Favourable conservation status – forest habitats

1. Favourable conservation status – forest habitats State Nature Conservancy of the Slovak republic Forest research institute Forest managment planing institute EFRA

2. Approach chosen:

4. Definitions • Clear definitions are needed for: • Terms employed (tree layer, growth class, natural regeneration, etc.) • Quantifiers, measurement units • Form of record (e.g. using mathematical symbols, description, etc.)

5. Tree species composition • Degree of approximation to the model (%) given for each particular habitat, e.g. 9410: spruce 50–100, sycamore maple0–10, sorbus aucuparia0–50 • Occurrence of invasive tree species • the least controversial indicator • sufficient knowledge on the natural tree species composition • complicated & unclear system • weak argumentation on the approximation degrees required (e.g. "what is the relevance of 30 %?") • inability to assess gene pool naturalness • inability to identify the tree species behind the change

6. Herb & shrub species • presence of a larger number of species, more complicated field assessment • extreme difficultness of exact investigation Solution: • Herb layer composition is determined by the tree layer • Most significant changes are: onset of invasive or expansive species, indicators of acidification and eutrophication, ruderal species, etc. • simple list of herbs on sites with cover by Tansley scale

7. Herb & shrub species • Simple assessment • Reflection of most distinct changes only • Inability to reflect reduction of biodiversity provided natural species are not replaced by the aforementioned species • One-sided decision on the naturalness of certain species (e.g. Urtica dioica)

8. Structure • Ambiguity of the term "structure" (arrangement of components / parts or interactions /processes within any higher hierarchical unit) • Our approach: structure limited to spatial structure of forest habitats and their groups only (age structure, structural pattern) • Unclear importance of spatial structure for the assessment of FCS

9. Spatial structure of forest habitats and / or their groups: • Horizontal structure (size and distribution of structural units) • vertical structure (multi-layeredness of forest stands) ≈ function of tree age => age structure • Close affinity of both structures. • Vertical diversity of natural forests has in managed forests been to a certain degree replaced by the mosaic of even-aged stands.

10. Other indicators of structure criterion: • natural regeneration (principal precondition of forest stand sustainability; possible listing within the forest habitat species structure) • large-diameter and biodiversity valuable trees (for some type of habitats it is a good indicator of structure, if we do not have other structure indicators; need to assess them separately; biodiversity valuable) • deadwood (biodiversity valuable; in spatial structure serves only aesthetic purposes)

11. Key issues related to structure definition • Quantification of minimal limit values for the assessment of growth class, developmental stage, tree layer... 10% • Quantification of the area limit for the layer unit and even-aged forest unit (0,30 ha) • Quantification of the minimal stocking level of the respective unit (0,3)

12. Relation between natural regeneration and developmental stage of forest stand: • Conditions for natural regeneration match the developmental stage of particular forest stands and / or seedlings and saplings cover 61 – 100 % of the area expected to be covered. • Conditions for natural regeneration don’t match the developmental stage of particular forest stands completely (gaps in a canopy, lowered density of stands) and / or seedlings and saplings cover 11 – 60 % of the area expected to be covered (including premature canopy gaps). • Conditions for natural regeneration don’t match the developmental stage of particular forest stands completely (gaps in a canopy, lowered density of stands) and / or seedlings and saplings cover 1 – 10 % of the area expected to be covered (including premature canopy gaps). • Conditions for natural regeneration are not expected (site is covered only by overmature stands) or there are conditions for natural regeneration, but for some reason the trees are not fertile.

13. Large-diameter and biodiversity valuable trees • Quantification of the minimal diameter and number of trees • absolute diameter (>... cm) vs. relative (one generation older, ?? cm larger than main / final crop) • prime difficulty: determination of a reasonable value of the above mentioned • objective: to ensure certain proportion of larger trees also in younger even-aged forest stands Deadwood • Quantification of the minimal diameter, length and number of trunks • diameter has to be an absolute value

14. Negative influences • negative agents / factors – list only, no impact on the overall FSC • forest health – result of the combined influence of negative factors; indirect assessment based on visible tree damage • broader environment impact • size and isolation / fragmentation of the site • total length of border with "negative areas"

15. Forest health • Mild damagewith no impact on tree physiological processes • Medium damagewith short-term impact on tree physiological processes • Significant damage with long-term impact on tree physiological processes • Fatal damageresulting in dieback or causing dieback within 10 years • Due consideration for damage significance • One-sided assessment • No distinction between acute and chronic damage

16. Size and isolation of the site • Minimal size of intact site or minimal total area of the site group • Lack of objective criteria for the area quantification Contact with "negative areas" such as: • Intensively managed agricultural land • Active surface quarries • Growing areas ofwindfalls and other damaged sites • Ignorance of the interrelation between the site’s size and the length of border with negative areas

17. Assessment tables of particular habitats • Is it necessary to have a separated table for each particular habitat? • What is the purpose of the tables? • Tool for field officers? • Tool for software developers? • Is the requirement for tables to be "readable" or utmost brief?

18. Differences between habitats • Large-scale vs. small-scale habitats • possible problem while comparing countries • natural vs. ± seminatural habitats • also among forest habitats we can find non-climax ones (for example 91N0*) • planar vs. linear habitats(9130 or 91E0*) • unique habitats vs. habitats similar to neighbouring ones(for example in SR 91MO vs 91G0*) • special case: dwarf pine(which is non forest habitat, but we assess dwarf pine as forest)

19. Unforeseen problem: what does habitat include? • Commonly valid: unfavourable habitat status = different habitat(9130 » 9110) • Indicators assessed depend on the site assessed. Solution: habitat excludes: • Clearcuts or windfalls larger than 3 ha • Spruce, larch, etc. monocultures larger than 0,5 ha • ...

23. Overall assessment of FCS • method of "the weakest link in the chain" vs. method "weighted average" • our solution: rather complicated weighted average with variable weights for each indicator and "state" • The weights have not been tested in practice yet.

25. traditionalism • pluses and minuses can compensate one another • pluses and minuses can compensate one another  • algorithm is difficult to understand or even to compare with other countries • usage of „triple weights": two "official" weights and limits used in each particular indicator => certain unclearness • difficult calculation and reasoning of weights