Defense of the dissertation of Shahizada Beimbetkyzy Akmagambet for the degree of Doctor of Philosophy (PhD) in the specialty «8D05107 - Biology»
At the L.N. Gumilyov Eurasian National University, a dissertation defense will be held for the degree of Doctor of Philosophy (PhD) by Shahizada Beimbetkyzy Akmagambet on the topic of «Taxonomic diversity of the Betulaceae family in the Cenozoic floras of Kazakhstan and its significance for the reconstruction of paleoclimatic and paleoecological conditions» under the educational program «8D05107 – Biology».
The dissertation was carried out at the «General Biology and Genomics education department» of L.N. Gumilyov Eurasian National University.
The language of defense is russian
Official reviewers:
Ivan Georgievich Gabrelyan — Doctor of Biological Sciences, Head of the Laboratory of Paleobotany, A. L. Takhtajan Institute of Botany, National Academy of Sciences of the Republic of Armenia (Yerevan, Armenia).
Olesya Vladimirovna Bondarenko — Candidate of Biological Sciences (Specialty 03.00.05 – Botany), Senior Research Scientist, Head of the Laboratory of Paleobotany, Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences (Vladivostok, Russian Federation).
Temporary members of the Dissertation Committee:
Astghik Sargisovna Papikyan — Candidate of Botanical Sciences (PhD), Research Scientist, A. Takhtajyan Institute of Botany, State Non-Commercial Organization (SNCO) (Yerevan, Armenia).
Orzimat Turdimatovich Turginov — Doctor of Biological Sciences (DSc), Associate Professor, Department of Botany and Genetics, Natio nal University of Uzbekistan named after Mirzo Ulugbek (Tashkent, Uzbekistan).
Margarita Yulaevna Ishmuratova — Candidate of Biological Sciences, Associate Professor, Head of the Research Park of Biotechnology and Environmental Monitoring, Research Scientist, NJSC "Karaganda Buketov University" (Karaganda, Kazakhstan).
Scientific advisors:
Aizhan Kashagankyzy Zhamangara — candidate of biological sciences, Acting Professor, School of Natural Sciences, Astana International University, Astanam Kazakhstan.
Anna Leonidovna Averyanova — candidate of biological sciences, Research Scientist, Laboratory of Paleobotany, V.L. Komarov Botanical Institute of the Russian Academy of Sciences, Saint Petersburg, Russian Federation.
The defense will take place on September 09, 2026, at 11:00 AM in the Dissertation Council for the training direction «8D051 – Biological and related sciences» in the specialty «8D05107 – Biology» of L.N. Gumilyov Eurasian National University. The defense meeting is planned to be held offline and online.
Link: https://us06web.zoom.us/j/82492782341?pwd=E6YqaHNgssaJtETtoMlWPL30WjdpVW.1
Address: Astana, Satpayev str., 2, building №1, room №302
Abstract (English): General description of the dissertation. The dissertation is devoted to a comprehensive study of the taxonomic diversity of the family Betulaceae S.F. Gray in the Cenozoic floras of Kazakhstan and to determining its significance for the reconstruction of the region’s paleoclimatic and paleoecological conditions. The study examines fossil representatives of the genera Alnus Mill., Betula L., Corylus L., Carpinus L. and Ostrya Scop., their morphological and architectural features, spatial and temporal distribution, ecological affinities, and indicator value. The research is based on the revision of paleobotanical collections, the examination of materials obtained during field expeditions, the comparison of fossil forms with their nearest living relatives, and the application of quantitative paleoclimate reconstruction methods. The results make it possible to refine the systematics of Betulaceae in the Cenozoic floras of Kazakhstan, establish patterns of their historical distribution, and substantiate the role of this family as an informative group for reconstructing ancient plant communities and climatic conditions. Relevance of the research topic. Fossil floras are an important source of data for studying the history of vegetation, the evolution of biodiversity, and climatic changes of the past. Throughout the Cenozoic, the family Betulaceae played a substantial role in the composition of temperate and boreal floras of the Northern Hemisphere. Its representatives are characterized by well-defined morphological traits and diverse ecological affinities, which makes them valuable for taxonomic analysis, paleoecological interpretation, and quantitative paleoclimate reconstruction. In Kazakhstan, representatives of Betulaceae are known from the Paleogene and Neogene floras of the Turgai, Zaysan, Northern Pre-Aral, Ili, and other basins. However, they have previously been studied mainly within individual floristic assemblages, without a comprehensive regional revision of the family, without a unified morphological and architectural analysis, and without a systematic assessment of their reconstruction potential. This has preserved ambiguities in the interpretation of individual taxa and limited the use of Betulaceae data for broader paleoecological and paleoclimatic conclusions. The relevance of the dissertation is determined by the need to clarify the species composition of Betulaceae in the Cenozoic floras of Kazakhstan, identify patterns of their spatial and temporal distribution, and substantiate the significance of the family for reconstructing the climatic and ecological dynamics of Central Asia. Object of the research is paleobotanical materials (leaf impressions) belonging to the family Betulaceae from the Cenozoic floras of Kazakhstan Subject of the research. The subject of the research is the taxonomic and morphological-architectural diversity of Betulaceae, their spatial and temporal distribution, paleoecological role, and significance for the reconstruction of paleoclimatic conditions. Aim and objectives of the research. The aim of the dissertation research is to identify the composition and patterns of taxonomic and morphological diversity of representatives of the family Betulaceae in the Cenozoic floras of Kazakhstan and to determine their significance for reconstructing the paleoecological and paleoclimatic conditions of the region. To achieve this aim, the following objectives were addressed: 1. To conduct a historiographic analysis of studies on Betulaceae in the Cenozoic floras of Kazakhstan and adjacent territories. 2. To study the morphology and leaf architecture of representatives of the genera Betula L., Alnus Mill., Corylus L., Carpinus L. and Ostrya Scop. using standardized terminology. 3. To perform a comparative morphological and architectural analysis of fossil forms and their nearest living relatives in order to clarify their taxonomic position and identify phylogenetic relationships. 4. To establish spatial and temporal patterns in the distribution of Betulaceae representatives in the Paleogene and Neogene floras of Kazakhstan. 5. To carry out quantitative paleoclimate reconstructions based on fossil floras of Kazakhstan using the Coexistence Approach (CA) and Joint Probability Density Functions (JPDF) methods. 6. To conduct a comparative analysis of morphological and architectural traits of the genera Betula, Alnus, Corylus, Carpinus and Ostrya in order to identify adaptive trends and construct a morphological matrix of the family. Research methods. The study employed morphological and architectural analysis of fossil leaf impressions, comparative morphological assessment with nearest living relatives, taxonomic revision, stratigraphic and paleofloristic analysis, as well as quantitative paleoclimate reconstruction methods, namely the Coexistence Approach (CA) and Joint Probability Density Functions (JPDF). The research materials include fossil leaf impressions of Betulaceae from the collections of the Institute of Botany and Phytointroduction, the Astana Botanical Garden, the Komarov Botanical Institute of the Russian Academy of Sciences, and the K.I. Satpayev Institute of Geological Sciences, as well as materials collected during field expeditions conducted in 2021–2024 at Cenozoic localities in Kazakhstan. Scientific novelty of the research. 1. For the first time, a comprehensive revision of the systematics of the family Betulaceae in the Cenozoic floras of Kazakhstan was carried out on the basis of morphological and architectural analysis of fossil leaf impressions. 2. The reliable species composition of Betulaceae was clarified, and the number of previously used nominal taxa was reduced from 30 to 23. 3. Diagnostic morphological characters of fossil representatives of the genera Betula, Alnus, Corylus, Carpinus and Ostrya were refined, which improved the reliability of their taxonomic interpretation. 4. An updated consolidated catalogue of Betulaceae species from Kazakhstan was compiled, indicating their stratigraphic ranges and geographic distribution in the Paleogene and Neogene. 5. Based on an integrated set of paleofloristic data, quantitative paleoclimate reconstructions of key Cenozoic floras of Kazakhstan were performed using the CA and JPDF methods, which made it possible to refine the dynamics of regional temperature and moisture conditions. 6. The main directions of ecological and morphological changes in Betulaceae during the Cenozoic of Kazakhstan were identified, reflecting the adaptation of the family to gradual climatic continentalization and aridification. 7. The significance of Betulaceae as an indicator group for stratigraphic, paleoecological, and paleoclimatic reconstructions of the Cenozoic floras of Central Asia was substantiated. Theoretical and practical significance of the work. The theoretical significance of the study lies in expanding current knowledge of the composition, evolution, morphological stability, and ecological role of Betulaceae in the Cenozoic floras of Kazakhstan. The obtained data complement existing ideas about the formation of temperate woody floras of Eurasia and the response of plant communities to climatic changes during the Paleogene and Neogene. The practical significance of the research is determined by the possibility of applying its results to the revision of paleobotanical collections, the diagnosis of fossil leaf impressions, the development of regional stratigraphic and paleoclimatic schemes, the correlation of continental Cenozoic deposits of Kazakhstan and adjacent territories, as well as to educational activities and museum-based scientific outreach. Main results submitted for defence 1. The Cenozoic floras of Kazakhstan are characterized by the wide distribution of representatives of the family Betulaceae, which formed an important component of the woody-shrub layer of Oligocene and Miocene paleofloras. Their morphology and spatial-temporal dynamics reflect key stages in the climatic and floristic evolution of the region. 2. The taxonomic revision of Betulaceae made it possible to clarify the composition of reliable species and reduce the number of nominal taxa from 30 to 23. Valid species of the genera Alnus and Betula were refined, which provided a more reliable taxonomic interpretation of Cenozoic materials from Kazakhstan. 3. Morphological and architectural leaf traits of Betulaceae representatives — venation type, marginal tooth morphology, leaf blade length-to-width ratio, and other diagnostic parameters — demonstrate a high degree of stability throughout the Cenozoic while retaining ecological plasticity. This indicates the morphological conservatism and adaptive resilience of the family. 4. The evolutionary development of Betulaceae in the Cenozoic of Kazakhstan reflects a gradual transition from mesohygrophilous forms, represented primarily by Alnus, to mesophilous and mesoxerophilous forms, which is consistent with the overall trend of climatic continentalization and aridification of the region in the Late Neogene. 5. Paleoclimate reconstructions performed for key floristic assemblages of Kazakhstan using the CA and JPDF methods indicate that the regional climate during the Oligocene and Early Miocene was warmer and wetter than at present (MAT = 14–17 °C, MAP = 900–1100 mm/year), while the Late Miocene shows a tendency toward decreasing moisture and increasing continentality. 6. The family Betulaceae is a reliable indicator group for stratigraphic, paleoecological, and paleoclimatic reconstructions, as its representatives consistently reflect changes in temperature-moisture regimes and the dynamics of ancient plant communities. Main research results and conclusions. The study confirmed the presence of five genera of the family Betulaceae in the Cenozoic floras of Kazakhstan — Alnus, Betula, Corylus, Carpinus and Ostrya — comprising 23 reliable species. The revision made it possible to refine the systematics of fossil forms, reconsider a number of previously used nominal taxa, and improve the reliability of paleobotanical identifications. It was established that representatives of Betulaceae were widely distributed in the Paleogene and Neogene floras of the major Cenozoic basins of Kazakhstan. The highest diversity of the family is recorded in Miocene assemblages, reflecting the important role of Betulaceae in temperate-warm woody communities. Morphological and architectural analysis demonstrated the stability of key diagnostic leaf characters of Betulaceae while maintaining ecological plasticity. Comparison of fossil forms with their modern analogues made it possible to refine their taxonomic interpretation and identify major adaptive trends. Paleoecological analysis revealed different ecological affinities among the genera of the family. Alnus was more strongly associated with humid floodplain and riparian habitats; Betula and Corylus characterized mesophilous forest communities; whereas Carpinus and Ostrya indicated relatively drier forest and slope habitats. The identified dynamics are consistent with increasing climatic continentality and aridification during the Late Neogene. Quantitative paleoclimate reconstructions conducted for the floras of Erzhilansay, Kushuk, Dzhungar Aktau, Kiin-Kerish, and other assemblages showed that, during the Oligocene and Early Miocene, the climate of Kazakhstan was generally warmer and wetter than today. For a number of studied floras, the mean annual temperature was reconstructed at approximately 14–17 °C, and mean annual precipitation at approximately 900–1100 mm. A trend toward decreasing moisture is traced in the Late Miocene, which corresponds to the overall direction of regional climatic reorganization. The obtained results confirm the informativeness of Betulaceae for reconstructing ancient plant communities and climatic conditions and broaden current understanding of the paleofloristic history of Central Asia. Relation of the dissertation to state-funded research projects and priority areas of science. The dissertation was completed within the framework of two state-funded research projects: – IRN AP22686786 “Application of Quantitative Methods in Paleofloristic Analysis and Paleoclimate Reconstruction in Kazakhstan at the Oligocene–Miocene Boundary”; – IRN AP19677563 “Studies of the Paleoflora and Climate of Central Kazakhstan at the Oligocene–Miocene Boundary and the Initial Stage of Regional Desertification”. The dissertation corresponds to the priority area “Intellectual Potential of the Country” within the field of science “Natural Sciences”, specifically the subsection “Ecology, Environment and Rational Use of Natural Resources”. Approbation of the work. The main provisions and results of the dissertation research were presented at international scientific events, including the NECLIME network conference in Almaty (2024), as well as at an international scientific conference in Moscow (2025), where materials on the paleoclimatic conditions of the Early Miocene of Kazakhstan based on the macrofloras of Kushuk, Aktau, and Erzhilansay were presented. In addition, the research results were discussed on 16 September 2025 at a meeting of the Laboratory of Stratigraphy and Geology of the Mesozoic and Cenozoic of the Institute of Geological Sciences. Following the discussion, the main provisions and conclusions of the dissertation were approved, and the work was recommended for further approbation and submission for defence. Publication of research results. A total of 6 scientific articles have been published on the topic of the dissertation, including 3 articles in foreign peer-reviewed scientific journals indexed in the Scopus database and 3 articles in scientific journals recommended by the Committee for Quality Assurance in Science and Higher Education of the Ministry of Science and Higher Education of the Republic of Kazakhstan. Articles published in journals indexed in Scopus 1. The Early Miocene Paleoclimate of Erzhilansay: Interpretation of Climatic Parameters Using Modern Methods // Sustainability. – 2025. – Vol. 17. – No. 1. – P. 143. 2. Canyons of the Charyn River (South-East Kazakhstan): Geological History and Geotourism // GeoJournal of Tourism and Geosites. – 2021. – Vol. 34. – No. 1. – P. 102–111. 3. Prospects for the Introduction of Betula pendula f. dalecarlica (L.F.) C.K. Schneid. in Akmolinsk Region, Kazakhstan // Caspian Journal of Environmental Sciences. – 2024. – Vol. 22. – No. 4. – P. 981–986. Articles published in journals recommended by the Committee for Quality Assurance in Science and Higher Education of the Ministry of Science and Higher Education of the Republic of Kazakhstan 1. Paleoclimate Analysis of the Early Miocene in the Kushuk Locality (Turgai Depression) Based on the Coexistence Approach Method // Bulletin of the L.N. Gumilyov Eurasian National University. Chemistry. Geography Series. – 2025. – Vol. 150. – No. 1. – P. 171–184. 2. Қиын-Керіш флорасы негізінде ерте олигоцен климатының реконструкциясын жасауда Coexistence Approach әдісін қолдану // Bulletin of the L.N. Gumilyov Eurasian National University. Chemistry. Geography Series. – 2024. – Vol. 149. – No. 4. – P. 134–147. 3. Possibilities for Reconstructing the Paleoclimate of the Paleogene and Neogene Based on the Study of Fossil Flora (Using the Example of the Paleoflora of the Uly-Zhilanshik River) // Bulletin of the L.N. Gumilyov Eurasian National University. Chemistry. Geography Series. – 2023. – Vol. 145. – No. 4. – P. 71–82. Contribution of the doctoral candidate to the preparation of publications. 1. In the article “The Early Miocene Paleoclimate of Erzhilansay: Interpretation of Climatic Parameters Using Modern Methods”, the doctoral candidate contributed to the preparation of the initial paleofloristic data on the Erzhilansay flora, their analytical processing, the implementation of quantitative paleoclimate reconstructions using the methods applied in the study, the interpretation of the obtained climatic parameters, as well as the preparation of the manuscript and discussion of the research results. 2. In the article “Canyons of the Charyn River (South-East Kazakhstan): Geological History and Geotourism”, the doctoral candidate participated in the collection and systematization of materials related to the characterization of the natural, geological, and paleontological heritage of the study area, the analysis of literature and factual data, the discussion of the scientific and applied significance of the site, and the preparation of the publication. 3. In the article “Prospects for the Introduction of Betula pendula f. dalecarlica (L.F.) C.K. Schneid. in Akmolinsk Region, Kazakhstan”, the doctoral candidate contributed to the collection and systematization of materials on the studied birch form, the analysis of the obtained data, the discussion of results related to the biological characteristics and introduction potential of the taxon, and the preparation of the publication text. 4. In the article “Paleoclimate Analysis of the Early Miocene in the Kushuk Locality (Turgai Depression) Based on the Coexistence Approach Method”, the doctoral candidate prepared the initial floristic data for the Kushuk locality, performed a quantitative reconstruction of Early Miocene climatic parameters using the Coexistence Approach, analyzed and interpreted the obtained results, and participated in manuscript preparation and the formulation of conclusions. 5. In the article “Қиын-Керіш флорасы негізінде ерте олигоцен климатының реконструкциясын жасауда Coexistence Approach әдісін қолдану”, the doctoral candidate prepared the floristic basis of the study for the Kiin-Kerish locality, reconstructed Early Oligocene climatic conditions using the Coexistence Approach, processed and interpreted the obtained data, and participated in the preparation of the publication and discussion of its main results. 6. In the article “Possibilities for Reconstructing the Paleoclimate of the Paleogene and Neogene Based on the Study of Fossil Flora (Using the Example of the Paleoflora of the Uly-Zhilanshik River)”, the doctoral candidate participated in the systematization of paleofloristic data for the Uly-Zhilanshik River basin, the analysis of their applicability to the reconstruction of Paleogene and Neogene paleoclimatic conditions, the interpretation of the obtained results, and the preparation of the publication text and formulation of the main conclusions. Volume and structure of the dissertation. The dissertation consists of an introduction, seven chapters, conclusions, a list of references, and 6 appendices. The main text of the dissertation is presented on 116 pages. The total volume of the work, including appendices, is 215 pages. The list of references includes 131 sources by domestic and foreign authors. The dissertation contains 13 tables and 17 figures.
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