Standardised expert system method for Navarre grasslands classification based on diagnostic species

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.

Calamintho acini-Seselietum montani in Munarriz (south of Andia Range)

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.

Lygeum spartum communities in Bardenas Reales

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.

Research article:

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 FestucoBrometea: classification, hierarchical expert system and characterisation. Vegetation Classification and Survey 2: 195-231. https://doi.org/10.3897/VCS/2021/69614

Right under our noses: A novel lichen-patterned spider found on oaks in central Spain

It happened again, a previously unknown spider species, whose home is a strongly humanised European country, appears to have been quietly and patiently waiting to get noticed until very recently.

Living on the trunks of oaks in Spain, the new species would have probably been spotted decades ago, had it not been for its sophisticated camouflage, which allows the small arachnid to perfectly blend with the lichens naturally growing on the tree.

Going by the name Araneus bonali, the new species was discovered on isolated trees at the borders of cereal fields by the scientists Eduardo Morano, University of Castilla-La Mancha, and Dr Raul Bonal, University of Extremadura. Their study is published in the open access journal ZooKeys.

Curiously enough, this is the same habitat, where the team found another new spider in 2016.

“How many new species remain unknown in these isolated oaks that once formed vast forests now becomes one even more intriguing question,” say the researchers.

“Anyone going for a walk around any village or park in central Spain would have been close to the new species. However, noticing it requires not only curiosity, but also a good sight, as its lichen-like colours make up an excellent mimicry.”

Lichens growing on an oak trunk at the study site in central Spain.

The similarity between the adults and the lichens that cover the oak trunks they inhabit is remarkable. Meanwhile, the greenish juveniles live amongst the green new shoots in the oak canopy until they reach maturity.

Whether the spider uses its mimicry to avoid predators or rather surprise its prey remains open for further investigation.

The description of this new species that belongs to the popular group of orb-weavers once again stresses the need of working harder on completing the list of spiders living in the Old World, such as the countries in the Mediterranean basin – a region that certainly keeps more taxonomic surprises up his sleeve.

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Original source:

Morano E, Bonal R (2018) Araneus bonali sp. n., a novel lichen-patterned species found on oak trunks (Araneae, Araneidae). ZooKeys 779: 119-145. https://doi.org/10.3897/zookeys.779.26944

New species of spider discovered ‘next door’ at the borders of cereal fields in Spain

The image that comes to mind when we think of new species being discovered is that of scientists sampling in remote tropical forests, where humans have barely set foot in. However, new species waiting to be discovered can in fact be very close to us, even if we live in a strongly humanized continent like Europe.

Scientists Eduardo Morano, University of Castilla-La Mancha, and Dr Raul Bonal, University of Extremadura, have discovered a new species of spider, formally called Cheiracanthium ilicis, in an area which does not match the image of a pristine habitat at all.

The new species was found in a strongly humanized area in central Spain, specifically, in isolated trees at the borders of cereal fields. These trees, mainly Holm oaks (Quercus ilex), are those remaining of the former oak woodlands that once covered the Iberian Peninsula and which have been cleared for centuries.

The systematic sampling revealed the newly discovered spider had a an exclusive preference for Holm Oaks, as all individuals were collected from the trunks and branches of these trees. Therefore, it was named after this tree’s scientific name “ilicis”.PIC_1_isolated_oak

While adults measure about a centimetre in body length, juveniles are smaller and have greenish colouration that mimics new oak shoots.

The mouthparts are proportionally large, as in the case of other species of the genus, like closely related C. mildei. In the case of the latter, the mouthparts are large enough to penetrate human skin, although the effects of the poison appear mild.

From a conservation perspective, the present study puts forward the need to preserve isolated trees in agricultural landscapes. They are not only a refuge to common forest organisms but to novel species yet to be discovered as well.

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Original source:

Morano E, Bonal R (2016) Cheiracanthium ilicis sp. n. (Araneae, Eutichuridae), a novel spider species associated with Holm Oaks (Quercus ilex). ZooKeys 601: 21-39. doi: 10.3897/zookeys.601.8241