Bifurcation Model Of Successions In Ecosystems

Models of the long-term ecological successions are considered. Succession process is considered as step-bystep changing of dominant association. The model of open Eigen’s hypercycle has been used for modeling of the process. Qualitative analysis for three-dimension case has been carried out, and local bifurcations have been investigated. The process of succession can be interpreted as system’s choosing a proper level of complexity (or dimension) depending on the capacity of environment (the size of ecological niche). Connections between changing a state of the system and bifurcations in phase space is shown

Nonlinear theory of successions in forestry biogeocenoses: mathematical aspects

Systems analysis of biological phenomenon of succession has been carried out. The history of the subject and the current state of art are considered. Classification of both succession process as a whole and separate succession stages are proposed. Interaction between two main gears of succession – competition between plant species and their interaction with abiotic part of the biogeocoenose – are considered. Extreme nature of succession process and polygenetic structure of biogeocoenose, as a result of succession, are demonstrated

Hierarchical heterogenity of populations: modeling by the open Eigen hypercycle

The case of a biological population, which consists of sev-eral sub-populations (different kinds of the population ”so-cial” groups: families, bevies, etc.), has been considered. For description of non-trivial interactions between these groups, a model of ”open the Eigen hypercycle” has been proposed. Its bifurcation analysis for 3-dimension case has been carried out. Ecological interpretation of the results has been discussed

Дискретные эффекты в непрерывных моделях сукцессионных процесов

Модель разомкнутого гиперцикла Эйгена используется в статье для описания длительных экологических сукцессий. Проанализирован многомерный случай; показано, что во многих случаях исследование поведения n-мерной системы может быть сведено к исследованию систем меньшей размерности. Квазидискретная динамика модели объясняется через ее бифуркационные свойства, которые вызывают пошаговое изменение структуры системы.Модель розімкнутого гіперциклу Ейгена використовується в статті для опису тривалих екологічних сукцесій. Проаналізовано багатовимірний випадок; показано, що в багатьох випадках дослідження поведінки n-вимірної системи може бути зведено до дослідження систем меншої вимірності. Квазі-дискретна динаміка моделі пояснюється біфуркаційними властивостями, що викликають покрокову зміну структури системи.The purpose of the paper is to investigate non-linear properties of the system, which define discrete processes that occur in the one. The multi-dimension case of the model of open Eigen’s hypercycle has been analyzed. It is shown that in many cases the consideration of dynamics of the n -dimensional system can be simplified by partial reduction to (n -1)-dimensional cases

Percolation-based precursors of transitions in extended systems

Abrupt transitions are ubiquitous in the dynamics of complex systems. Finding precursors, i.e. early indicators of their arrival, is fundamental in many areas of science ranging from electrical engineering to climate. However, obtaining warnings of an approaching transition well in advance remains an elusive task. Here we show that a functional network, constructed from spatial correlations of the system’s time series, experiences a percolation transition way before the actual system reaches a bifurcation point due to the collective phenomena leading to the global change. Concepts from percolation theory are then used to introduce early warning precursors that anticipate the system’s tipping point. We illustrate the generality and versatility of our percolation-based framework with model systems experiencing different types of bifurcations and with Sea Surface Temperature time series associated to El Niño phenomenon.V.R.-M. was supported by the European Commission Marie-Curie ITN program (FP7-320 PEOPLE-2011-ITN) through the LINC project (Grant no. 289447). We also acknowledge support from FEDER and Spanish Ministry of Economy and Competitiveness (MINECO) through the project INTENSE@COSYP (FIS2012-30634) and from the European Commission through project LASAGNE (FP7-ICT- 318132). J.J.R. acknowledges funding from the Ramón y Cajal program of MINECO.EUR 1,165 APC fee funded by the EC FP7 Post-Grant Open Access PilotPeer reviewe

Modelling vegetation dynamics in heterogeneous pasture-woodland landscapes

Recent knowledge about tree regeneration, shifting mosaic in the herb layer or complex interactions between cattle activities, vegetation and landscape structure has allowed the development of a novel, spatially explicit, mosaic compartment model of the dynamics of silvopastoral ecosystems (WOODPAM). This deterministic model considers three hierarchical levels: the focal level is the phytocoenosis, represented by a cell or a patch in the landscape with a variable local stock density; herb and shrub communities as well as size-structured tree populations are the components of each patch at the lower level, spatially implicit; patches are aggregated in a pastoral management unit building the higher level, with an externally controlled global stock density

Fluvial geomorphic elements in modern sedimentary basins and their potential preservation in the rock record : A review

We appreciate very helpful reviews by Dr. Martin Stokes and three anonymous reviewers and editor Dr. Richard Marston. We also appreciate the encouragement for writing this paper from Dr. Timothy Horscroft. We acknowledge support of the sponsors of the Fluvial Systems Research Group consortium, BP, BG, Chevron, ConocoPhillips and Total.Peer reviewedPostprin

Analysis of The Dynamics of The Number of Mammalian Populations in The Conditions of The Southern Aral Sea

The article presents the results of research analysis of the dynamics of the number of mammalian populations in the conditions of the Southern Aral Sea Small mammals serve as bio indicators in the study of environmental conditions. Bio topic distribution, nutrition, age and sex structures were studied on the example of Microtus Ileus populations. The long-term joint dynamics of the populations of the most typical predator-prey system for this region in the conditions of the Southern Aral Sea region is investigated. It is shown that the specifics of the dynamics of natural processes in the conditions of the crisis of the Aral Sea region require the development of special simulation models taking into account the control parameters and order parameters of the destabilized ecosystem