Forests, Silviculture & Climate Change

The Effects of Forest Management on Carbon Storage in Ontario’s Forests
Stephen J. Colombo et al., 2005. Ontario Ministry of Natural Resources, 139 pp. “This report examines how forest management can affect the carbon (C) balance of Ontario’s forests. Ten forest management activities organized in four themes were examined: stand establishment (site preparation, planting, and vegetation management), growth enhancement (thinning, fertilization, and genetic improvement), forest protection (from forest fires, and insect and disease infestations), and harvesting (controlling the area occupied by
roads, skid trails and landings, and reducing the area disturbed by harvesting).

Climate Change Resilience and Carbon Storage Silvicultural Prescriptions for the Acadian Forest Region (PDF of Silvicuture Decision Key); AND Workshop 1 – Presentation of Climate Change Adaptive Silviculture Prescriptions v.1 – Gareth Davies (YOUTUBE VIDEO of presentation, 46 min); also available, a Preview (1 min).
Prepared by Gareth Davies FT, CLP, Forest Ecologist, Silviculturalist with input from Megan de Graaf, MScF, Community Forests International Version 1.0 2019. “The New Brunswick Federation of Woodlot Owners (NBFWO) is working to build the capacity to adapt to changing environmental conditions on private woodlots. This three year project (Fall 2018 – Fall 2021) is supported by funding from Natural Resource Canada’s Climate Change Adaptation Program, GNB’s Environmental Trust Fund, as well as through work by our project partners, Community Forests International, University of New Brunswick and the NB Department of Natural Resources and Energy Development.”
Also view: – Definition of Terms v.1.0
Appendix B – Supporting Information v.1.0

Does management improve the carbon balance of forestry?
Timo Pukkala, Forestry Volume 90, Issue 1, 1 January 2017, Pages 125–135 Abstract
The long-term carbon balance (CB) of unmanaged forest was compared to the CBs of management scenarios which included cuttings. The calculations were done for a typical forest holding representing mineral soil sites in Central Finland. CB was calculated for twenty-one 10-year periods. Three carbon stores and sub-balances were included in the analysis: (1) below- and above-ground biomass of living trees; (2) forest soil (dead organic matter); and (3) wood-based products. Substitution effects and the releases from harvesting, transporting and manufacturing were included in the CB of products. The no-cutting scenario had the best CB for 120–130 years, after which the cutting scenarios were better. In the no-cutting scenario, the CB of living biomass turned zero after 150 years and the CB of forest soils was still positive after 200 years. At the end of the 210-year simulation period the CB of the unmanaged forest was 0.09 Mg C ha−1a−1 suggesting that old-growth forest is a weak carbon sink. Heavy selective cutting in a mature forest removing half of growing stock volume had a negative influence on the CB of forestry for three decades, after which the balance was better than without cutting. Since the negative and positive effects of cutting have different durations, conclusions about the effect of cutting depend on the length of the time horizon. Because the net effect of cutting is negative in the short term, a short-sighted analysis leads to no-cutting decision when carbon sequestration is maximized, which is a wrong decision in a longer term. When harvested volume was equal to volume increment, the carbon stocks stabilized to 65 Mg C ha−1 for living biomass, 80 Mg C ha−1 for soil and 18 Mg C ha−1 for products.

Another version: Carbon forestry is surprising by Timo Pukkala in Forest Ecosystems 5, 11 (2018). The conclusion: “Letting many mature trees to die was a better strategy than harvesting them when the aim was to maximize the long-term carbon balance of boreal Fennoscandian forest. The reason for this conclusion was that large dead trees are better carbon stores than harvested trees. To alter this outcome, a higher proportion of harvested trees should be used for products in which carbon is stored for long time.”

Also view: At what carbon price forest cutting should stop, Timo Pukkala, 2020 Journal of Forestry Research

Enhanced carbon storage through management for old-growth characteristics in northern hardwood-conifer forests
SARAH E. FORD AND WILLIAM S. KEETON Ecosphere April 2017 ❖ Volume 8(4): 1-20 ” We are testing the hypothesis that aboveground biomass development (carbon storage) is greater in structural complexity enhancement (SCE) treatments when compared to conventional uneven-aged treatments. Structural complexity enhancement treatments were compared against selection systems (single-tree and group) modified to retain elevated structure. Manipulations and controls were replicated across 2-ha treatment units at two study areas in Vermont, United States. Data on aboveground biomass pools (live trees, standing dead, and downed wood) were collected pre- and post-treatment, then again a decade later. ..From Conclusions Adaptive silvicultural practices promoting multiple co-benefits, for instance, by integrating carbon with production of harvestable commodities, can contribute to efforts to dampen the intensity of future climate change while maintaining resilient ecosystems (Millar et al. 2007). Prescriptions that enhance in situ forest biomass and thus carbon storage offer one such alternative (Ducey et al. 2013). U.S. forests currently offset approximately 16% of the nation’s anthropogenic CO2 emissions, but this has the potential to decline as a result of land-use conversion and lack of management (EPA 2012, Joyce et al. 2014). While passive or low-intensity management options have been found to yield the greatest carbon storage benefit, assuming no inclusion of substitution effects (Nunery and Keeton 2010) or elevated disturbance risks (Hurteau et al. 2016), we suggest the consideration of SCE to enhance carbon storage. Multiple studies have explored co-benefits provided by management for or retention of elements of stand structural complexity, including residual large living and dead trees, horizontal variability, and downed CWM (Angers et al. 2005, Schwartz et al. 2005, Dyer et al. 2010, Gronewold et al. 2012, Chen et al. 2015). Silvicultural treatments can effectively integrate both carbon and late-successional biodiversity objectives through SCE based on this study and previous research (e.g., Dove and Keeton 2015). Remaining cognizant of the potential for old-growth compositional and structural baselines to shift over time and space with global change‹climate impacts on forest growth and disturbance regimes, altered species ranges, and the effects of invasive species‹will be important for adaptive management for late-successional functions such as carbon storage.

Forest carbon storage in the northeastern United States: Net effects of harvesting frequency, post-harvest retention, and wood products
Nunery, J., and W. S. Keeton. 2010. Forest Ecology and Management 259:1363–1375. Abstract: Temperate forests are an important carbon sink, yet there is debate regarding the net effect of forest management practices on carbon storage… Our research describes (1) the impact of harvesting frequency and proportion of post-harvest structural retention on carbon storage in northern hardwood-conifer forests, and (2) tests the significance of including harvested wood products in carbon accounting at the stand scale. We stratified Forest Inventory and Analysis (FIA) plots to control for environmental, forest structural and compositional variables, resulting in 32 FIA plots distributed throughout the northeastern U.S. We used the USDA Forest Service’s Forest Vegetation Simulator to project stand development over a 160 year period under nine different forest management scenarios. Simulated treatments represented a gradient of increasing structural retention and decreasing harvesting frequencies, including a  no harvest scenario. The simulations incorporated carbon flux between aboveground forest biomass (dead and live pools) and harvested wood products. Mean carbon storage over the simulation period was calculated for each silvicultural scenario. We investigated tradeoffs among scenarios using a factorial treatment design and two-way ANOVA. Mean carbon sequestration was significantly (± = 0.05) greater for  no management compared to any of the active management scenarios. Of the harvest treatments, those favoring high levels of structural retention and decreased harvesting frequency stored the greatest amounts of carbon. Classification and regression tree analysis showed that management scenario was the strongest predictor of total carbon storage, though site-specific variables were important secondary predictors. In order to isolate the effect of in situ forest carbon storage and harvested wood products, we did not include the emissions benefits associated with substituting wood fiber for other construction materials or energy sources. Modeling results from this study show that harvesting frequency and structural retention significantly affect mean carbon storage. Our results illustrate the importance of both post-harvest forest structure and harvesting frequency in carbon storage, and are valuable to land owners interested in managing forests for carbon sequestration.

How much can forests fight climate change?
Gabriel Popkin in Nature (News feature) 15 JANUARY 2019 Nature 565, 280-282 “Trees are supposed to slow global warming, but growing evidence suggests they might not always be climate saviours.” A good overview of some very complex science.

British Columbia Ministry of Forests, Lands and Natural Resource Operations Forest Carbon Strategy 2016-2020
B.C. Gov., 7pp No Date. presumably circa 2016
“Forest carbon management strategies to increase carbon sinks or reduce emissions fall into six broad
1. Increase (or maintain) forest area;
2. Increase stand-level carbon density;
3. Reduce emissions associated with forestry operations;
4. Increase landscape-level carbon density;
5. Increase the proportion of harvested wood that is used for long-lived products; and,
6. Create forests that are more resilient to changes in climate suitability, pathogens, invasive species, drought, and wildfire”

Canada’s forests haven’t absorbed more carbon than they’ve released since 2001
Sarah Lawrynuik in The Narwhal, May 7, 2019 “Up until the last two decades, our forests had the power to sequester in excess of a hundred megatonnes of carbon dioxide equivalent each year”

Forest Management for Carbon Sequestration and Climate Adaptation
Todd A Ontl et al., 2020. Journal of Forestry, Volume 118, Issue 1, January 2020, Pages 86–101 “The importance of forests for sequestering carbon has created widespread interest among land managers for identifying actions that maintain or enhance carbon storage in forests. Managing for forest carbon under changing climatic conditions underscores a need for resources that help identify adaptation actions that align with carbon management. We developed the Forest Carbon Management Menu to help translate broad carbon management concepts into actionable tactics that help managers reduce risk from expected climate impacts in order to meet desired management goals. We describe examples…”

As Canada’s forests become carbon bombs, Ottawa pushes the crisis off the books
by Barry Saxifrage on, March 30, 2020. (See NSFN: Canada’s faulty forest carbon accounting laid bare 30Mar2020). From the Saxifrage article: “In summary, the government’s own data shows that Canada’s managed forests, and the wood taken out of them each year, have become one of our country’s largest climate pollution sources. Logging now extracts vastly more carbon than is growing back — tipping our forests from weak CO2 sinks into massive CO2 emitters. Rather than taking responsibility for our actions that are driving this new threat, the government is trying to push it all off the books through “creative” accounting, generational burden shifting and fake “offsets” schemes.”

The Effects of Forest Management on Carbon Storage in Ontario’s Forests
Colombo, S.J. et al., 2005. Queen’s Printer for Ontario. 126 pp, with references. A dated report but very useful for understanding how forest practices might affect C balances. “This report examines how forest management can affect the carbon (C) balance of Ontario’s forests. Ten forest management activities organized in four themes were examined: stand establishment (site preparation, planting, and vegetation management), growth enhancement (thinning, fertilization, and genetic improvement), forest protection (from forest fires, and insect and disease infestations), and harvesting (controlling the area occupied by roads, skid trails and landings, and reducing the area disturbed by harvesting).

Forest management for mitigation and adaptation to climate change: Insights from long-term silviculture experiments
Anthony W. D’Amato et al., Forest Ecology and Management Volume 262, Issue 5, 1 September 2011, Pages 803-816
Key Paper and relevant to NS. Thinning and carbon balances explored.

Understanding the timing and variation of greenhouse gas emissions of forest bioenergy systems
M. Roder et al., 2019. Biomass and Bioenergy Volume 121, February 2019, Pages 99-114
•Net GHG balance shows GHG reduction potential of forest bioenergy is limited.
•Results are dependent on methods, system boundaries and reference system.
•Mitigation potential depends on forest management and whole forest product basket.
•Multi-level governance framework require to track wider impacts of forest bioenergy.
“no changes in soil carbon stock were assumed, as land use is not changing”
From Conclusions: “…methods like LCA, supply chain assessment and forest carbon modelling alone, do not capture the full carbon impact of systems like forests that provide several products and services. An electricity generator who sources pellets has no control over the final use of the other forest products and services, including what a forest grower does with the bioenergy feedstocks when not used for pellets. This means that governance and regulations are required at forest landscape level and the forest carbon is accounted for by including wider impacts and counterfactuals. The challenge is that a forest is multi-functional and under certain conditions, e.g. a natural disturbance, it is plausible to utilise biomass for energy even if it results in a carbon loss at the point in time but has wider sustainability benefits beyond carbon (e.g., reduced risk of disturbance, increased, re-forestation of a health stand, additional income). A solution could be that forest growers maintain a carbon account of their forest that is required at point of sale for renewable energy to prove its carbon sequestration or carbon stocks and emissions. This would require a multi-level governance framework that monitors the trail and appropriate counterfactuals of the forest/product carbon at system level considering the multi-functional (including services), multi-sectoral and international dimension of forests and bioenergy beyond energy and carbon. This would also mean that the categorisation of residues/wastes in terms of accounting and counterfactuals is likely to be particularly significant.”