Two centuries of masting data for European beech and Norway spruce across the European continent

Tree masting is one of the most intensively studied ecological processes. It affects nutrient fluxes of trees, regeneration dynamics in forests, animal population densities, and ultimately influences ecosystem services. Despite a large volume of research focused on masting, its evolutionary ecology, spatial and temporal variability and environmental drivers are still matter of debate. Understanding the proximate and ultimate causes of masting at broad spatial and temporal scales will enable us to predict tree reproductive strategies and their response to changing environment. Here we provide broad spatial (distribution range-wide) and temporal (century) masting data for the two main masting tree species in Europe, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst.). We collected masting data from a total of 359 sources through an extensive literature review and from unpublished surveys. The dataset has a total of 1747 series and 18348 yearly observations from 28 countries and covering a time span of years 1677-2016 and 1791-2016 for beech and spruce, respectively. For each record, the following information is available: identification code; species; year of observation; proxy of masting (flower, pollen, fruit, seed, dendrochronological reconstructions); statistical data type (ordinal, continuous); data value; unit of measurement (only in case of continuous data); geographical location (country, Nomenclature of Units for Territorial Statistics NUTS-1 level, municipality, coordinates); first and last record year and related length; type of data source (field survey, peer reviewed scientific literature, grey literature, personal observation); source identification code; date when data were added to the database; comments. To provide a ready-to-use masting index we harmonized ordinal data into five classes. Furthermore, we computed an additional field where continuous series with length >4 years where converted into a five classes ordinal index. To our knowledge, this is the most comprehensive published database on species-specific masting behaviour. It is useful to study spatial and temporal patterns of masting and its proximate and ultimate causes, to refine studies based on tree-ring chronologies, to understand dynamics of animal species and pests vectored by these animals affecting human health, and it may serve as calibration-validation data for dynamic forest models.The paper was partly funded by the “Fondo di Ricerca Locale 2015-2016” of the University of Torino and by the Stiftelsen Stina Werners fond (grant SSWF 10-1/29-3 to I.D.)

Seasonal and spatial variation of stream macroinvertebrate taxonomic and functional diversity across three boreal regions

1. The exploration of biodiversity has predominantly been based on taxonomicmeasures, whereas functional diversity, a key component of biodiversity, is compar-atively understudied. Therefore, studies simultaneously investigating patterns oftaxonomic and functional diversity change in biological communities are of increas-ing interest. 2. We collated high-resolution macroinvertebrate and environmental data from 70 boreal headwater stream sites across three European countries (Germany,Finland, Sweden) to (1) investigate seasonal variation in taxonomic diversity, func-tional diversity, and redundancy, and (2) identify their potential drivers of spatialand seasonal variation. 3. Seasonal changes in boreal macroinvertebrate taxonomic diversity were decoupledfrom changes in functional diversity. Seasonal shifts in environmental conditions,including acidity and nutrient variability, drove fluctuations in taxonomic diversitywhich were far more pronounced than those of functional diversity. 4. Seasonal shifts in environmental conditions including variation in the quantity, quality, and state of organic carbon (dissolved vs particulate) facilitate an exchange of taxa, leading to taxonomically unique communities that exploit the pool of available seasonal resources. Thus, similar levels of functional diversity across seasons—evenas taxonomic diversity changes—suggest limited differences in interspecific changesin community function, potentially indicating functional resistance rooted inredundancy. 5. We highlight the spatial and seasonal discrepancies of freshwater communities,emphasising the need for both taxonomic and functional diversity patterns to beassessed in future biodiversity monitoring programmes. biological traits, community ecology, environmental drivers, freshwater ecosystems, functionalredundancy, inter-regional analysis, multivariate statistics, organic carbonSeasonal and spatial variation of stream macroinvertebrate taxonomic and functional diversity across three boreal regionspublishedVersio

Hierarchische habitat-auswahl beim sperlingskauz (Glaucidium passerinum) in alten waldbeständen des französischen voralpenlandes

Maintaining or restoring old-growth stand structures in mountain forests, including deadwood and snags provided by natural disturbances, is considered critical for the conservation of secondary cavity-nesting birds. Under current climate warming, old-growth mountain forests might become increasingly important for boreo-alpine species living in the southern part of their ranges. Here, we focused on hierarchical habitat selection by Eurasian Pygmy Owls Glaucidium passerinum in mixed mountain forests at their low latitude range limit in the southern French Prealps. We quantified Pygmy Owl habitat use at complementary hierarchical levels, from the local population to individual home ranges, by combining systematic playback counts and radio-telemetry. Mean home range sizes for breeding adult males covered 0.67 km2, ranging between 0.46 and 0.98 km2. We found evidence for Pygmy Owl habitat selection being a consistently hierarchical process, with (1) fir-dominated forests selected as the main habitat at the population level; (2) old-growth fir-dominated forest stands including edges with grassland gaps and karstic eroded areas selected at the home range level; and (3) amount of surrounding dead or decaying spruces increasing the occurrence probability of owl nesting cavities. Conserving Pygmy Owls at their low latitude range limit therefore requires the maintenance of old-growth mixed forests dominated by firs that provide these critical habitat features within a complex and heterogeneous landscape mosaic.Das Erhalten oder die Wiederherstellung alter Bestandsstrukturen in Gebirgswäldern inklusive des durch natürliche Störeinflüsse entstandenen Totholzes und der Baumstümpfe wird als ausschlaggebend für den Erhalt derjenigen Vögel betrachtet, die in sekundären Bruthöhlen nisten. Bei der derzeitigen Klimaerwärmung könnten die alten Gebirgswald-Bestände für diejenigen boreoalpinen Arten immer wichtiger werden, die am südlichen Rand ihrer Verbreitungsgebiete leben. In unserer Studie konzentrierten wir uns auf die hierarchische Habitat-Auswahl von Sperlingskäuzen (Glaucidium passerinum) in Mischwäldern auf mittlerer Höhe der südlichen französischen Voralpen. Mit einer Kombination von Radio-Telemetriedaten und systematisch erfassten Ruf-Zählungen quantifizierten wir die Nutzung der Habitate auf allen Ebenen: von der örtlichen Population bis hin zu den alltäglichen Lebensräumen der Einzeltiere. Die Größe der individuellen Lebensräume brütender, adulter Männchen reichte von 0,46 bis 0,98 km2 und betrug im Schnitt 0,67 km2. Wir fanden Hinweise darauf, dass die Habitat-Auswahl bei Sperlingskäuzen ein durchgängig hierarchischer Vorgang ist: (i) Tannen-dominierte Wälder wurden auf Populations-Ebene als wichtigste Habitate ausgewählt, (ii) auf der Ebene der individuellen Habitate lagen Altbestände von Tannenwäldern, die mit Wiesenflecken und karstig erodierten Bereichen durchsetzt war, an erster Stelle, und (iii) die Menge an toten oder vermodernden Fichten erhöhten die Wahrscheinlichkeit, Nisthöhlen der Sperlingskäuze zu finden. Sperlingskäuze auf den niedrigeren Höhen ihrer Verbreitungsgebieten zu halten, erfordert daher den Erhalt von alten, vorherrschend mit Tannen besetzten Mischwäldern, die innerhalb eines komplexen und heterogenen Landschaftsbildes diese wichtigen Auswahlkriterien für Habitate bieten