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In the last decade, a number of cryptic species have been discovered in lichenized fungi, especially in species with a cosmopolitan or disjunctive distribution. Parmelia saxatilis is one of the most common and widely distributed species. Recent molecular studies have detected two species, P. ernstiae and P. serrana, within P. saxatilis s. lat., suggesting the existence of considerable genetic diversity that may not yet be expressed at the phenotypic level. Due to the complexity in the P. saxatilis s. lat. group, we used this as a model to study the species boundary and identify cryptic lineages. We used Phylogenetic (Bayes, ML and MP) and genetic distance approaches to analyze ITS and β-tubulin sequences. Our results confirm the existence of another cryptic lineage within P. saxatilis s. lat. This lineage is described herein as a new species, P. mayi. It forms an independent, strongly supported, monophyletic lineage, distantly related to the morphologically similar species P. ernstiae, P. saxatilis and P. serrana. Morphologically, it is indistinguishable from P. saxatilis but the new species is separated by molecular, bioclimatic, biogeographic and chemical characters. At present, P. mayi appears to have a restricted distribution in the northern Appalachian mountain territories of North America. It is found in climatic conditions ranging from hemiboreal and orotemperate to cryorotemperate ultrahyperhumid bioclimates.

This is a response to critical comments concerning the inappropriate use of the potential natural vegetation (PNV) concept made in a recent contribution to the Commentary section of this journal. We consider that the PNV concept has been misinterpreted. PNV has been used extensively in several European countries since the mid‐1950s and was never intended to be used to make a prediction of what vegetation would dominate in an area if human influence were removed. PNV maps express hypothetical assumptions of what corresponds to dominant or natural vegetation in each area. Remnants of the vegetation of the past provided by palaeopalynology and other disciplines provide valuable information for interpreting modern vegetation, but natural changes and anthropogenic influences operating over the last millennia have to be taken into account. Annex I of the Habitats Directive provides a balanced list of habitat types for implementing conservation policies within the European Union.

No abstract

Fifty-eight modern pollen surface samples from different Scots pine forest communities (Pinus sylvestris var. iberica Svoboda) in the Iberian Central System (central Spain) were palynologically and statistically analyzed (using hierarchical cluster analysis and principal component analysis) to derive correlations between pollen assemblages and environmental gradients at the sampled points. Numerical classification and ordination were performed on pollen data to assess similarities among (central Iberian)-Scots pine forest phytosociological associations. The results show a strong relationship between altitude, temperature, rainfall, arboreal cover and variations in pollen taxa percentages. The statistic discrimination of some of these forest communities has allowed us to propose three new associations.