Publications

Latest

Holistic Ecological Approach for Fagus sylvatica L. Dendochrononogical Series Assessment as a Source of Information for Tree Eustress

Abstract

The paper presents an original concept for stress period as a set of years with low stem growth and the methodology for their identification and assessment. The periods of low stem growth may be considered as stress in growth caused by unfavorable ecological impacts. This stress can be seen as eustres contrary to distress leading to death of tree, as the tree is experiencing the adverse effects and increases the production of wood under better conditions. An original SPPAM application is used for the statistical processing of measured tree ring widths from sampling locations. Consideration of the stress as an integral result of environmental impacts on the growth is a kind of holistic or comprehensive approach. The set of such eustress have a respective quantitative value, related to production of biomass, oxygen and carbon dioxide reduction, i.e. the processes which manage climate. The series of stress periods have relevant quality values –frequency, duration and depth that are in relation to environmental impact and trees ecology. This approach is very convenient for the fast diagnostic of present and future state of the forest communities and for pointing stands under risk. If the sampled trees from a location have long, deep and frequently appeared eustress periods then the probability of degradation and successional changes in species composition of forest communities, and the reduction of occupied area exist. In other words the used indicator in this study is linked to climatic change, succession processes in forest species composition and trends for increasing or reducing the occupied territories. The published approach may also support the vegetation modeling and forest management. The groups of trees with similar characteristics of stress periods and also with the similar behavior to the type of climatic years could be found. These groups are a kind of functional types needed for modeling. The obtained results are also a base for the deeper or reductionist investigation on the eustress etymology.

STEM GROWTHS, FOREST COMMUNITY FUNCTIONS AND GLOBAL MODELLING

Abstract

Abstract: Annual tree rings completely reflect the complex environmental impact on trees. The total stress can be discovered considering the stem growth as an integral result of the environmental impact on trees. The proposed approach is a kind of holistic or comprehensive consideration of stress as eustress. So eustress in growth is defined as a period of low stem growth. This more pragmatic approach is very convenient for fast diagnostic of present and future forest state and can be applied for identification of communities under risk. Proposed by the authors eustress parameters (as average duration, frequency and average depth) are mathematically defined.Settled climate types of years (with corresponding annual temperature and precipitations) are related with obtained eustress parameters. Such adverse years are considered as stress years. Groups with similar parameters of eustress and with analogue reactions to the same stress years (functional types) are proposed.Such defined functional types are related to climate change,forest community structure and functions, ecological succession and change of occupied territory. They also can establish a bridge between stem growth, community functions and global vegetation modeling.

The proposed paperpresents anoriginal concept for functional types based on tree eustress. Methods for identification of proposed functional typesare also introduced. The developed SPPAMapplicationfor data processing implementsthe classical and new analysis in dendrochronology. For illustration of applied methodology, chronologies of Scotch pine from Scandinavia and Spain, respectively from 28 and 25 locations, are processed by the program.
The results obtained in this study are useful for generating of new PFT classifications, for vegetation modelling, also as a base for fast diagnostics and identification of risk related forest communities and forest management.

Biomass of Tree Layer and Regeneration in Xerothermic Oak Ecosystem  (SCI “Zapadna Stara Planina i Predbalkan”, Bulgaria)

Abstract

The xerothermic oak ecosystems are a part of the autochthonic vegetation of Bulgaria. The xerothermic oak vegetation has significant environmental, economic and social importance in Bulgaria. These facts underlie the announcement of xerothermic oak forests as protected and also as an endangered habitat (Biological Diversity Act, Annex 1; The Red Data Book of the Republic of Bulgaria, vol. 3). The studied forest ecosystem Quercus frainettoQuercus cerris belongs to habitat G1.768 Moesio-Danubian termophilous oak forest (EUNIS) or habitat 91М0 Pannonian-Balkanic turkey oak-sessile oak forests (Natura 2000).

The underground and aboveground biomass of tree layer and young tree samplings and regeneration in representative Quercus frainettoQuercus cerris ecosystem from SCI “Zapadna Stara planina i Predbalkan” was determined. The study was conducted in a semi-stationary sampling plot located in the investigated forest area. The classical methods for studying biomass (Rodin et Bazilevich, 1968; Lyubenova, 2009) were used. The biomass structure of the model trees was determined by the weight ratio of the fractions – leaves, annual branches, perennial branches, wood, bark and roots of different mean diameter. The grade of regeneration of the forest ecosystem was also determined. The data for biomass of each fraction was compared to the others. The data obtained in this study was also compared to the results of previous studies and the values in classical scales. The ecological status of the studied forest ecosystem and its functional efficiency was discussed based on the obtained results, the data for health status of xerothermic oak vegetation in SCI “Zapadna Stara planina i Predbalkan” and the climate data for the region.

The results of the research carried out are important for forest monitoring, for further utilization of oak communities and for preservation of xerothermic oak ecosystems in areas protected by Nature 2000 in Bulgaria. They can also be incorporated into the existing forest ecosystems database.

CHARACTERISTICS AND DISTRIBUTION OF XEROTHERMIC OAK ECOSYSTEMS IN SCI “ZAPADNA STARA PLANINA I PREDBALKAN” AS SUBJECT OF FUNCTIONAL RESEARCH

Aim

The present study was aimed to describe the distribution and ecological structure of xerothermic oak ecosystems in SCI “Zapadna Stara planina i Predbalkan”, which are dominated by Quercus cerris L. and Q. frainettoTen.

Poster

 

Annual Report 2013

 

Previous works

STUDY ON ECOLOGICAL DYNAMICS OF FOREST VEGETATION IN THE REGION OF EAST RHODOPI ON THE BASE OF SATELLITES, GPS AND GROUND DATA

Abstract

In this paper a study of forest vegetation in the territory of East Rodopi based on satellites, GPS and other ground-based data is presented.The local areas of forest communities in classes and their distribution depending on the topography are defined. In this study we analyzed the Normalized Deferential Vegetation Index (NDVI) between forest classes. The study is the result of cooperation between specialists from SSTRI-BAS and Sofia University. This study is the initial stage of a comprehensiveresearch on the dynamics and development of natural systems in Bulgaria.

 


ABOUT ECOLOGICAL FUNDAMENTS OF NEW GENERATION GLOBAL MODELS

Abstract

The paper deals with the ve key aspects needed for scienti c commu-nity consideration in order to optimize the global and regional modelling. The applying of some elements of ecological theory as a fundament of models ob-ject selection is recommended, as well as development of the theory of plant functional types (PFTs), improving the methods and indicators selection. The ecological systems from di erent levels of organization are considered as the adaptive complex systems (ACS). The complex relations in site and out site of these systems are discussed.

 


APPLICATION OF ONTOLOGIES AND SEMANTIC WEB FOR FACILITATION OF ECOLOGY

Abstract

The application of Ontologies in the description of biology has become widely spread. This paper presents an approach for the application of Ontology in the description of complex ecological categories as Plant Functional Types. The authors illustrate the application of two Ontology approaches of engineer-ing { usage of Uni ed Modelling Language and Semantic Web approach { usage of RDF/OWL schema languages. Both approaches are powerful enough to be used as tools for formal description and information dissemination of complex ecological categories. The conversion of both approaches in general is under development in the Object Management Group (OMG).


ECOLOGICAL SPACE MODELLING AS A PATTERN OF FOREST VEGETATION INVESTIGATION (EXAMPLE WITH BELASITSA MT., BULGARIA)

Abstract
The paper presents the results of pilot spatial modelling of forest vegeta-tion types on the northern macro slope of Belasitsa Mountain. The study was conducted on the basis of modern space technology and geo-information envi-ronment of GIS. For generating the digital model of the spatial distribution of forest vegetation, a new system complex approach is used. This allows the pos-sibility of adaptation and modification of the model for conducting ecosystem research.


SOFTWARE IMPLEMENTATION FOR STRESS PERIOD STUDIES APPLIED TO DENDROCHRONOLOGICAL ANALYSES OF G. QUERCUS L.

Abstract
The paper presents an original mathematical approach for analysing the periods with low radial growth (stress periods) of trees. This approach enables us to determine with relatively high probability the radial growth basic optimal and adverse periods, as well as to recognize the main ecological regimes causing them. In the created software, SP-PAM, parameters as: interval, cardinality (Card), coverage (Co %), average duration, frequency, amplitude, alpha, stan-dard deviation and confidence are used. The programme verification is done with data from a dendroecological research of Quercus frainetto Ten., Q. cerris L. and Q. dalechampii Ten., carried out mainly in Sofia region. The published data of the adverse growth years for oak forests in Bulgaria (1945, 1950 and 1968) is confirmed. Other adverse years for radial growth of investigated oaks are also determined.

 


STUDY ON ECOLOGICAL DYNAMICS OF FOREST VEGETATION IN THE REGION OF EAST RHODOPI ON THE BASE OF SATELLITES, GPS AND GROUND DATA

Abstract

In this paper a study of forest vegetation in the territory of East Rodopi based on satellites, GPS and other ground-based data is presented.The local areas of forest communities in classes and their distribution depending on the topography are defined. In this study we analyzed the Normalized Deferential Vegetation Index (NDVI) between forest classes. The study is the result of cooperation between specialists from SSTRI-BAS and Sofia University. This study is the initial stage of a comprehensiveresearch on the dynamics and development of natural systems in Bulgaria.


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