Data on 30-year stand dynamics in an old-growth broad-leaved forest in the Kaluzhskie Zaseki State Nature Reserve, Russia

The article provides primary data on repeated tree measurements collected during two censuses on a permanent sampling plot (440 m × 200 m) established in the old-growth polydominant broad-leaved forest in the Kaluzhskie Zaseki State Nature Reserve (centre of European Russia). The time span between the inventories was 30 years, and a total of 11 578 individuals of ten tree, one shrub species, and several undefined tree species of three known genera were registered. During the surveys, tree identity, stem diameter at breast height (DBH) of 1.3 m, and life status (alive or dead) were recorded for every tree individual with DBH ≥ 5 cm. Additional attributes were determined for some individuals. Field data were digitised and compiled into the PostgreSQL database. An accurate data quality assessment, validation, and cleaning (with documentation of changes) have been performed before data standardisation according to the Darwin Core standard. Standardised data were published through the GBIF repository. From 1986 to 1988, 9811 individuals were recorded within the initial census, including 3920 Corylus avellana individual shrubs. Corylus avellana shrubs were recorded without measuring DBH. From 2016 to 2018, 7658 stems were recorded in the recensus, including 3090 living trees marked during the initial census, and 1641 other living trees reaching the DBH of at least 5 cm. Corylus avellana was not included in the recensus. Thus, over 30 years, about 65% of living tree individuals have survived, but the total number of living trees has not changed considerably. The mean diameter of shade-intolerant tree species (Quercus robur, Fraxinus excelsior, Populus tremula, and Betula spp.) has increased the most remarkably during 30 years. For these species, the increase in average diameter, along with the decrease in numbers, is associated with the death of young trees, presumably due to low illumination under the canopy. Contrastingly, shade-tolerant tree species (Ulmus glabra, Tilia cordata, Acer platanoides) increased in number, while their mean diameter increased slightly or even decreased, that evidences the successful regeneration of these species under the canopy. These data are relevant for investigating forest ecology questions at spatiotemporal scales as a model of natural succession

Methods of parameters estimation of space point markov's type processes

The method of highest pseudolikelihood for estimation of parameters of point processes with pairing interaction is proposed; a class of models based on marked Gibbs point processes is introduced. Algorithms and software for problems of simulation space distributed objects are developedAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Modelling the spatial and space-time structure of forest stands: How to model asymmetric interaction between neighbouring trees

AbstractSpatial relationships between trees play an important role in forest ecosystem and its dynamics. These relationships determine how much of the common resources are available for an individual tree and influence the growth and mortality of the tree through a competition process. The way how plants share the available resources determines the mode of competition. In the case where a tree influences another tree but not vice versa we speak about asymmetric competition, otherwise competition is symmetric. When modelling interactions between neighbouring trees it is natural to assume that the size of a tree determines its hierarchical level: the largest trees are not influenced by any other trees than the trees in the same size class, while trees in the other size classes are influenced by the other trees in the same class as well as by all larger trees. Thus, in general there are both kind of interaction between trees: symmetric and asymmetric. We take an approach to quantify the strength of the competition process between the trees which is based on the hierarchy of trees. The space-time model considered here is based on a spatial point process with time-dependent marks where the asymmetric competition is incorporated into the model by interaction kernels

Modelling the spatial structure of forest stands by multivariate point processes with hierarchical interactions

A stochastic model is applied to describethe spatial structure of a forest stand. We aim at quantifying thestrength of the competition process between the trees in terms ofinteraction within and between different size classes of trees usingmultivariate Gibbs point processes with hierarchical interactionsintroduced by H\uf6gmander and S\ue4rkk\ue4 (1999). The new modelovercomes the main limitation of the traditional use of the Gibbsmodels allowing to describe systems with non-symmetric interactionsbetween different objects. When analyzing interactions betweenneighbouring trees it is natural to assume that the size of a treedetermines its hierarchical level: the largest trees are notinfluenced by any other trees than the trees in the same size class,while trees in the other size classes are influenced by the othertrees in the same class as well as by all larger trees. In thispaper, we describe a wide range of Gibbs models with bothhierarchical and non-hierarchical interactions as well as asimulation algorithm and a parameter estimation procedure for thehierarchical models. We apply the hierarchical interaction model tothe analysis of forest data consisting of locations and diameters oftree stems

Modelling the spatial structure of forest stands by multivariate point processes with hierarchical interactions

A stochastic model is applied to describethe spatial structure of a forest stand. We aim at quantifying thestrength of the competition process between the trees in terms ofinteraction within and between different size classes of trees usingmultivariate Gibbs point processes with hierarchical interactionsintroduced by H\uf6gmander and S\ue4rkk\ue4 (1999). The new modelovercomes the main limitation of the traditional use of the Gibbsmodels allowing to describe systems with non-symmetric interactionsbetween different objects. When analyzing interactions betweenneighbouring trees it is natural to assume that the size of a treedetermines its hierarchical level: the largest trees are notinfluenced by any other trees than the trees in the same size class,while trees in the other size classes are influenced by the othertrees in the same class as well as by all larger trees. In thispaper, we describe a wide range of Gibbs models with bothhierarchical and non-hierarchical interactions as well as asimulation algorithm and a parameter estimation procedure for thehierarchical models. We apply the hierarchical interaction model tothe analysis of forest data consisting of locations and diameters oftree stems