biomass can be generated directly or by conversion to gas, liquid or solid bio-fuels for use in cogeneration of heat and electricity. Cogeneration using forest biomass is well established in northern Europe, New Zealand, and Australia. Presently, about 40% of electricity generation in Denmark is derived from biomass cogeneration plants using wood waste and straw. In Finland, cogeneration supplies about 10% of electricity using sawdust, forest residues, and pulping liquors. In contrast, bio-energy contributes only about 3-4% of the total energy in Canada and the US.

Benefits of using forest biomass for energy and transportation fuels include the following: 1) it is renewable; 2) it’s increasing affordable; 3) it creates business opportunities and jobs; 4) it reduces global warming; 5) it generates profit from waste; and 6) it provides energy self-sufficiency for industry and rural communities. Given the rising cost of energy, the inefficiencies in energy transmission, and the rising uncertainty in dependable service for remote localities, energy self-sufficiency is a key incentive.

Residual Utilization Benefits to The Forest 
Current practices, which leave harvest residuals in piles or windrows, reduce regeneration sites on cut-overs up to 20%. Leaving harvest residuals dispersed hinders planting and seeding, delays regeneration efficiency and effectiveness, predisposes the site to fire risk, and creates a safety hazard for planters. Residuals can become artificial habitats for animals that feed on seed and seedlings, reduce survival, and may become sources for insects and disease. Burning piles, a common practice, releases combustion gases and particulates. Removing harvest residuals improves worker safety and regeneration and growth of seedlings as well as capturing potential economic benefits.

New market opportunities using biomass can help fund enhanced forest practices. The forest industry has traditionally viewed the woodlands as the cost centre and the mill as the revenue generator. Traditional use of the forest resource has created waste in which full value of the resource is not optimized and, in many cases, tree and stand quality has been eroded by economic harvesting. In the bio-economy, that scenario changes. Value-added outcomes can be derived from: a) residual biomass (energy, fuels and chemicals); b) different plant species possessing high value attributes (pharmaceuticals, functional foods, and crafts); and c) product dependent carbon reservoirs. The value from these outcomes can not only offset operating costs, but also can make the woodlands a bio-economy revenue generator. Future generations will expect a full product cycle bio-economy grounded in the woodlands.

Biomass utilization initiatives do not need to expand resource utilization beyond current allocations. The growing value and need for biomass can be accommodated by good planning. Efficient use of waste material and new or expanded options for biomass utilization and/or production will optimize utilization while alleviating pressure on areas valued for other uses, whether social, ecological, or economic. Figure 1 provides a colour-coded assessment of potential biomass evolution. The black box/solid line represents material from sustainable harvest allocations held constant. The red box/dashed line reflects backlog - materials allocated but not removed or old mill waste piles. The green box/dotted line identifies future stock such as energy plantations, municipal solid waste, and mortality from fire, insects, and disease that may increase as a result of global warming.

A critical requirement in enabling a bio-economy is a comprehensive inventory of the biomass resources and the diverse array of new product opportunities this can create. A biomass inventory must clearly define availability, accessibility, quantity, type, qualitative attributes, transportation networks, delivered costs, etc. to foster integrated use of the forest and stimulate investment in bio-based ventures. 
Regeneration success and economic value can be optimized by utilizing: a) existing slash piles; b) windrow material; c) unmerchantable logs; d) chipping frass; e) low value stands allocated but not harvested; f) trees marked for harvest but left as a result of cutter’s choice; and g) excess residual trees left standing in stands designated for clear cut. This would also free up between 15-20% of the area, or perhaps more, for regeneration and enhancing future stand quality. Allowing cutter’s choice and/or bypassing low value trees in forest stands undermines silvicultural expertise and predisposes stands to a legacy of poor genetic quality. 

Benefits to The Community 
Adaptation and mitigation strategies using the forest resource to address climate change can provide significant benefit to communities. Thinning programs in the US help mitigate against stress-induced effects of climate change (minimizing competition for water and nutrients by using vegetation management practices in plantations), and help avoid drought-related stresses and fire, insect, and disease risk while utilizing the biomass for energy. Sustainable bio-practices create community jobs.

Biomass from intensive silviculture is commonly used in Europe for heat and power production (co-generation). These strategies for biomass use are integral to resilient systems for energy and water security in rural areas. An energy self-sufficient north could be, and should be, the provider for the power-hungry south, with financial benefits flowing back into the rural communities to foster business development. 

Benefits to Economic Development 
Longer-term planning will optimize use of the forest resource. Figure 1 provides a view of how biomass-based residual or waste materials can be planned over time. This approach allows communities or companies to address impacts associated with global warming while integrating biomass into the mix of renewable resource options (hydroelectric, geothermal, solar, wind, etc.), which can enable the move toward energy self-sufficiency. Biomass is a major piece of the renewable energy and fuels picture for Canada - it is not currently receiving the attention it deserves given the benefits it can provide. For example, in southeastern Ontario there are approximately 900,000 ha of abandoned farm and forestlands. Production rates for Ontario willow clones developed at Syracuse University are 10 bone-dry tonnes/ha/yr on a 3-year rotation. Using only 60% of this land base would produce 1,800,000 bone-dry tonnes annually on a 3-year cycle, or about 300 MW of electricity and 600 MW of heat. This is enough to serve 30 communities, each with a population of 2,500 to 4,000 people…not an insignificant contribution.

Canada and the provinces can address emission reductions inherent in the Kyoto Protocol by using biomass fuel to displace a fossil fuel source (petroleum, natural gas or coal). Some developing technologies take this a step further by recycling and using the CO2 that would normally have been emitted in fossil fuel utilization. Further, just like wood and paper products, some products derived from biomass can capture carbon for long periods of time, particularly biopolymers or platform chemicals used in everyday products. 
Besides forest and mill waste, areas devastated by mortality due to fire, insects, disease, and wind throw are excellent candidates for bio-energy projects. The volume loss due to the Mountain Pine Beetle infestation, for example, is now 6 million m³ or about 3 million bone-dry tonnes. Entrepreneurs are currently capitalizing on the market demand for biomass in Europe to drive biomass for energy projects. Although some fear that the forest-based industry in this area may crash in 15 years, with innovative planning natural forests could be co-mingled with energy and bio-fuel plantations now. This would help sustain the boom and avoid the bust, although the products that support communities and business may be very different.

Challenges to Master
It is critical to avoid site degradation activity by diversion from best practices in accessing forest biomass. The removal of slash piles or windrows, standing residual, cull and frass, and unmerchantable logs will increase planting spots. The utilization of standing residual from scheduled clear cuts would be taken at harvest instead of being left to devalue the stand, and stands allocated but not harvested would likely be harvested due to new product options. There are numerous options for biomass utilization that contravene policies or guidelines for maintenance of long-term site productivity.

Over a typical Canadian forest rotation of 60-80 years, annual inputs of nutrients and organic matter occur in the form of fine root and mycorrhizal turnover, small root loss, loss of leaf material and small to medium sized branches, and isolated wind throw. These help maintain the productive character of the soil and site. These annual inputs do not include atmospheric deposition of nitrogen or any of a number of random natural disturbances (fire, insect and disease mortality, severe blow down, etc.) that occur regularly in the forest system. The harvest actually represents only a small sliver in a forest’s rotational cycle. Table 1 provides a conceptual view of nutrient retention on a site over a 60-year rotation, by different plant components. The organic matter retention is represented by the components of the tree not removed, e.g. percentage retained or consumed on the site during the 60-year period.

Full tree harvesting studies find no detrimental effects to longer-term productivity on most forest sites. However, more intensive extraction of round wood and residual over shorter rotations may require the use of soil amendments - a common practice in jurisdictions using rotations between 7 and 25 years, e.g. Finland, Sweden, Southeast US, and Brazil.

Although we tend to discount the importance of the below-ground contribution to organic matter and nutrient inputs, it is significant - annually and over the rotation. For sites that are cold, wet, and nutrient-poor (boreal and subalpine zones), trees allocate a large proportion of their total carbon for root structure and function below ground. This provides fine root infrastructure to sequester nutrients (Figure 2), and can amount to 50-70% of the total annual biomass distribution. Even on warm, moist, nutrient-rich sites the below-ground annual allocation is 35-50%. This organic matter, and the associated nutrients, remains on site, as does large, woody debris occurring from natural disturbances. Interestingly, below-ground distribution is even greater for herbs and grasses, which can allocate 80-90% of total annual carbon below ground - one reason why the grasses and herbs are such tenacious competitors for water and nutrients in young plantations. This below-ground contribution accounts for a substantive quantity of organic matter and nutritional capital retention on site at harvest and beyond. 

Future Directions
The use of forest and agricultural biomass goes far beyond energy. Energy, and perhaps certain enhanced fuels (ethanol and green diesel), will comprise the first wave. However, as the technology to convert biomass develops and becomes integrated with industries focusing on platform chemicals, polymers, and enhanced fuels, a whole new wave of renewable products from biomass will evolve. This is the market that is catching the attention of entrepreneurs and the innovators and early adopters of big industry. Whether a farmer or a forester, the opportunities to capitalize on this market are significant. The key to rural revitalization will be retaining as much of the value chain in the rural area as possible, and to develop business models for rural ownership.

New directions are all about positioning companies and communities to capture the opportunities inherent in global trends. Although the implications of most global trends appear to paint a rather bleak picture of what lies ahead, the reality is these trends unveil opportunities with significant economic, social, and/or environmental benefits to rural areas. The trick is to identify trends for which there exists a “silver lining”, and then develop approaches to capture the opportunities.

Dr. David DeYoe is President of Bio-Trend Systems Incorporated. He was General Manager of the Ontario Forest Research Institute between 1992 and 2004 and a Reforestation Biologist on the Faculty of Oregon State University from 1979 to 1986. He has had a long career in the silviculture industry.