engleski

Microscopy and palynology side by side - case study of palaeoenvironmental conditions in the past on the area of Central Croatia

Palynology is an interdisciplinary scientific discipline related to the study of palynomorphs – microscopic structures between 5 and 500 micrometres in size. Palynology sensu stricto is a study of plants pollen and spores. However, its objects of interests are also fungal spores, algal cysts, and zoological remains – all microscopic organic structures which can be observed and analysed on 'pollen' slides [1, 2]. The role of a microscope in palynology is more than obvious – microscopic structures can be determined (or better said, interpreted) and counted only by the use of a light and/or electronic microscope. An electron microscope is significantly important in phylogenetic questions – e.g. the explanation of pollen/spores morphology and taxonomical level/relationships between plants [3]. However, in a paleoenvironmental analysis and reconstruction, a light microscope is routinely used. The focus of this lecture is on pollen, spores and non-pollen palynomorphs (fungal, algal and zoological micro remains), which are usually used to interpret the vegetation history and local changes in hydrological and trophic levels on a certain researched area. The sediment from the biggest mire in Croatia – Blatuša (central Continental Croatia), which was cored during the year 2015 served as a case study. Namely, the peat is a very good palynomorphs trap, because its low pH values and reductive conditions allowed good preservation of palynomorphs. Except palynomorphs, in the 210 cm long core sediment of the Blatuša mire, charcoal particles were also detected and analysed, as evidence of fire activities. As the final result, the interpretation of vegetation dynamics and environmental changes during the Holocene period in the narrow area of Central Croatia was based on the analysis of 31.036 pollen palynomorphs (76 palynological taxa), 1.318 non-pollen palynomorphs and 13.970 charcoal particles [4]. According to the age-depth model, the environmental history of the researched area can be traced back to ~9800 cal yrs. before present. On the regional level, during the first thousand years pine (Pinus) dominated in the woodlands, later on succeeded by beech-alder (Fagus-Alnus) forests, which dominated most of the time, and only in the Modern Period was succeeded by hornbeam (Carpinus). Furthermore, on the local level the next transition was observed: from the sedge dominated mire, through the alder carr with peatland dominated vegetation, and again the sedge dominated mire. Primary anthropogenic indicators, like Cereal pollen, were for the first time observed quite late, in the 15th century. However, one century earlier secondary anthropogenic indicators have been frequent and continuously present in the pollen diagrams. To conclude, even though the high share of non arboreal pollen type was observed from the 6th century AD (Migration Period), direct human impact on vegetation can only be traced from the Late Middle Ages to the middle of the 20th century.

charcoal, Holocene, human impact, multiproxy study, non-pollen palynomorphs, pollen, vegetation dynamics

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