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 We collected masting data from a total of 359 sources through an extensive literature review and from unpublished surveys.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

Spatial patterns and broad-scale weather cues of beech mast seeding in Europe.

Mast seeding is a crucial population process in many tree species, but its spatio-temporal patterns and drivers at the continental scale remain unknown . Using a large dataset (8000 masting observations across Europe for years 1950-2014) we analysed the spatial pattern of masting across the entire geographical range of European beech, how it is influenced by precipitation, temperature and drought, and the temporal and spatial stability of masting-weather correlations. Beech masting exhibited a general distance-dependent synchronicity and a pattern structured in three broad geographical groups consistent with continental climate regimes. Spearman's correlations and logistic regression revealed a general pattern of beech masting correlating negatively with temperature in the summer 2 yr before masting, and positively with summer temperature 1 yr before masting (i.e. 2T model). The temperature difference between the two previous summers (DeltaT model) was also a good predictor. Moving correlation analysis applied to the longest eight chronologies (74-114 yr) revealed stable correlations between temperature and masting, confirming consistency in weather cues across space and time. These results confirm widespread dependency of masting on temperature and lend robustness to the attempts to reconstruct and predict mast years using temperature data

Formal Specification of Object-Oriented Meta-Modelling

. Modelling languages such as the Unified Modeling Language are used during the early phases of system development to capture requirements and to express high-level designs. Many such languages have no universally fixed interpretations since different development projects often use key concepts, like Class, Generalization and Association, in slightly different ways. Therefore meta-modelling, i.e. the precise specification of the concepts used in a model, is of importance in order to avoid misunderstandings. The Boom framework, presented in this paper, is intended for this kind of meta-modelling. The framework consists of a collection of modelling constructs specified with a small object-oriented language. The framework is simple enough for an engineer to adjust the modelling concepts to project specific needs. It includes all necessary aspects of language specification, among them definition of abstract syntax, well-formedness rules, and dynamic semantics. To demonstrate ..

Declarative semantics of actions and instructions

A complete information modeling method must address both the process- and data-perspectives, preferably in an integrated manner (i.e., also specifying which state change each process should achieve exactly). However, most approaches either emphasize only data or only processes. And when an approach handles both data and processes, there is usually no integration of processes and data. A language must have a precise semantics if tools are to perform intelligent operations on models expressed in the language. Moreover, formal semantics helps in detecting errors in and reasoning about specifications. We give a precise, declarative, model-theoretic semantics for a large class of instruction languages that treats processes and data in an integrated manner. The instruction expressions are interpreted against a ‘state space’ (i.e., a set of ‘states’) and we consider the semantics of an instruction as the set of possible state transitions it can achieve. As a result, we can provide the integration of the different scenarios of a use case into one (textual) system sequence diagram with a well-defined semantics. We can also formally prove the semantic equivalence of several instructions, even for non-deterministic instructions. The class of instruction languages provides a fruitful similarity between the structuring mechanisms for modeling business processes, textual system sequence diagrams, and programming languages, among others. This will ease the translation towards an implementation in a software system.</p

Understanding UML: A Formal Semantics of Concurrency and Communication in Real-Time UML

We define a subset krtUML of UML which is rich enough to express all behavioural modelling entities of UML used for real-time applications, covering such aspects as active objects, dynamic object creation and destruction, dynamically changing communication topologies in inter-object communication, asynchronous signal based communication, synchronous communication using operation calls, and shared memory communication through global attributes. We define a formal interleaving semantics for this kernel language by associating with each model M krtUML a symbolic transition system STS(M ). We outline how to compile industrial real-time UML models making use of generalisation hierarchies, weak- and strong aggregation, and hierarchical statemachines into krtUML, and propose modelling guidelines for real-time applications of UML. This work provides the semantical foundation for formal verification of real-time UML models described in the companion paper [11]

An ASM Semantics of UML Derived from the Meta-model and Incorporating Actions

We present an approach towards a formal dynamic semantics for UML using ASM. We aim to remain as close as possible to the standard definition of UML and to cover the operational part of the language with particular attention to the behavior description based on actions. To remain close to the standard UML, we automatically translate the UML metamodel in ASM. This allows to take into account all the concepts and relationships contained in the standard, and to minimize the changes subsequent to the frequent updates of the standard