Inventory of Standing Timber Inchlumpie Wood
It was decided by Ardross Community Woodland Company that for the purposes of a business plan to be submitted in order to obtain funding, it was necessary to carry out an inventory of Inchlumpie Wood to establish an estimate of the volume of marketable timber contained therein.
The area of the wood of interest for the purposes of the inventory covers 000 hectares in total andis a mixture of Sitka spruce Picea sitchensis, Scots pine Pinus sylvestris and a small amount of European larch Larix decidua. The planting was carried out in nineteen fifty.Scots pine is the dominant species and although the components do not form discrete stands it was decided, in the interests of accuracy, to treat the wood as composed of two discrete species (SP and SS), the number of sample plots obtained for each roughly reflecting the total component of that species present.
The section of the wood of interest was divided into two sections, one to the west of the forestry road from which four sample plots were taken and a larger area to the east of the road from which eight sample plots were taken. Each plot measured 0.01ha in area and the tree of the largest diameter was measured for top height. Also an equal number of point sample sweeps was taken using a Cruiser relascope with a tally factor of two.
Once top height and basal area for the sample plots (see Fig. 1 below) were collated a volume per hectare figure was established using the Forestry Commission Stand Volume Charts (FC Booklet 39; Forest Mensuration Handbook). The volume per hectare was 177m3/ha for the Scots pine component and 310m3/ha for the Sitka spruce component. This per hectare figure was then multiplied to give a total volume for the area inventoried. The total volume of marketable timber then is 0000m3. This is roughly equivalent to 0000 tonnes of timber.
Using the Forestry Commission General Yield Class Curves (FC Book 2; Thinning Control) to establish Yield Class we see that the Scots pine on the site has a YC 06 and maximum annual volume increment will be reached at age 80 years. The Sitka spruce has a YC 10 and maximum annual incremental volume will be reached at age 65 years. The spruce component then can be harvested over the next seven years in accordance with sound silvicultural and environmental practise. The pine component will not reach maximum incremental volume until around 2030.
Fig.1 Results of Data Gathered From Site Visit on 22/12/08
Scots pine Sitka spruce
Top height (m) – 16 Top height (m) - 21
Basal area per ha (m2) – 26 Basal area per ha (m2) - 34
Yield class- 6 Yield class- 10
Timber volume (m3/ha) – 177 Timber volume (m3/ha)-310
Maximumm.a.i. - 80 years old Maximum m.a.i. - 65 years old
Glossary
Top height – An approximation of the harvestable portion of the stem, not the
actual height of the tree.
Yield class- A measure of the volume gain of the crop per hectare annually.
For example, Sitka spruce with a yield class of ten will increase in
volume by ten metres cubed per hectare each year.
Maximum m.a.i. - The point at which crop timber productivity reaches its
maximum. Beyond this productivity drops off as the crop
heads toward senility and it becomes more productive to
plant a new crop. Given as age of crop after planting.