Guest blog post by Itziar García-Mijangos
Grasslands represent some of the largest and most diverse biomes of the world, yet they remain undervalued and under-researched. Extending in all continents except Antarctica, they host thousands of habitat specialist endemic species, support agricultural production, people’s livelihoods based on traditional and indigenous lifestyles, and several other ecosystem services such as pollination and water regulation.
Palaearctic grasslands represent the richest habitats for vascular plants at small spatial scales but are seriously threatened due to land use change. European grasslands experienced two extreme ends of the land-use gradient, intensification of land use on productive lands and abandonment of marginal lands, and both resulted in the loss of grassland biodiversity. It is necessary to understand their biodiversity patterns and how they relate to land use to be able to design conservation and management actions. This understanding requires the harmonization and standardization of grassland classification that leads to a consistent syntaxonomy at the European level and can increase the usefulness of vegetation typologies for conservation and management.
We provide important insights to grasslands, with special focus on dry grasslands, from the western part of Europe (Navarre region, Spain), which constitutes a new step on the pan-European grassland classification. For this purpose, we used 958 relevés distributed across all the region and grassland types, 119 containing also information on bryophytes and lichens. The data used are available in EVA and GrassPlot databases.
The five phytosociological classes most represented in Navarre are distributed according to elevation, climate, soil and topographic variables. The class Lygeo-Stipetea develops in the most Mediterranean areas. On the other hand, the classes Nardetea and Elyno-Seslerietea develop at the highest elevations, linked to the highest annual precipitation and are distributed in the northern areas. Regarding soil, topographic and structural variables the class Nardetea presents the highest soil depth and is also the most acidophilous one. The class Elyno-Seslerietea is characterised by a higher cover of stones and rocks as well as higher soil organic matter content, and, together with Nardetea and Molinio-Arrhenatheretea, is the poorest in soil carbonate content. Conversely, Lygeo-Stipetea stands out by its high soil carbonate content and low soil organic matter. Molinio-Arrhenatheretea stands out for its high cover of the herb layer and cryptogams.
We would like to highlight that bryophytes and lichens, contrary to past assumptions, are core elements of these grasslands and particularly the Mediterranean ones of Lygeo-Stipetea, both in terms of biodiversity and of diagnostic species.
We provide, for the first time, an electronic expert system for grasslands in Navarre, based on diagnostic species of each hierarchical phytosociological level from class to association. This expert system can be implemented in the JUICE program and allows the unanimous assignment of any new relevé by means of its species composition to one of the different categories established, which is of enormous value particularly for practitioners. We provide, also for the first time, a detailed databased characterisation and comparison of the syntaxa in terms of their environmental conditions and biodiversity.
García-Mijangos I, Berastegi A, Biurrun I, Dembicz I, Janišová M, Kuzemko A, Vynokurov D, Ambarlı D, Etayo J, Filibeck G, Jandt U, Natcheva R, Yildiz O, Dengler J (2021) Grasslands of Navarre (Spain), focusing on the Festuco–Brometea: classification, hierarchical expert system and characterisation. Vegetation Classification and Survey 2: 195-231. https://doi.org/10.3897/VCS/2021/69614