By: Nicole Goldring, introduced by Gerry Ward
I invited some of Canada’s top science students to be guest bloggers. Today’s contribution comes from Nicole Goldring. I was not a judge at the CWSF: Ottawa 2008
so I cannot comment on the competitiveness of this or any other of the finalists, I will say that Nicole’s work ethic, knowledge and enthusiasm explaining her research made this project a definite stop at the fair. I also believe that Nicole’s project is an excellent example of meta-analysis showing how students can extremely carefully comb over existing data and come up with meaningful original research. Nicole was awarded the prestigious Australian National Youth Science Forum Award
at the fair.
The following is a summary of Nicole’s work.
Mountain Pine Beetle: The Silent Fire
A study to determine the release of CO2 from mature Pinus contorta after infestation from Dendroctonus ponderosae and its effect on climate change
By Nicole Goldring
“The requirement for reporting of changes in forest carbon (C) stocks under the United Nations Framework Convention on Climate Change and to the Kyoto Protocol has underlined a need for information on the deadwood pool” (Black et al. 2007). As of 2008, there has been over 13 million hectares of Pinus contorta (lodgepole pine) affected by Dendroctonus ponderosae (mountain pine beetle), in the northern and southern interior forests of British Columbia. Due to current climate change and CO2 emission notoriety largely popularized in part by Al Gore and his film “An Inconvenient Truth,” led me to realize the consequences of carbon dioxide release from decaying lodgepole pine trees after mountain pine beetle (MPB) attack and how it will affect the environment and climate change. Calculation of estimated carbon release in mature lodgepole pine have been analyzed and discussed within this study.
I composed a study to determine if mature red and grey attack lodgepole pine stands are releasing significant amounts of carbon dioxide back into the atmosphere after mountain pine beetle attack. It was then determined whether carbon release from mature lodgepole pine stands would have the ability to successfully contribute significant amounts of atmospheric (C) after MPB attack, hence, exacerbate climate change. Quantification of these numbers could then give new and valuable information on carbon found in western Canadian forest ecosystems.
Due to the mass amount of stand death in British Columbia from MPB attack, I hypothesized that decaying stands will be releasing significant amounts of carbon dioxide back into the atmosphere which will exacerbate climate change.
There were four very specific variables I had to identify and analyze. First, I determined how many hectares of lodgepole pine have been harvested since the beginning of the pine beetle epidemic. Calculation of remaining hectares that are being left to decay and decompose within the forest would therefore give the closest estimate of stand (C) release. My second step calculated the amount of carbon found in mature (approximately 75 yr old.) lodgepole pine stands/ ha and how much total (C) has the potential to be released from remaining hectares of mature red and grey attack. Variables such as soil sequestered carbon were also analyzed. The third step involved interpretation of total (C) release and whether it will be enough to exacerbate climate change. Finally, I determined the implications of future forest fires and how they will be impacting carbon release in MPB attacked forests.
Due to the aforementioned information, I found that 3,474,545 ha of lodgepole pine have been harvested since 1994, leaving behind a remaining 9,525,455 ha that are decomposing within the forests. Using the chart on the following page, calculation of carbon loss from hectares of standing live lodgepole pine minus standing dead lodgepole pine were found to release 73.5 t C / ha. This number, multiplied by the remaining 9,525,455 ha showed MPB attacked lodgepole pine forests have the ability to release 700,120,943 t C. Although this seems like an overwhelming number, this total (C) would be released very slowly over a long period of time, and not all would be released directly into the atmosphere. It is estimated that carbon release in mature lodgepole pine would take the life span of the tree, if not longer. Therefore, it is estimated that carbon release through decomposition will take within the next 75-100 years for total (C) to be released.
Regional estimates of timber volume and carbon stocks for lodgepole pine stands on forest land after clearcut harvest in the Pacific Northwest, East
It is widely understood that forest ecosystems sequester a large percentage of their total (C) within the surrounding rhizosphere. Because temperature and climate greatly affect the amount of soil sequestered carbon, it was important to determine the amount of carbon sequestered in soil in a climate similar to B.C.’s interior. Geographically, the closest and most similar climate comparitive to B.C.’s interior is the Rocky Mountain region. Studies have shown that healthy forests within this region sequester an average of 49% of their total carbon into surrounding soil. Because lodgpole pine attacked by MPB exhibits unique and accelerated decay behavior, it is expected that MPB attacked lodgepole pine will release more than 49% of its carbon into the soil due to irregular spikes in decomposition within the first three to five, and fifteen to twenty years after initial pine beetle attack. Therefore, a remaining <51% will be released back into the atmosphere where it will become integrated into global carbon sinks within the carbon cycle. These sinks including the surrounding biosphere, hydrosphere, geosphere, and atmosphere have the capability to sequester and cycle hundreds of millions of tonnes of CO2. Because the carbon cycle sequesters mass amounts of carbon in global sinks, it was found that decaying lodgepole pine trees will not be releasing enough atmospheric CO2 on an annual basis to significantly exacerbate climate change. However, due to inevitable forest fires that occur in B.C. every year, dry decaying lodgepole pine has the potential to cause catastrophic damage to the atmosphere and the environment. During forest fires, MPB attacked lodgepole pine immediately release all their retained carbon directly back into the atmosphere. Even more worriesome, hectares of live standing lodgpole pine release up to 90% more carbon.
In conclusion, over 700 million tonnes of carbon dioxide will be released from remaining unsalvaged hectares of lodgepole pine that have been attacked by mountain pine beetle within the next seventy-five to one hundred years. It is assumed that >49% will be going back into the surrounding soil where it will become integrated into the short term carbon cycle by remaining locked into the soil for several hundred years if left undisturbed. It was also assumed that the remaining <51% will be released back into the atmosphere where it will become integrated into the carbon cycle and be re-sequestered into the biosphere, hydrosphere, and geosphere. These findings however, are assuming that remaining stands will be decaying over 75-100 years and will not be impacted by annual forest fires. On an annual basis, the approximate amount of atmospheric carbon dioxide from cumulative decaying hectares is relatively small compared to fossil fuel emissions. Therefore carbon release will minimally contribute to an increase in atmospheric GHG’s, which will not be enough to exacerbate climate change. However, when inevitable forest fires do occur, the immediate release of CO2 from destroyed lodgepole trees will have the potential to release considerable amounts of carbon dioxide into the atmosphere. In the event of mass forests fires, the magnitude of carbon release will be so significant that it will be able to increase the total atmospheric CO2 by hundreds of thousands of tonnes. Therefore, it is paramount that forest harvesting strategies are immediately put into action. Because of this devastating epidemic, B.C. has lost a significant carbon sink that has ultimately turned into a carbon source.
Tobin, B., Black, K., Mcgurdy, L., and Nieuwenhuis, M. 2007. Estimates of decay rates of components of coarse woody debris in thinned Sitka spruce forests. Institute of Chartered Foresters, Dublin, Ireland.
Friedrichs, M. 2007 Regional estimates of timber volume and carbon stocks for lodgepole pine stands on forest land after clearcut harvest in the Pacific Northwest, East, American Forest & Paper Association, Appendix A19 p.77
Makinen, H., Hynynen, J., Siitonen, J., Sievanen, R. 2006. Predicting the decomposition of scots pine, Norway spruce, and birch stems in Finland. Ecol. App. 1, 1865-1879
Dr. Andrew Black, BSA, M.Sc., PhD Professor of Agroecology, University of British Columbia
Professor Susan Purdy, M.Sc., Faculty of Science, Thompson Rivers University