University of Eastern Finland

School of Forest Sciences

Measuring the amount of carbon bound to wood.

One of the main reasons to climate change is usage of fossil fuels like gasoline. While burning they release carbon dioxide into the atmosphere, which causes global warming. Vegetation however bounds carbon dioxide from the atmosphere. The largest and most important carbon sinks in Finland are the forests. 

The aim of the workshop is to get to know the measurement of trees and forests, and to get an idea of ​​how much carbon dioxide emissions from driving a single tree can bind.

The tree IDs to be defined are:

• Species

• Tree diameter measured with measuring scissors from a height of 1,3 meters.

• The length of the tree, m. Measured with a hypsometer using a measuring tape as an aid. Remember to add the height of the eye to the result shown by the hypsometer.

• The height of the crown line, i.e. the lowest living branch, m. Measured like length.

The students chose the trees themselves and measured the tree IDs in groups.

When the measurements are complete the results are calculated by Excel.

The sheet calculates following values:

• Stump height diameter and live canopy length for biomass models

• Trunk biomass, bark biomass, live and dead branch biomasses, leaf biomass, stump biomass and root biomass (kg). Biomasses are calculated separately by tree species using Repola's biomass component models, excluding birch leaf biomass, which is calculated using Marklund's model.

• Total biomass (kg) is calculated as the sum of these components.

• Biomasses are dry biomasses. About half of the total mass of fresh wood is water. The total mass of fresh wood is approximated by multiplying the total biomass by two.

• The amount of carbon is obtained by dividing the total biomass by two.

• From the mass of carbon, the mass of carbon dioxide is obtained with a factor of 3.67. The amount of carbon dioxide produced from a certain amount of carbon is therefore greater than the amount of carbon, because the carbon dioxide molecule also has two oxygen atoms.

• The carbon dioxide emission of a passenger car is assumed to be approx. 150 g/km, which corresponds to the average of the entire fleet of cars in Finland in 2020.

• The end result is the number of driving kilometers corresponding to the amount of carbon in the tree at the assumed emission level.

Calculating the amount of carbon bound to wood.

The biomass of the tree components and amount of carbon dioxide can be calculated based on measured tree diameter (1), height (2) and height of the lowest living branch (3). The table below shows all the formulas with which to calculate the amount of carbon bound to pine, spruce and birch.

Google sheets for calculating the amount of carbon bound to wood.

Calculate the biomass of your own yard tree by chancing the numbers of the table below.