Dimiter Ivanov

Dimiter Ivanov
Bulgarian Academy of Sciences | BAS · Institute of Biodiversity and Ecosystem Research

Prof., DSc

About

87
Publications
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Publications

Publications (87)
Article
Full-text available
The results of palynological studies of Neogene freshwater deposits of the Beli Breg Graben (West Bulgaria) are presented. We analysed pollen and spores with the aim of obtaining data about the composition and structure of fossil vegetation and climate conditions. The main vegetation paleocommunities, which existed during the fossilization process,...
Article
We reconstruct quantitatively the Middle to Upper Miocene climate evolution in the southern Forecarpathian Basin (Central Paratethys area, Northwest Bulgaria) by applying the coexistence approach to 101 well-dated palynofloras isolated from three cores. The climatic evolution is compared with changes in vegetation and palaeogeography. The Middle Mi...
Article
The results of palynological studies of the Oligo-Miocene in the western part of the Euxinian Basin (Eastern Paratethys) are based on the analysis of 57 samples from core C-136A drilled near the town of Balchik, Varna district. Some samples were barren or contained very little pollen and were not included in the analysis. Quantitative data are thus...
Article
A late Miocene paludal to lacustrine sequence from a carbonate basin in NW Bulgaria (Staniantsi Basin) is analysed displaying up to 27 rhythmically bedded sedimentary cycles. In the lower part of the sequence, the cycles consist of alternating autochthonous brown coal and marls containing diverse mollusc assemblages. The upper part of the sequence...
Article
Full-text available
The object of the study is the fossil fern Davallia haidingeri Ett. Ichnophytological and palynological methods were applied. The spores isolated from the sori of the fossil material are defined as Polipodiisporites alienus (R. Pot) Nagy.
Article
Full-text available
Data for new local palaeoflora near the village of Bersin (SW Bulgaria) are presented. Eight species of fossil plants have been identified. Eotrigonobalanus furcinervis is dominant over other species. The flora-bearing layers originate from the lower part of the Nevestino Formation, which is formed by alternating sandstone and mudstone sediments. B...
Article
Determining the diversity of past floras helps with interpreting both the history and predicting the future of vegetation change. For global-scale and regional-scale diversity studies especially, secondary data are often used but local-scale studies tend to be based on survey data that require rigorous sampling. The correct sampling strategies depe...
Article
Palaeobotany and palynology are the main direct sources of evidence for studying vegetation diversity dynamics through geological time. However, plant fossil diversity is affected by various factors other than vegetation diversity, which need to be taken into account in such studies. The use of fossil-taxa will potentially inflate perceived plant d...
Article
Full-text available
The present paper provides new data about genus Carpinus in Cenozoic sediments in Bulgaria. A summary of the available data is also presented. We focus our study on the macro-remains recorded as bract imprints. The available data for fossil bract imprints are very limited and cover a short interval of time: from the Middle Miocene to the Late Plioc...
Article
Full-text available
New fossil material from the Pernik Coal Basin (W Bulgaria) has been investigated. The flora-bearing sediments of this Basin are dated as late Oligocene-early Miocene. The macro-fossil material, which represents mainly leaf imprints , was collected from the three open-cast mines in the territory of Pernik-Bela Voda, Republika and Teva. Thirty-seven...
Article
Late Miocene sediments from the Beli Breg Coal Basin, Western Bulgaria, were investigated using spore-pollen analysis. Based on palynological characteristics, we describe dynamics and development of vegetation in the studied basin. The main types of palaeocoenoses are distinguished. The fossil flora is characterised by a variable structure of plant...
Article
A fossil vegetative cell of desmidian algae is described as a new species—Closterium mosbruggeri sp. nov. It occurs in middle Miocene (late Serravallian) sediments from Northwest Bulgaria. The present record of Closterium is the first fossil record of this genus in vegetative stage in Europe and the third in the world. The fossil species is charact...
Article
Full-text available
Species of genus Tilia still did not gain the attention they deserve by researchers and forest managers. Their importance as a significant part of forest biodiversity is expected to increase, especially in the light of changing environment, due to climate change and other factors. We present a mini-review about the genetic resources of Tilia specie...
Conference Paper
Full-text available
Genus Thymus in Bulgaria is characterized by high diversity, with 21 native species, seven of them with endemic distribution only on the Balkan Peninsula. Eighteen species were included in a pilot study on the genetic relationships among the species belonging to different sections and belonging to the same section. Six of the studied species belong...
Article
Full-text available
An analysis of selected macrofloras (leaves, fruits and seeds) from NW Bulgaria using the Coexistence аpproach method was applied to obtain quantitative data about Volhynian and Bessarabian climate in studied area. The aim of the study is to compare the climate data derived from the analysis of macrofloras and palynological data. The Middle Miocene...
Article
Full-text available
The results of palynological studies on the late Miocene freshwater deposits of the Tundzha Basin (Southeast Bulgaria, SE Europe) are presented. The basin is relatively well known in terms of geology and palaeogeography. The age of sediments in the Tundzha Basin ranges between the late Miocene to the Pliocene, based on mammal and diatom fossils. We...
Poster
Full-text available
Exploring the historical development of distribution range and related migrations of plant species can reveal important facts and trends concerning their adaptation and evolution. Many tree species are particularly suitable for such studies because of their life history characteristics and their importance from environmental and economic point of v...
Poster
Full-text available
Genera Tilia and Ulmus contain tree species called noble hardwoods. Even though they possess some remarkable characteristics, they are of relatively lesser importance, compared to the stand-forming tree species, due to their lower proportion in forests. However, the noble hardwoods could be of particular scientific interest because they demonstrate...
Article
Full-text available
The problem of paleoclimate reconstruction is an extremely interesting issue, which has been repeatedly discussed in many publications. This topic engages the attention of numerous specialists in many and various scientific disciplines. Fossil plants have vast potential as a source of information about past climatic conditions in the terrestrial re...
Article
The Miocene represents a time in Eurasia when evergreen and thermophilous dominated Paleogene vegetation was replaced by deciduous and temperate plants. Climatically, it is the transition from a greenhouse to an icehouse world, with the middle Miocene Climatic Optimum as the last warm episode of Earth history. Processes of plant evolution, transfor...
Article
Late Miocene sediments from the Sandanski Basin in southwest Bulgaria are studied by means of the spore and pollen analysis. Vegetation in the studied basin is described and its dynamics and development are traced out. The main vegetation types are distinguished. The flora of this time interval was characterized by a change in the structure of comm...
Article
Full-text available
The Coexistence Approach (CA) analysis was applied to plant macro- and microfossils from the Late Miocene to Early Pliocene sites in western Bulgaria to obtain quantitative climate data and reconstruct climate dynamics. Cal- culated new values for the Sofia macroflora confirmed a warm-temperate and humid climate with mean annual temperature (MAT) b...
Article
Full-text available
Absrtact. A detailed palynomorphological study of the Bulgarian species of genus Carduus L. (Asteraceae) is carried out for the first time by light and electron microscopy. New data have been obtained on the endemic species C. armatus, C. candicans subsp. globifer, C. kerneri subsp. austro-orientalis, C. rhodopaeus, and C. thracicus. The grouping o...
Article
The analysis of fossil palynomorh assemblages in the Late Miocene freshwater sediments of the Sofia Basin (West Bulgaria) was done to collect data on the vegetation and climate dynamics during the Late Miocene. On the basis of pollen data, we described the main palaeocomunities developed in the region. The mixed mesophytic forests dominated the veg...
Article
Full-text available
Selected Central and Southeastern European plant assemblages were com-pared to throw new light on the late Miocene evolution of European ecosys-tems and climate dynamics. A practical comparison of Bulgarian, Slovak and Czech palaeofloras provides new data about south-north trend in vegetation distribution patterns in studied area. Changes in abunda...
Article
Full-text available
This article is focused on pollen morphology of some of the most abundant fossil pollen types from late Miocene sediments in Sofia Basin (Southwest Bulgaria). The investigation includes detail morphological characteristic of the pollen types using observations under light and scanning electron microscope. Materials from the Ñ-14 core near the villa...
Article
Full-text available
This paper presents the results from taxonomical and palaeoecological analysis of the Late Miocene flora from Karlovo basin. The studied flora comes from borehole C-556 located in the eastern part of the basin. The percentage contribution of individual taxa allowed us to differentiate the main vegeta-tion types in the area. The pollen data indicate...
Article
This study correlates paleobotanical observations with chemical tracers and geological interpretation for Bulgarian coals. Two samples were studied, i.e. clay sediment with embedded twigs paleobotanically assigned to Taxodium dubium and plant material scraped off from the leaf imprint of a macrofossil. An assignment of the geological age is present...
Article
Full-text available
A new species, Ficus palamarevii sp. nov. (Moraceae), have been described from the Lower Oligocene sediments from Bulgaria. The description of the species is based on leaf imprints disclosed in volcanogenic rocks in East Rhodopes Mts. The age of fossil finding is ca. 32 Ma as proved by isotope dating. Modern analogues of the fossil species grouth i...
Conference Paper
Full-text available
The Bulgarian paleobotanical record provides important clues about the Paleogene vegetation and climate of the Tethyan Archipelago coastal areas of the evolving Eastern Paratethys. First results from a palaeoclimatic survey over a leaf flora discovered in an Oligocene volcano-sedimentary sequence, close to the village Ustren (East Rhodopes Mts., So...
Article
Full-text available
A new palynological study of the sediments from two borehole drillings in the east of the Karlovo Basin has been carried out. The investigated materials originate from grey-bluish and grey-greenish clays, as well as from diatomaceous clays above the main coal horizon. The pollen zones have been established on the basis of well-marked changes in the...
Article
The genus Isoetes is represented in Bulgaria by one species I. lacustris L. (lake quillwort). It inhabits the littoral areas of some lakes in the Pirin Mountain range. Fossil records of Isoetes in Bulgaria are very scarce. A new palynological study was conducted on sediments collected from Kupena Mire in the Western Rhodope Mountains. The results i...
Article
Full-text available
A profile 63 m thick in the Late Miocene in the Gotse-Delchev Basin (SW Bulgaria) was sampled for pollen analysis in the Kanina opencast mine. The exposed sequence comprises a basal unit with brown coal-clay cycles and clayey/siliciclastic cover layers partly representing a lacustrine facies. A total of 60 pollen samples were analyzed, but quantita...
Article
Full-text available
The results of palynological subdivision of sediments from four drilling cores in the Karlovo Basin (Central Bulgaria) are presented in the article. Spore and pollen zones of local character have been differentiated in each of the drilling cores. They are based on the characteristic changes in the percentage participation of the main pollen types o...
Article
Full-text available
The results of palynological study of sediments form outcrop PG-1 near the village of Podgumer, Sofia Basin, are presented. A total of 36 samples were analysed and 99 spores and pollen types were identified. On the basis of definitive characters of the fossil flora main palaeocommunities were described, mainly: mixed mesophytic forests, hygrophytic...
Article
Palaeobotanical methods and geochemical techniques were used to assess plant contribution and palaeoenvironment for the Staniantsi Basin, Bulgaria. The aim was to connect palaeovegetation change and climate oscillation based on pollen and statistical analysis with organic geochemical proxies for a Late Miocene lacustrine to paludial sedimentary suc...
Article
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Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. T...
Article
Full-text available
Recent studies carried out into the flora-bearing sediments of Beli Breg Lignite Basin have provided a total of 19 identified taxa at the species level, 13 of them new for that site. The new results confirm dominance of the Fagaceae family and high diversity of genus Quercus in the palaeoflora. Quercus gigas, Q. aff. acrodonta and genus Euonymus ar...
Article
Recently, continental climate evolution in Central Europe over the last 45 Ma has been reconstructed from the palaeobotanical record using a Nearest Living Relative methodology (Coexistence Approach; CA). The reconstructed climate curves document in detail the transition from almost tropical conditions in the Mid-Eocene to a temperate climate at th...
Article
The Bulgarian Palaeogene flora reveals important information concerning floristic transformation and climatic change in southeastern Europe. After the Eocene/Oligocene transition, an invasion of arctotertiary floristic elements took place in the European vegetation. This climatically forced, gradual change from a palaeotropical to an arctotertiary...
Article
Full-text available
The article presents the results of a palynological zonation of the Late Miocene sediments from the Sofia Basin (Southwest Bulgaria). The age of the 6.00-262.40 m interval of core C-14, Katina has been determined as Middle and Upper Pontian on the basis of mollusks and mammals. A rich and diversified fossil flora has been discovered too, comprising...
Article
Full-text available
This paper presents results from a palynological study on late Neogene freshwater sediments from Sofia Basin (South-west Bulgaria). Materials from core C-14, situated near the village of Katina, were investigated. As a result we determined 104 taxa pollen and spores. Based on the data obtained we discribed the main vegetation palaeocommunities, nam...
Article
The Dacian coal bearing province is located in NW Bulgaria. Coal formation is thought to be connected with desiccation of the Dacian Basin during a prolonged regression in the Late Pontian and Pliocene (Dacian–Romanian age). A Lom lignite sample was characterized via micropetrography, bulk chemical analysis, spectral methods and thermochemolysis. T...
Article
Full-text available
First results of palynological studies on Neogene freshwater deposits of Staniantsi Basin (West Bulgaria, SE Europe) are presented. The basin is rela- tively poorly known with respect to di�erent points of view in geosciences. The age of sediments in Staniantsi Basin covers the time span from the late Miocene to the Pliocene as available geological...
Article
Full-text available
The Neogene sediments of Southeast Bulgaria are poorly studied in terms of palaeobotany. This paper provides new data about the macro- and microflora from the upper undivided part of the Elhovo Formation (Toundzha Basin). Data from current palaeobotanical study contribute to the elucidation of evolution of the local and regional Late Miocene flora,...
Article
Full-text available
Pollen analysis of Miocene and Pliocene sediments from southeastern Europe and the northeastern Mediterranean is represented in pollen synthetic diagrams based on ecological criteria in order to clearly visualize changes in the composition and structure of the vegetation through time. New pollen data, together with abundant existing palynological i...
Article
Selected mega- and microfloras from Central and Southern Europe have been analysed for the time interval Tortonian/Pannonian (MN 9–12) with the Coexistence Approach to obtain quantitative palaeoclimate data. The results give a geographically differentiated picture of the Late Miocene climate in the circum-Alpine area. Spatial patterns are presented...
Article
Full-text available
The present paper focuses on palynological studies on freshwater deposits of Karlovo graben situated in Central Bulgaria. The basin is relatively well known as regards different points of view of the geological science. The age of flora-bearing sediments covers the time span Pontian - Pliocene as it is proved by geological data and diatom analysis....
Article
Full-text available
As a first attempt to provide proxy data for the quantification of Neogene latitudinal temperature gradients, fossil plant associations of the early Middle Miocene and early Late Miocene from Central and South Europe have been analysed for climate reconstruction by using the Coexistence Approach. In both time intervals the temperature gradients wit...
Article
Full-text available
An overview of the flora, vegetation and climate interpretation of the Badenian Stage in Bulgaria have been done. The Chukurovo, Satovcha and Slasten Basins in South Bulgaria, as well as the Forcarpathian and Euxinian in North Bulgaria, have been investigated from palaeobotanical and palynological viewpoint. The fossil flora from the above mentione...
Article
Full-text available
During the last few decades palaeoecologically-orientated reconstruction of environmental changes have rapidly increased because of their importance to Neogene climate evolution. In palynological studies pa-laeoecological interpretations rely on the so-called nearest living relative (NLR) philosophy, extrapolating the climate tolerances of recent p...
Article
Full-text available
The evolution of the Fagaceae is studied for the Late Oligocene - Late Pliocene time interval, based on macro- and pollenrecords from the palaeofloristic area of the Central Balkan Range. The time interval includes floras from different stratigraphic levels: Late Oligocene/ Earliest Miocene, Middle and Late Miocene (Badenian-Sarmatian-Maeotian-Pont...
Article
Full-text available
Four Neogene floras from Bulgaria were analyzed from the palaeoecological point of view: Melnik flora, Baldevo flora, Beli Brjag flora and Lozenets flora. These floras originate from relatively well-explored basins in regard of different points of view of the geological science. The age of flora-bearing sediments is Pontian - Romanian as it has bee...
Article
Full-text available
Four Neogene floras from Bulgaria were analyzed from the palaeoecological point of view: Melnik flora, Baldevo flora, Beli Brjag flora and Lozenets flora. These floras originate from relatively well-explored basins in regard of different points of view of the geological science. The age of flora-bearing sediments is Pontian - Romanian as it has bee...
Data
In this study we reconstruct quantitatively the Middle to Upper Miocene climate evolution in the southern Forecarpathian Basin (Central Paratethys area, Northwest Bulgaria) by applying the coexistence approach to 101 well-dated palynofloras isolated from three cores. The climatic evolution is compared with changes in vegetation and palaeogeography....
Article
Full-text available
The main trends in the development of the floras and vegetation of Bulgaria during the range Chattian – Villafranchian are analyzed. Differentiation of nine palaeofloristic types is done. Taking into account the data from the macro- and microfloras, these types are treated from palaeofloristic, palaeocological and phytogeographic point of view. Six...