Nancy Luckai

Challenges in the Application of Existing Process-Based Models to Predict the Effect of Climate Change on C Pools in Forest Ecosystems

Process-based models used to investigate forest ecosystem response to climate change were not necessarily developed to include the effect of carbon dioxide (CO2) and temperature increases on physiological processes. Simulation of the impacts of climate change with such models may lead to questionable predictions. It is generally believed that significant shifts in the performance of black spruce (Picea mariana [Mill] B.S.P.) will occur under climate change. This species, which accounts for 64% of Ontarios coniferous growing stock and 80% of the annual allowable cut, represents important economic activity throughout the boreal forest region. Forest management planning requires relatively accurate productivity estimates. Thus, it is imperative to ensure that process-based models realistically predict the effect of climate change. In this study, CENTURY and FOREST-BGC models were calibrated for a productive, upland black spruce stand in northwestern Ontario. Even though both models predicted similar relative outcomes after 100 years of climate change, they disagreed on the impacts of temperature in combination with an increase in CO2. Also, absolute amounts of carbon sequestered varied with climate change scenarios. Comparison of both models indicated that the representation of critical processes in these two forest ecosystem models is incomplete. For instance, the interactive effects of CO2 and temperature increases on physiological processes at stand and soil levels are not well documented nor are they easily identifiable in the models. Their incorporation into models is therefore problematic. Practitioners must consequently be wary of assumptions about the inclusion of critical processes in models.

An analytical framework to assist decision makers in the use of forest ecosystem model predictions

The predictions from most forest ecosystem models originate from deterministic simulations. However, few evaluation exercises for model outputs are performed by either model developers or users. This issue has important consequences for decision makers using these models to develop natural resource management policies, as they cannot evaluate the extent to which predictions stemming from the simulation of alternative management scenarios may result in significant environmental or economic differences. Various numerical methods, such as sensitivity/uncertainty analyses, or bootstrap methods, may be used to evaluate models and the errors associated with their outputs. However, the application of each of these methods carries unique challenges which decision makers do not necessarily understand; guidance is required when interpreting the output generated from each model. This paper proposes a decision flow chart in the form of an analytical framework to help decision makers apply, in an orderly fashion, different steps involved in examining the model outputs. The analytical framework is discussed with regard to the definition of problems and objectives and includes the following topics: model selection, identification of alternatives, modelling tasks and selecting alternatives for developing policy or implementing management scenarios. Its application is illustrated using an on-going exercise in developing silvicultural guidelines for a forest management enterprise in Ontario, Canada.

Life cycle cost and economic assessment of biochar-based bioenergy production and biochar land application in Northwestern Ontario, Canada

BackgroundReplacement of fossil fuel based energy with biochar-based bioenergy production can help reduce greenhouse gas emissions while mitigating the adverse impacts of climate change and global warming. However, the production of biochar-based bioenergy depends on a sustainable supply of biomass. Although, Northwestern Ontario has a rich and sustainable supply of woody biomass, a comprehensive life cycle cost and economic assessment of biochar-based bioenergy production technology has not been done so far in the region.MethodsIn this paper, we conducted a thorough life cycle cost assessment (LCCA) of biochar-based bioenergy production and its land application under four different scenarios: 1) biochar production with low feedstock availability; 2) biochar production with high feedstock availability; 3) biochar production with low feedstock availability and its land application; and 4) biochar production with high feedstock availability and its land application- using SimaPro®, EIOLCA® software and spreadsheet modeling. Based on the LCCA results, we further conducted an economic assessment for the break-even and viability of this technology over the project period.ResultsIt was found that the economic viability of biochar-based bioenergy production system within the life cycle analysis system boundary based on study assumptions is directly dependent on costs of pyrolysis, feedstock processing (drying, grinding and pelletization) and collection on site and the value of total carbon offset provided by the system. Sensitivity analysis of transportation distance and different values of C offset showed that the system is profitable in case of high biomass availability within 200 km and when the cost of carbon sequestration exceeds CAD

Biochar-based bioenergy and its environmental impact in northwestern Ontario Canada: a review.

60 per tonne of equivalent carbon (CO2e).ConclusionsBiochar-based bioenergy system is economically viable when life cycle costs and environmental assumptions are accounted for. This study provides a medium scale slow-pyrolysis plant scenario and we recommend similar experiments with large-scale plants in order to implement the technology at industrial scale.

The Influence of Coarse Woody Debris on Soil Carbon and Nutrient Pools 15 Years after Clearcut Harvesting in Black Spruce—Dominated Stands in Northwestern Ontario, Canada

Biochar is normally produced as a by-product of bioenergy. However, if biochar is produced as a co-product with bioenergy from sustainably managed forests and used for soil amendment, it could provide a carbon neutral or even carbon negative solution for current environmental degradation problems. In this paper, we present a comprehensive review of biochar production as a co-product of bioenergy and its implications. We focus on biochar production with reference to biomass availability and sustainability and on biochar utilization for its soil amendment and greenhouse gas emissions reduction properties. Past studies confirm that northwestern Ontario has a sustainable and sufficient supply of biomass feedstock that can be used to produce bioenergy, with biochar as a co-product that can replace fossil fuel consumption, increase soil productivity and sequester carbon in the long run. For the next step, we recommend that comprehensive life cycle assessment of biochar-based bioenergy production, from raw material collection to biochar application, with an extensive economic assessment is necessary for making this technology commercially viable in northwestern Ontario.

Coarse Woody Debris Dynamics Following Biomass Harvesting: Tracking Carbon and Nitrogen Patterns During Early Stand Development in Upland Black Spruce Ecosystems

Abstract: This study was designed as a log-scale examination of the influence that decomposing coarse woody debris (CWD in situ for 15 y following harvesting) had on soil carbon and nutrient levels. The study included 4 study sites representing 2 soil types: loamy tills versus sandy outwashes. The mature, fire-origin mixed conifer stands occupying these sites were clearcut harvested in 1994. In 2009, estimates of both total soil carbon and total and available nutrient pools were compared in locations under versus away from CWD. The presence of decaying CWD (now decay classes 3–4) significantly increased soil carbon (+85 %) and nitrogen (+49 %) pools. Estimates of inorganic N from a fresh soil 2M KCL extraction, however, were lower underneath the logs, suggesting that N immobilization is occurring as part of the decomposition process. In contrast, the presence of CWD had no significant effect on P, K, Ca, or Mg soil pools. Although there were marked differences in soil nutrient pools between the 2 soil types, the patterns associated with the presence of CWD were largely the same, and suggest that the influence of CWD does not extend beyond the bounds of the CWD. The results suggest that it will be important that biomass harvesting guidelines consider and include CWD retention levels to ensure that this important ecosystem component, with its associated functions (e.g., soil fertility, nutrient cycling), is maintained in harvested landscapes.

From coal to wood thermoelectric energy production: a review and discussion of potential socio-economic impacts with implications for Northwestern Ontario, Canada

Abstract Coarse woody debris (CWD) in the boreal ecosystem has been hypothesized to play an important nutritional role following stand-replacing disturbances such as fire or harvest. Sites with shallow soil over bedrock, or those with coarse-textured soils, can be especially susceptible to overstory removal because low carbon and nutrient pools may limit stand productivity in subsequent rotations. On these site types, CWD can provide essential nutrition to the developing second growth stand, prior to internal cycling processes stabilizing at crown closure (15 years to 20 years after stand initiation) through slow and steady decomposition. The current study sites were established in 1994 and in 2008 (14 years following harvesting) and were approaching crown closure. The experimental harvest areas were designed to document carbon loss and nutrient fluxes after the application of four levels of biomass removal from mature black spruce forested stands in northwestern Ontario, Canada. Two soil types (fresh, loamy : dry, sandy), with stand replicates (blocks), were selected to test whether residual CWD represents a source or sink for nutrients, and if the decay pattern varied depending on soil type. Measurement/sampling of CWD was done immediately after the harvest treatments were applied, and again in year 4 and year 14. The biomass removal treatment with the greatest carbon loss and fastest CWD decay rate had the highest initial mass of CWD, indicating possible synergistic decay dynamics. Nitrogen concentration in the CWD continued to increase from the initial measurements to year 14 (from 900 ppm to 2400 ppm), but was largely a function of increasing carbon loss. When converted to N content in CWD (kg ha-1), however, nitrogen exhibited an initial upward trend (i.e., immobilization) through years 1to 4 (from 50 kg ha-1 up to 80 kg ha-1) and a subsequent release in years 5 to 14 (from 80 kg ha-1down to 27 kg ha-1). This trend was more apparent on the dry, sandy sites where N content peaked at almost 100 kg ha-1 at year 4, but then reduced to 26 kg ha-1 by year 14. We compared the average loss of N from CWD in years 4 to 14 (5.3 kg ha-1 yr-1) to the total soil inorganic N pool (based on a fresh K2SO4 extraction), and found that the N loss from CWD represented a substantive portion (80%) of the available N pool, particularly on the dry, sandy sites. After an initial peak in year 4, black spruce foliar N decreased significantly (p<.0001) through to year 10 but began to rebound by year 15. This increase, presumably, was in part the result of the documented release of N from CWD. These results suggest that CWD, although a small contributor to the total N pool, makes a substantial contribution to the relatively small available N pool, especially on dry, sandy soils. The trend of initial N immobilization and subsequent release shows CWD may also serve to buffer the initial leaching of nutrients from the site following harvesting and provide an available source of N to the regenerating stand prior to crown closure.

Within-Crown Distribution Patterns of White Spruce in Pure Composition and in Mixture with Trembling Aspen

The province of Ontario in Canada is the first North American jurisdiction withlegislation in place to eliminate coal-fired thermoelectric production by theend of 2014. Ontario Power Generation (OPG) operates coal-fired stations inOntario, with Atikokan Generating Station being the only facility slated toswitch to 100% woody biomass. It is anticipated that this coal phase out policywill have socio-economic impacts. Because of these anticipated changes, in thispaper, we review the current state of peer-reviewed literature relating to threeburning scenarios (biomass, coal and co-firing) in order to explore theknowledge gaps with regard to socio-economic impacts and identify research needswhich should elucidate the anticipated changes on a community level. We reviewedover 150 sources, which included peer-reviewed articles and non-peer-reviewedgrey literature such as government documents, non-governmental organizationreports and news publications. We found very few peer-reviewed articles relatedto Canadian studies (even fewer for Ontario) which look at woody biomass burningfor thermoelectric production. We identify a number of socio-economic impactassessment tools readily available and present potential criteria required inselecting an appropriate tool for the Ontario context. For any tool to providemeaningful results, we propose that appropriate and robust local data must becollected and analyzed.

A practical approach for assessing the sensitivity of the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3)

Abstract: The purpose of this investigation was to examine the effects of species composition and crown section on withincrown foliage distribution and the relationship of basal area growth rate to amount of foliage on young white spruce (Picea glauca) growing in pure composition and in mixture with trembling aspen (Populus tremuloides). Branch and needle biomass, projected leaf area, specific leaf area, and ratio of needle biomass to branch biomass, along with several whole-tree metrics, including height and diameter at breast height (1.3 m), were measured on thirteen 20-y-old white spruce trees, 7 from pure composition and 6 from mixed composition. While there was no effect of composition on whole-tree differences among subject trees, within-crown distribution of branch and foliage amount and morphology and concentration of foliage were significantly affected by both composition (mixed and pure) and crown section (lower, mid, upper). There was a positive relationship between periodic annual basal area increment and foliage amount (biomass and projected area) on subject white spruce trees that did not differ between trees in pure and mixed compositions. Despite the significant effect of species composition on the vertical within-crown distribution of foliage and branch amount and foliage morphology, similar changes in total foliage biomass and area had similar effects on periodic annual increment of basal area regardless of composition.