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No. 377: Assessment of conservation status for terrestrial habitat types. Article 17 reporting 2019

Nygaard, B., Damgaard, C., Bladt, J. & Ejrnæs, R. 2020. Fagligt grundlag for vurdering af bevaringsstatus for terrestriske naturtyper. Artikel 17-rapporteringen 2019. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 194 s. - Videnskabelig rapport nr. 377. http://dce2.au.dk/pub/SR377.pdf

Summary      

Every six years, Denmark reports the conservation status of habitats and species to the European Commission under Article 17 of the Habitats Directive. The present report serves as documentation for the assessments of range, area, and structure and function for 34 open and 10 forest-covered terrestrial habitat types that were included in the Danish reporting to the EU in August 2019. For each habitat type, conservation status has been assessed for each of the two biogeographical regions that Denmark is part of (the Atlantic and the Continental region). Of the 44 terrestrial habitat types, seven occur only in the Continental region and, thus, 81 status assessments have been performed.

For 42 of the 44 terrestrial habitat types and 98% of the assessments, the range (i.e. the outer limits of the habitat distribution) is assessed as favourable (FV) and large enough to allow the long-term viability of the habitat, including the significant ecological variations. It is unknown whether the range of Galio-Carpinetum oak-hornbeam forests (9170) is large enough, and for Northern Atlantic wet heaths with Erica tetralix (4010) in the Continental region, the range is insufficient for long-term maintenance of the habitat type. For all 44 habitat types, the short-term trend in range area is considered to be stable.

The surface area is favourable (FV) for 32 terrestrial habitat types in both biogeographical regions and for another three habitat types in one of the two biogeographical regions, corresponding to 78% of the assessments. The surface area is large enough for long-term maintenance throughout the range of the habitat type, and the short-term trend is stable, uncertain or unknown.

The surface area is unfavourable-inadequate (U1) for five terrestrial habitat types in at least one of the biogeographical regions, corresponding to 7% of the assessments. This applies to Depressions on peat substrates of the Rhynchosporion (7150) in both biogeographical regions, as well as Salicornia and other annuals colonising mud and sand (1310), Dry sand heaths with Calluna and Genista (2310), Inland dunes with open Corynephorus and Agrostis grasslands (2330) and Active raised bogs (7110) in the Continental region.

The surface area is unfavourable-bad (U2) for eight terrestrial habitat types in at least one of the biogeographical regions, corresponding to 14% of the assessments. This applies to Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (6210) in both biogeographical regions, Species-rich Nardus grasslands, on siliceous substrates in mountain areas (and submountain areas, in Continental Europe) (6230), Northern Atlantic wet heaths with Erica tetralix (4010), European dry heaths (4030), Molinia meadows on calcareous, peaty or clayey-siltladen soils (Molinion caeruleae) (6410) and Galio-Carpinetum oak-hornbeam forests (9170) in the Continental region, as well as Salicornia and other annuals colonising mud and sand (1310) and Active raised bogs (7110) in the Atlantic. For Northern Atlantic wet heaths with Erica tetralix (4010) and European dry heaths (4030) in the Atlantic region, the surface area is considered to be large enough, but decreasing due to declining dwarf shrub cover (thus unfavourable-bad, U2). The surface area is decreasing for the two calcareous grassland types (6120 and 6210), while it is stable for Molinia meadows on calcareous, peaty or clayey-siltladen soils (Molinion caeruleae) (6410) in the Continental region and for Active raised bogs (7110) in the Atlantic. It is unknown whether the area with Galio-Carpinetum oak-hornbeam forests (9170) is large enough, and uncertain whether the area with Salicornia and other annuals colonising mud and sand (1310) is declining due to sea level rise.

It is unknown whether the surface area of Medio-European limestone beech forests of the Cephalanthero-Fagion (9150) is a large enough to maintain a favorable conservation status in the long term.

The surface area of the habitat types is calculated from a complete mapping in the Danish Habitat areas (Special Areas of Conservation, SAC) in 2016-2018, which has been extrapolated to the biogeographic level. Due to lack of knowledge of the surface area of the habitat types outside the SACs and lack of data for the development, the assessments are in many cases associated with great uncertainty.

The status of structure and function is favourable (FV) for three terrestrial habitat types, corresponding to 5% of the assessments. This applies to Spartina swards (Spartinion maritimae) (1320) in both regions, Salicornia and other annuals colonising mud and sand (1310) in the Continental and Embryonic shifting dunes (2110) in the Atlantic region. The proportion of favourable assessments is slightly lower than in 2013 (9%).

Status of structure and function is unfavourable-inadequate (U1) for 12 terrestrial habitat types, corresponding to 19% of the assessments. This applies to Annual vegetation of drift lines (1210), Shifting dunes along the shoreline with Ammophila arenaria (white dunes) (2120) and Decalcified fixed dunes with Empetrum nigrum (2140) in both biogeographical regions, Perennial vegetation of stony banks (1220), Dry sand heaths with Calluna and Genista (2310) and Dry sand heaths with Calluna and Empetrum nigrum (2320), Active raised bogs (7110) and Transition mires and quaking bogs (7140) in Continental region as well as Salicornia and other annuals colonising mud and sand (1310), Atlantic salt meadows (Glauco-Puccinellietalia maritimae) (1330), Fixed coastal dunes with herbaceous vegetation (grey dunes) (2130) and Species-rich Nardus grasslands, on siliceous substrates in mountain areas (and submountain areas, in Continental Europe) (6230) in the Atlantic region. The proportion of unfavourable-inadequate (U1) assessments is slightly lower than in 2013 (23%).

Status of structure and function is unfavourable-bad (U2) for 60 assessments, corresponding to 74% of the total number of assessments of the 44 terrestrial habitat types. This applies to the ten forest nature types, Vegetated sea cliffs of the Atlantic and Baltic coasts (1230), Fixed coastal dunes with herbaceous vegetation (grey dunes) (2130), Dunes with Hippophae rhamnoides (2160), Humid dune slacks (2190), Coastal dunes with Juniperus spp. (2250), Inland dunes with open Corynephorus and Agrostis grasslands (2330), Northern Atlantic wet heaths with Erica tetralix (4010), European dry heaths (4030), Juniperus communis formations on heaths or calcareous grasslands (5130), Semi-natural dry grasslands and scrubland facies on calcareous substrates(Festuco-Brometalia) (6210), Molinia meadows on calcareous, peaty or clayey-siltladen soils (Molinion caeruleae) (6410), Degraded raised bogs still capable of natural regeneration (7120), Depressions on peat substrates of the Rhynchosporion (7150), Petrifying springs with tufa formation (Cratoneurion) (7220) and Alkaline fens (7230) in both regions.

The same applies to Salicornia and other annuals colonising mud and sand (1310), Atlantic salt meadows (Glauco-Puccinellietalia maritimae) (1330), Inland salt meadows (1340), Embryonic shifting dunes (2110), Dunes with Salix repens ssp. argentea (Salicion arenariea) (2170), Xeric sand calcareous grasslands (6120), Species-rich Nardus grasslands, on siliceous substrates in mountain areas (and submountain areas, in Continental Europe) (6230) and Calcareous fens with Cladium mariscus and species of the Caricion davallianae (7210) in Continental region as well as Beach embankment with perennials (1220), Dry sand heaths with Calluna and Genista (2310), Dry sand heaths with Calluna and Empetrum nigrum (2320), Active raised bogs (7110) and Transition mires and quaking bogs (7140) in the Atlantic region. The proportion of unfavourable-bad (U2) assessments of terrestrial habitats is slightly higher than in 2013 (where 68% of the assessments were unfavorable-bad).

Finally, the status of structure and function is unknown for the two types of siliceous rocky slopes (8220 and 8230), corresponding to 2% of the terrestrial habitat types.

From the Article 17-report in 2013 to 2019, a number of habitat types have changed status for structure and function. The changes are primarily due to improved data and methods as well as a clarification of the EU guidelines in relation to the thresholds of the proportion of the habitat areas in "good condition" leading to a favorable status of structure and function.

The Article 17 reporting includes an assessment of the short-term trend of structure and function, i.e. the habitat area in good condition. Monitoring data from 2004 to 2016 made it possible to derive a trend in a number of indicators for structure and function for 28 of the 44 terrestrial habitat types, including the 10 forest habitat types.

There is evidence of an overall decline in the indicators for structure and function for 12 out of the 18 non-forested habitat types monitored since 2004. This applies to Atlantic salt meadows (Glauco-Puccinellietalia maritimae) (1330), Fixed coastal dunes with herbaceous vegetation (grey dunes) (2130), Decalcified fixed dunes with Empetrum nigrum (2140), Humid dune slacks (2190), Coastal dunes with Juniperus spp. (2250), Northern Atlantic wet heaths with Erica tetralix (4010), European dry heaths (4030), Semi-natural dry grasslands and scrubland facies on calcareous substrates(Festuco-Brometalia) (6210), Species-rich Nardus grasslands, on siliceous substrates in mountain areas (and submountain areas, in Continental Europe) (6230), Transition mires and quaking bogs (7140), Petrifying springs with tufa formation (Cratoneurion) (7220) and Alkaline fens (7230).

For five habitat types, the indicators of structure and function are stable. This applies to Xeric sand calcareous grasslands (6120), Molinia meadows on calcareous, peaty or clayey-siltladen soils (Molinion caeruleae) (6410), Active raised bogs (7110), Depressions on peat substrates of the Rhynchosporion (7150) and Calcareous fens with Cladium mariscus and species of the Caricion davallianae (7210). Although it has not been possible to demonstrate a clear and unambiguous development for these habitat types, a number of indicators are deteriorating, and there is reason to pay attention to further developments. Finally, there are too few monitoring plots with Inland salt meadows (1340) for data analyses, and the short-term trend is considered unknown. The development is slightly better within the SACs for a number of the indicators examined. However, the overall trend is still a decline in the area in good condition for ten of the non-forested terrestrial habitats.

There is an overall decline in the indicators of structure and function for six out of ten forest habitat types. This applies to Luzulo-Fagetum beech forests (9110), Asperulo-Fagetum beech forests (9130), Medio-European limestone beech forests of the Cephalanthero-Fagion (9150), Sub-Atlantic and medio-European oak or oakhornbeam forests of the Carpinion betuli (9160), Old acidophilous oak woods with Quercus robur on sandy plains (9190) and Bog woodland (91D0). Although there are indications of changes in Wooded dunes of the Atlantic, Continental and Boreal region (2180), Atlantic acidophilous beech forests with Ilex and sometimes also Taxus in the shrublayer (Quercinion robori-petraeae or Ilici-Fagenion) (9120), Galio-Carpinetum oak-hornbeam forests (9170) and Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae) (91E0), it has not been possible to demonstrate a clear and unambiguous development in the studied period (2007-2016), and the trend is reported as uncertain.77.pdf