Methodology

CCFPI was developed through original Irish forestry and GIS research using spatial multi-criteria and fuzzy suitability analysis. Its purpose is to assess, consistently and transparently, where Irish Sitka spruce plantations have the site conditions to support a transition from even-aged plantation management to Continuous Cover Forestry.

The index does not attempt to answer whether transition is desirable for a given owner. It answers a narrower and more testable question: whether terrain, soil and exposure conditions at a location are likely to support the structural opening that continuous cover management requires.

Six site factors are used, each standardised to a 0–100 suitability score before weighting.

Weights shown here are the prototype configuration used in this build and are treated as model assumptions pending calibration against the original research outputs.

1. Input layers
2. Standardisation
3. Fuzzy factor suitability
4. Weighting
5. Constraints
6. CCFPI score
7. Interpretation

Input raster and vector layers are clipped to the forest parcel and resampled to a common analysis grid. Each layer is standardised into a suitability surface using fuzzy membership functions, so that partial suitability is preserved rather than forced into hard categories. Standardised surfaces are combined using a weighted linear sum, and constraint layers are applied afterwards so that a site cannot be scored as suitable where a limiting condition is present.

• CCFPI score. A 0–100 index expressing the modelled potential of a Sitka spruce stand to transition to Continuous Cover Forestry.
• Transition-potential class. Very low (0–20), Low (21–40), Moderate (41–60), High (61–80), Very high (81–100).
• Factor scores. A standardised 0–100 suitability score for each of the six original site factors.
• Factor contribution. Factor score multiplied by factor weight, showing how each variable moved the index.
• Lowest-scoring factor. The factor with the lowest standardised score, reported explicitly. It is not treated as a principal constraint.
• Principal constraint. Reported only when a factor crosses an explicitly configured constraint threshold. In the prototype, No research-verified constraint rule has been applied.
• Confidence score. A weighted average of the confidence attached to each input layer, reflecting resolution and provenance.

The model is intended to be validated against field-observed stand conditions and known transition outcomes on Irish sites, with sensitivity testing across factor weights to establish how strongly each variable drives the final index.

This build has not been validated. All values shown in the application are demonstration data and the original GIS outputs are not yet connected.

• Applies to Sitka spruce plantations in Ireland only; no other species or geographies are modelled.
• Soil variables are derived from coarse national mapping and cannot resolve within-stand variation.
• Wind exposure is modelled from terrain and does not account for local shelter, edge history or recent windthrow.
• Stand-level management history, access and ownership objectives are outside the index.
• The index is a screening tool. It cannot substitute for field assessment by a qualified forestry professional.

CCFPI originates from a master's research project by Jay Gilbert on the suitability of Irish Sitka spruce plantations for transition to Continuous Cover Forestry.

Gilbert, J. Continuous Cover Forestry Potential Index (CCFPI): a spatial multi-criteria assessment of Irish Sitka spruce plantations. Full citation details to be confirmed.