Woodland Carbon Code projected sequestration for Stobo: EIR release

Information requested

1. It appears that the Woodland Carbon Code spreadsheet estimates or projects carbon sequestration over 100 years based on a long term average stock, which seems to include areas that have been, or will be harvested. If this is true, then this means that the projected carbon sequestered on site for commercial species is only temporary, rather than permanent. The renewal of this stock through planting is not permanent either, as this stock will also be harvested.

The current spreadsheet for Stobo (a different one to the one for the one on the registry on or around January 2024) shows projected sequestration to be around 160,000 tonnes of carbon dioxide equivalent.

2. Please could the WCC clarify if this projection of 160,000 tonnes (or thereabouts) is based on the average stock derived from forecasted growth and their timber harvesting cycles?

Please could the WCC provide the projected carbon sequestration for the Stobo site if the projected carbon sequestration for the three commercial species (Sitka spruce, Scots pine and Douglas fir) was removed from the spreadsheet, as if those species had never been planted (so there is no ground preparation either).

Response

As the information you have requested is ‘environmental information’ for the purposes of the Environmental Information (Scotland) Regulations 2004 (EIRs), we are required to deal with your request under those Regulations. We are applying the exemption at section 39(2) of the Freedom of Information (Scotland) Act 2002 (FOISA), so that we do not also have to deal with your request under FOISA.

This exemption is subject to the ‘public interest test’. Therefore, taking account of all the circumstances of this case, we have considered if the public interest in disclosing the information outweighs the public interest in applying the exemption. We have found that, on balance, the public interest lies in favour of upholding the exemption, because there is no public interest in dealing with the same request under two different regimes. This is essentially a technical point and has no material effect on the outcome of your request.

We have responded to the request as numbered above.

Response to your request

1. It appears that the Woodland Carbon Code spreadsheet estimates or projects carbon sequestration over 100 years based on a long term average stock, which seems to include areas that have been, or will be harvested. If this is true, then this means that the projected carbon sequestered on site for commercial species is only temporary, rather than permanent. The renewal of this stock through planting is not permanent either, as this stock will also be harvested.

The current spreadsheet for Stobo (a different one to the one for the one on the registry on or around January 2024) shows projected sequestration to be around 160,000 tonnes of carbon dioxide equivalent.

1. In answer to the first question, the publicly available carbon calculation shows

a. 472 hectares of Sitka spruce managed on a 45 year rotation and
b. 65 hectares of Douglas fir and Scots pine managed on an 85 year rotation.
c. 108.5 hectares or mixed broadleaves managed with minimum intervention.

All predictions under the woodland carbon code are based on the long-term average increase in carbon stock. For the conifers which are clearfelled this means we forecast the growth and sequestration through each management cycle, with the carbon stock onsite reaching a peak just before felling and effectively returning to zero at the start of the next rotation. Over several rotations the ‘long-term average’ increase in carbon stock is calculated and this is the maximum amount that can be claimed.

For example, the Sitka spruce in the calculation is modelled assuming a yield class of 24. At 45 years the model suggests such Sitka would have sequestered 652 tCO2e per hectare. However as this project will be clearfelled and restocked it can only claim the ‘long-term average’ increase in carbon which is limited to 292.5 tCO2e per hectare.

2. Please could the WCC clarify if this projection of 160,000 tonnes (or thereabouts) is based on the average stock derived from forecasted growth and their timber harvesting cycles?

Please could the WCC provide the projected carbon sequestration for the Stobo site if the projected carbon sequestration for the three commercial species (Sitka spruce, Scots pine and Douglas fir) was removed from the spreadsheet, as if those species had never been planted (so there is no ground preparation either).

In answer to the second question, the Scottish Forestry Woodland Carbon Code team do not have sufficient information about the project to know which trees are planted on which soil type using which ground preparation techniques, so it is not possible for us to totally isolate the conifer and broadleaved elements of the project.

While our aim is to provide information whenever possible, in this instance we are unable to provide the information you have requested because an exception under regulation 10(4)(a) of the EIRs (Information not held) applies to the information you have requested.

Please see Annex A for the reason this exception applies.

However, by isolating each element of the calculation by setting other elements to zero it is possible to indicate the relative proportions of the different elements as follows:

	tCO2e
Conifers	132,769
Broadleaves	52,613
Soil carbon whole site	-25,276
Emissions from establishment	-1,427
Total	158,680

Anyone with access to the publicly available spreadsheets could get an idea of the relative contributions by changing the areas of each species in column T and the areas of ground preparation in cells M35 to M40 (by setting some elements to zero it is possible to see the effect of the remaining elements).

The Woodland Carbon Code can be accessed here: https://www.woodlandcarboncode.org.uk/

Details on the Registry for the project Stobo (ID: 104000000029114) are available here:
https://mer.markit.com/br-reg/public/project.jsp?project_id=104000000029114

About FOI

The Scottish Government is committed to publishing all information released in response to Freedom of Information requests. View all FOI responses at https://www.gov.scot/foi-responses.

EIR 202500474169 - Information released - Annex A

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