Oceanic bogs in initially slightly concave areas, with water input mostly derived from in-situ input of atmospheric moisture, dominated by strictly acidophilous heath and Sphagnum species whose poor decomposition under cool, strongly acidid, soggy and anoxic conditions, lead to the build-up of peaty domes.
Protection
The EU Habitat Directive, under the code 7110* (" Active raised bogs"), grants them priority protection. Some stands might be better included in 7120 ("Degraded raised bogs still capable of natural regeneration"); and, locally end ephemerally, 7150 ("Depressions on peat substrates of the Rhynchosporion") is represented in our bog complexes (protection cautionarily provided in any case by inclusion in 7110*).
Floristic Composition
Floristic Composition
Frequent species show the percentage of occurrence of species in each habitat, with higher values indicating more observations within the total number of samples. Indicator species show the fidelity of species to each habitat, with higher values indicating a stronger association, based on the IndVal metric (Dufrêne & Legendre, 1997). All species values were obtained from numerical classification (Jiménez-Alfaro et al. 2025). The classification of anthropogenic habitats (EUNIS code “V”) was conducted separately (Fernández-Pascual et al. 2025).
References
Dufrêne, M., & Legendre, P. (1997). Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecological monographs, 67(3), 345-366.
Fernández-Pascual, E., González-García, V., Ivesdal, G., Lázaro-Lobo, A., & Jiménez-Alfaro, B. (2024). Classification and Characterization of Anthropogenic Plant Communities in the Northwestern Iberian Peninsula. Applied Vegetation Science, 28(1), e70010. https://doi.org/10.1111/avsc.70010
Jiménez-Alfaro, B., González Le Barbier J., Carlón L., Álvarez Martínez JM, Espinosa del Alba, C., Fernández-Pascual, E., González-García V., Lázaro-Lobo A, Mendieta-Leiva, Roces Díaz JV (2025) Regionalization of European EUNIS habitat classification for effective ecosystem assessment. In prep.
List of phytosociological associations described in the Ibero-Atlantic region for each habitat. The association concepts mainly follow Rivas-Martinez et al. (2001), with further updates by Fernández-Prieto et al. (2023), and others.
References
Rivas-Martinez, S., Fernández González, F., Loidi Arregui, J., Fernández Lousã, M. & Penas Merino, A. (2001) Sintaxonomical checklist of vascular plant communities of Spain and Portugal to association level. Itinera Geobotanica 14., 5-341.
Fernández Prieto, J.A., Amigo, J., Bueno, A., Herrera, M., Rodríguez-Guitián, M.A. & Loidi, J. (2023) Bosques y orlas forestales de los territorios atlánticos del Noroeste Ibérico. Guineana, 23, 3–240 https://doi.org/10.1387/guineana.25055
Calluno vulgaris-Sphagnetum capillifolii
Drosero anglicae-Narthecietum ossifragi
Erico tetralicis-Trichophoretum germanici
Relations with other habitat types
A regional level IV unit is created, since the mostly geomorphological units proposed by EUNIS are hardly appliable to the relatively small Iberoatlantic bog complexes. Floristic similarity with regard to poor fens of units Q222 and Q223 may turn distinction somewhat tricky on occasions, especially when relying on mere species lists, without consideration of relative abundances. Topographical differences and the remarkably lower pH (often below 4) help in the delimitation of true bogs, less species-rich as a consequence of the more severe ecological conditions and whose appearance, with the predominance of Sphagnum hummocks, carnivorous plants and dwarf ericaceaous shrubs, is less grassy. EUNIS tried to tackle this ambiguity through the creation of its ill-defined unit Q25G ("Iberian quaking bogs"), actually very different to the true transitional mires of block Q25.
As an azonal vegetation composed by ecological specialists (able to cope with very selective edaphic conditions whose influence far exceeds that of the thermal regime), and despite the impact of drainings and artificial fertilizations, it occurs scattered across all the territory, even in climatically unsuitable submediterranean southwestern areas, where the lack of summer rains is compensated by siliceous impermeable bedrocks on which the abundant surface runoff during the rainy winters, eventually collected in concave places, hardly differs from rain water, giving rise to boggy valleys reminiscent of EUNIS block Q21 (“Oceanic valley mire“).
Regional distribution
Occurrence data show the locations of vegetation plots from SIVIM (Font, 2023) classified into habitat types by Jiménez-Alfaro et al. (2025). Distribution errors (outliers) may occur in vegetation plots with few species or transitional ecological conditions. The potential area of occupancy shows the environmental suitability predicted for each habitat (González Le Barbier et al. 2025), with higher values indicating more suitable climate and soil for the habitat.
References
Font, X. (2023). Sistema de Información de la vegetación Ibérica y Macaronésica. Version 1.6. Banc de dades de biodiversitat de Catalunya. http://www.sivim.info/sivi/.
Jiménez-Alfaro, B., González Le Barbier J., Carlón, L., Espinosa del Alba, C., Fernández-Pascual, E., González-García, V., Lázaro-Lobo, A. Adapting EUNIS habitat classification at the regional scale: a case study in the Ibero-Atlantic biogeographic region. In prep.
González Le Barbier, J., Ubaldi, T., Lenoir, J., Roces Díaz, J. & Jiménez-Alfaro, B. (2025) Modelling the area of occupancy of habitat types at different successional stages. In prep.
Known occurrences and potential area of occupancy of the habitat type in the study region.
