Vol. 113, No. 4 * Pages 245–339 * October - December 2009

This paper presents the high-resolution stable isotope and trace element records from a stalagmite from Hungary (Kiskőhát Shaft, Bükk Mts.). Based on the variation of the isotopic and chemical composition of the carbonate deposit along the growth axis, changes in temperature and precipitation amount are assumed.
Our first results on the younger part (ca. last 1100 years) of the deposit suggest that not only major changes but several short period cycles can be recognized within the stalagmite, which are partly caused by temperature, precipitation amount, and vegetation changes. The oxygen isotope variation of the stalagmite can be explained mainly by the changes of the temperature, while carbon isotope ratios mainly reflect the changes in water recharge or precipitation amount. Combined trace element (Mg, Sr, and P) variations were used to reconstruct evapotranspiration changes.
The stalagmite recorded a generally wet and warm Medieval Warm Period, a colder but humid Little Ice Age, and several variably dry periods between.

Three programs of medieval environmental history research of fourteen sites was undertaken between 1998 and 2008 as part of the “Evolution of the Hungarian mires, peats and marshes”, “Environment history of Hungary“, and “Geoarcheological investigations of Hungary” projects. This present study was to demonstrate the facilities of paleoecological and paleoclimatological investigations (pollen, macrofossil, sediment works) completed on the core sequence of the Nádas Lake at Nagybárkány (Hungary). The Nádas Lake at Nagybárkány is a small peat-bog in the eastern Cserhát Mountains. The formation of the lake can be traced back to the late Glacial. The sediments deposited in the lakebed provide a record of climatic and hydrologic changes. A higher water level could be demonstrated from the late Glacial to the mid-Holocene, when the reed-beds covered a small area only. This was followed by a hiatus spanning about 5000 years, caused by the deepening of the lakebed during the Imperial Age, around 20 –50 AD. The water level decreased and the water quality was more eutrophic. A reed-bed evolved around the lake. Paludification started with a bulrush floating mat phase at the close of the Middle Age, ca. 1300 AD. The initiation of the Sphagnum-bog underwent similar phases as in the other Hungarian peat-bogs. Although some anthropogenic disturbances can be reconstructed in the development of the peatland, some climatic effects and authogenic processes might be separated by paleoecological analyses.

This paper presents a 258-year long precipitation reconstruction for the Balaton Highlands and the southern Bakony Mountains region. The reconstruction based on 22 living and 32 historical tree-ring width series from oak (Quercus sp.). Ring width series were standardized by regional curve standardization technique to preserve the low frequency information. Precipitation from August of the year preceding the formation of tree ring to the current July positively stimulates the growth of oaks, albeit May-June precipitation emerges as main growth regulator factor. Very dry period occurred in the late 1740s. Studied region has experienced the wettest period during the late 18th century since 1746. Since that time, a steady decreasing trend prevails over the fluctuations of regional precipitation. From this overall trend, the 1840s, 1860s, and 1940s stand out as drier periods. The post-1980s dry period was placed into a ~250 years context and found to be an unprecedented drought at the Balaton Highlands and the southern Bakony Mountains region.

In the present paper, an overview of studies and investigations, related to the field of historical climatology and impact of hydrometeorological extremes based on documentary evidence, is presented. In addition to this, earlier investigations as well as the present stage of historical climatology in Hungary are discussed, based on research studies of climatologists, meteorologists, historians, and geographers. Besides compilations and analyses on long-term climate change, case studies on weather-related extreme events and anomalies of the last thousand years (such as droughts and floods) are also included. As regards climate variability and change, an overview is provided on the research based on lake water-level changes.