Floristic elements in European vascular plants: an analysis based on Atlas Florae Europaeae

Aim To identify floristic elements in the European flora by an analysis of the distributions of species and species groups mapped in Atlas Florae Europaeae. Location Europe, as defined by Flora Europaea. Methods We analysed the native distributions of 2762 species and 33 species’ aggregates from 79 families, which represent c. 20% of the European flora. The distributional data base, derived from Atlas Florae Europaeae, includes records from 4420 50 × 50‐km UTM grid squares. We classified species into floristic elements by a three‐stage clustering procedure, which consisted of: (1) constructing a dissimilarity hierarchy by complete linkage clustering, using a distance measure based on Jaccard’s coefficient; (2) cutting the hierarchical tree at the 0.95 level to create initial clusters, and forcing small clusters to link with larger ones until the sum of within‐group pairwise distances exceeded a threshold value; and (3) checking the allocation of all species to the redefined clusters and reassigning species if appropriate, using the cosine of the angle between the species and cluster centres to measure the similarity of species to clusters. Results The clustering procedure classified 2793 taxa into 18 floristic elements, which included between 66 and 289 taxa; two species had unique, non‐overlapping distributions and could not be classified. Main conclusions The analysis highlights the floristic diversity of the mountains of central and southern Europe, and of the Mediterranean region. The floristic elements of northern latitudes and the temperate lowlands tend to be composed of wide‐ranging species and include only a low proportion of European endemics. The montane elements, including those centred on montane areas in the Mediterranean region, are composed predominantly of perennial species and include high or very high proportions of European endemics. Classifications that recognize one ‘Alpine’ and one ‘Mediterranean’ biogeographical zone in Europe fail to reflect this floristic diversity.     

Review of Paul M. Lehrer & Robert L. Woolfolk (eds.). (2021). Principles and practice of stress management (fourth edition). Guilford.

Lehrer and Woolfolk are major figures who have led the field of stress management for four decades. Here they have assembled a gifted team of expert authors, ranging from Jonathan Smith on relaxation to Alice Meuret and Thomas Ritz on capnometric training to Shirley Telles and colleagues on yoga for stress management. The text Principles and Practice of Stress Management has long provided the most comprehensive scientifically informed resource for understanding stress and stress management. The fourth edition updates the scientific research, introduces new topics, and sharpens the focus in many chapters. Nevertheless, the preface of the fourth edition emphasizes the continued relevance of this book for the lay audience, human beings seeking guidance for managing their life stress.