Diversity and conservation of the Gredos Regional Park peatlands (Iberian Central System, Spain): Geomorphological and geobotanical characterisation and incoming threats

Abstract

High-mountain peatlands are essential ecosystems for habitats, biodiversity, water, and carbon cycling, but
there is little comprehensive information in central Iberia. We present results of research concerning the distribution,
geormorphology, floristic, geobotany, and habitat diversity of peatlands in the Gredos Regional Park (Iberian Central System).
We identified 72 peatlands covering 117 ha and ranging in size from 0.01 to 17.34 ha. Peatlands occur primarily in the
upper orosubmediterranean bioclimatic belt at 1775–2230 m asl. From a geomorphological point of view, 9 different
peatland typologies have been defined. Multivariate analyses (agglomerative cluster analysis and principal component
analysis) of 103 relevés allowed us to classify the sampled peatland stands into 7 plant communities and 4 European
habitats that formed along complex hydrogeomorphic conditions, and to propose a new subassociation of other community
previously described (Caricetum echinato-nigrae lycopodielletosum inundatae). The main threat to Gredensean
peatlands is pastoral pressure, which affects 15 of them intensively, mainly between the upper supramediterranean and
the lower orosubmediterranean bioclimatic belts (~1314–1700 m asl). Seven bryophytes and three vascular plants
documented in the Gredos Regional Park peatlands are included in the IUCN Red List. From the point of view of
conservation priority, the most threatened correspond to transition mires communities (Habitat 7140) growing in
oligotrophic and minerotrophic peatlands (Caricion nigrae vegetation). Particularly, the Iberian Central System endemic
Sedo lagascae-Eriophoretum latifolii association is the one that has achieved the highest score in the five criteria
considered in this regard because Meesia triquetra, a species with the category of “critically endangered”, inhabits it.