Element 4.1 Monitoring Forest Carbon Balance
Monitor the forest carbon balance is supported by four indicators in the 2011 SOFR: a provincial forest
carbon balance; Peatland carbon pools and monitoring deforestation and afforestation.
Carbon accounts for almost 50% of the weight of dry biomass in a forested ecosystem. The balance
between tree photosynthesis, taking in carbon dioxide from the atmosphere for growth, and the release of
carbon dioxide from decomposition, can significantly influence the percentage of carbon dioxide in the
Earth’s atmosphere. Carbon dioxide is considered the most important greenhouse gas due to it being the
most abundant greenhouse gas and has the most interaction within the environment. Carbon dioxide is the
predominate gas emitted by fossil fuel burning.
The amount of carbon that a particular hectare of forest land will have is dependent on many factors. The
soil type and nutrient exchange characteristics of the soils determines the growth potential, the rate of
growth, and ultimate level of biomass the hectare could support. The amount of nutrients on any particular
site can affect growth rates. Moisture regime is also significant factor for root efficiency (water that is too
limited or too abundant causes stress) largest trees grow where there is a balance between soil moisture
and aeration. Insect and Pathogen outbreaks also play a role as does the specific history of the weather.
Forests store carbon for long periods of time in tree stems, dead organic matter, and after decomposition,
a small portion is added to forest soil. Harvested wood products can also store carbon. Carbon stored in
forests is important as it keeps the stored carbon out of the atmosphere. Strategies to increase forest
carbon storage should only take place within the parameters of SFM.
Ontario assesses the provincial forest carbon balance of Crown forests by reviewing how planned forest
management affects forest carbon by changes to age of forests, their species, and the amount of forest
harvested and wood converted into products. Forest carbon modelling assists in this assessment but at
present, forest management unit carbon projections are based on models which do not consider climate
change scenarios and so may either over- or under-report expected forest productivity. Future modelling
should overcome this shortcoming.
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Peatlands (bogs and fens) have been important in mitigating climate change through their long-term
storage of carbon sequestered from the atmosphere. Ontario has the greatest amount of peatland area in
Canada. Peatlands in Ontario are being assessed but there has been minimal data collected to give any
useful trend information.
The conversion of forests to other land uses causes a release of carbon into the atmosphere. Deforestation
(i.e. land conversion) rates can affect the forest carbon balance, especially in areas like southern Ontario
where there is frequent conversion of productive forested land to urban or agricultural areas. The
proportion of the productive forest area of northern Ontario deforested was 0.02% per annum during this
reporting period, while in southern Ontario there has been a 0.06% per annum loss of productive forest
area due to deforestation.
In 2008, the 50 Million Tree Program was launched, aimed at planting 50 million trees within the province
by 2020. The program supports funding to landowners willing to convert land back to forests and will assist
Ontario in meeting its afforestation targets to lessen the impacts of deforestation.
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