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 We collected masting data from a total of 359 sources through an extensive literature review and from unpublished surveys.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.)

MASTREE+ : time-series of plant reproductive effort from six continents

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics

MASTREE+: Time-series of plant reproductive effort from six continents.

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics

Effects of drought on the induced defence reaction of Scots pine to bark beetle-associated fungi

Water stress was imposed on Scots pine saplings grown in a greenhouse. Predawn leaf water potential (ψwD) was monitored regularly while carbohydrate reserves were quantified in the phloem, xylem and shoots. Trees were inoculated in the bole with a bark beetle-associated fungus at 4 different periods of the year; the induced defence reaction was quantified 2-3 wk later by its length and the total amount of resin. A decrease in the induced reaction (length and resin quantity) was observed in the most severely stressed trees. However, no clear relationship could be established between the concentration of carbohydrates (soluble or hydrolysable) and the intensity of the defence reaction.Action d'un stress hydrique sur la réaction de défense induite du pin sylvestre contre des champignons issus d'insectes Scolytides. Un stress hydrique a été appliqué en serre sur des pins sylvestres de 6 ans. Des champignons phytopathogènes préalablement isolés d'insectes Scolytides ont été directement inoculés dans le liber de ces arbres afin de préciser l'effet de la contrainte hydrique sur les caractéristiques de la réaction locale de défense (longueur et quantité totale de résine). L'état hydrique des arbres a été suivi régulièrement par des mesures du potentiel hydrique de base au niveau des aiguilles (ψ wD). Les réserves glucidiques de l'arbre ont été dosées dans le liber, l'aubier et les pousses au moment des inoculations. Quatre séries d'expérience ont ainsi été réalisées sur les mêmes arbres, de mai à octobre 1989. Pour des potentiels de base allant jusqu'à -2 MPa, ψwD est systématiquement et négativement corrélé avec les caractéristiques de la réaction de défense dans chaque série d'expériences (tableau I). Aucune différence concernant la teneur en glucides n'apparaît entre les arbres stressés et les témoins dans les différents compartiments considérés (tableau II)

Résistance du pin sylvestre au champignon Ophiostoma ips (naturellement associé au scolytide Ips sexdentatus), effets de diverses modalités de stress hydriques

National audienc

Résistance du pin sylvestre au champignon Ophiostoma ips (naturellement associé au scolytide Ips sexdentatus), effects de diverses modalités de stress hydrique

National audienc

Effect of different water stress conditions on scots pine reaction to bark-beetle assciated fungi

International audienc

Effect of different water stress conditions on scots pine reaction to bark-beetle associated fungi

International audienc

Réponses du pin sylvestre à la dentité et au nombre de points d'inoculation réalisés avec Leptographium wingfieldii Morelet, un champignon associé aux scolytes

International audienc