Josef Kyncl

Bio: Josef Kyncl is an academic researcher. The author has contributed to research in topics: Abies alba & Climate change. The author has an hindex of 8, co-authored 13 publications receiving 357 citations.

Filling the Eastern European gap in millennium-long temperature reconstructions

Abstract: Tree ring–based temperature reconstructions form the scientific backbone of the current global change debate. Although some European records extend into medieval times, high-resolution, long-term, regional-scale paleoclimatic evidence is missing for the eastern part of the continent. Here we compile 545 samples of living trees and historical timbers from the greater Tatra region to reconstruct interannual to centennial-long variations in Eastern European May–June temperature back to 1040 AD. Recent anthropogenic warming exceeds the range of past natural climate variability. Increased plague outbreaks and political conflicts, as well as decreased settlement activities, coincided with temperature depressions. The Black Death in the mid-14th century, the Thirty Years War in the early 17th century, and the French Invasion of Russia in the early 19th century all occurred during the coldest episodes of the last millennium. A comparison with summer temperature reconstructions from Scandinavia, the Alps, and the Pyrenees emphasizes the seasonal and spatial specificity of our results, questioning those large-scale reconstructions that simply average individual sites.

Placing unprecedented recent fir growth in a European‐wide and Holocene‐long context

Abstract: Forest decline played a pivotal role in motivating Europe's political focus on sustainability around 35 years ago. Silver fir (Abies alba) exhibited a particularly severe dieback in the mid-1970s, but disentangling biotic from abiotic drivers remained challenging because both spatial and temporal data were lacking. Here, we analyze 14 136 samples from living trees and historical timbers, together with 356 pollen records, to evaluate recent fir growth from a continent-wide and Holocene-long perspective. Land use and climate change influenced forest growth over the past millennium, whereas anthropogenic emissions of acidic sulfates and nitrates became important after about 1850. Pollution control since the 1980s, together with a warmer but not drier climate, has facilitated an unprecedented surge in productivity across Central European fir stands. Restricted fir distribution prior to the Mesolithic and again in the Modern Era, separated by a peak in abundance during the Bronze Age, is indicative of the long-term interplay of changing temperatures, shifts in the hydrological cycle, and human impacts that have shaped forest structure and productivity.

Fir tree-ring reconstruction of March - July precipitation in southern Moravia (Czech Republic), 1376 - 1996

Abstract: A ring-width chronology for fir Abies alba Mill. in southern Moravia compiled from historical wood and living trees was used for the dendroclimatological reconstruction of March-July precipitation for the period 1376-1996.

Effects of post-glacial phylogeny and genetic diversity on the growth variability and climate sensitivity of European silver fir

Abstract: Summary 1. Growth rates of European silver fi r( Abies alba Mill.) rapidly increased in the last century. At the same time, ring widths declined at the species southern distribution limits in the Mediterranean. Such diverse growth trends and responses have largely been attributed to regional climate conditions, but this was prior to considering the species’ post-glacial phylogeny. 2. A dendrochronological network composed of 1961 tree-ring width series (TRW) from 78 silver fir sites between 365 and 1400 m a.s.l. along the Carpathian Arc was compiled. Spatial differences in the species’ genetic diversity were investigated from genetic data of 69 silver fir populations in the region. Differences in growth variability and climate sensitivity were then related to post-glacial phylogeny and genetic diversity. 3. Significant differences in interannual and longer-term growth trends and climate responses across the Carpathian Arc were found to coincide with the geographical north–south separation of two post-glacial populations from effective refugia originating from the Apennine and Balkan peninsulas. Summer temperature was the main driver of growth in the western (Apennine) lineage, whereas ring widths in the Balkan population from the east were predominantly controlled by summer drought. Fir specimens that originated from the Balkan lineage exhibited higher genetic diversity and more regular growth dynamics and also appeared to be less sensitive to air pollution during the 1970s. 4. Synthesis. Although the phylogeny of forest trees has largely been neglected in most dendroecological studies, results here indicate the importance of different post-glacial histories for the growth sensitivity and adaptability to varying environmental factors. Decision-making under future climate warming scenarios (for building resilience through forest management) should therefore consider different phylogenetic origins.

Tree-Ring Amplification of the Early Nineteenth-Century Summer Cooling in Central Europe

Abstract: Annually resolved and absolutely dated tree-ring chronologies are the most important proxy archives to reconstruct climate variability over centuries to millennia. However, the suitability of tree- ...

On underestimation of global vulnerability to tree mortality and forest die‐off from hotter drought in the Anthropocene

Abstract: Patterns, mechanisms, projections, and consequences of tree mortality and associated broad-scale forest die-off due to drought accompanied by warmer temperatures—“hotter drought”, an emerging characteristic of the Anthropocene—are the focus of rapidly expanding literature. Despite recent observational, experimental, and modeling studies suggesting increased vulnerability of trees to hotter drought and associated pests and pathogens, substantial debate remains among research, management and policy-making communities regarding future tree mortality risks. We summarize key mortality-relevant findings, differentiating between those implying lesser versus greater levels of vulnerability. Evidence suggesting lesser vulnerability includes forest benefits of elevated [CO2] and increased water-use efficiency; observed and modeled increases in forest growth and canopy greening; widespread increases in woody-plant biomass, density, and extent; compensatory physiological, morphological, and genetic mechanisms; dampening ecological feedbacks; and potential mitigation by forest management. In contrast, recent studies document more rapid mortality under hotter drought due to negative tree physiological responses and accelerated biotic attacks. Additional evidence suggesting greater vulnerability includes rising background mortality rates; projected increases in drought frequency, intensity, and duration; limitations of vegetation models such as inadequately represented mortality processes; warming feedbacks from die-off; and wildfire synergies. Grouping these findings we identify ten contrasting perspectives that shape the vulnerability debate but have not been discussed collectively. We also present a set of global vulnerability drivers that are known with high confidence: (1) droughts eventually occur everywhere; (2) warming produces hotter droughts; (3) atmospheric moisture demand increases nonlinearly with temperature during drought; (4) mortality can occur faster in hotter drought, consistent with fundamental physiology; (5) shorter droughts occur more frequently than longer droughts and can become lethal under warming, increasing the frequency of lethal drought nonlinearly; and (6) mortality happens rapidly relative to growth intervals needed for forest recovery. These high-confidence drivers, in concert with research supporting greater vulnerability perspectives, support an overall viewpoint of greater forest vulnerability globally. We surmise that mortality vulnerability is being discounted in part due to difficulties in predicting threshold responses to extreme climate events. Given the profound ecological and societal implications of underestimating global vulnerability to hotter drought, we highlight urgent challenges for research, management, and policy-making communities.

Historical Climatology in Europe - the State of the Art

Abstract: This paper discusses the state of European research in historical climatology. This field of science and an overview of its development are described in detail. Special attention is given to the documentary evidence used for data sources, including its drawbacks and advantages. Further, methods and significant results of historical-climatological research, mainly achieved since 1990, are presented. The main focus concentrates on data, methods, definitions of the "Medieval Warm Period" and the "Little Ice Age", synoptic interpretation of past climates, climatic anomalies and natural disasters, and the vulnerability of economies and societies to climate as well as images and social representations of past weather and climate. The potential of historical climatology for climate modelling research is discussed briefly. Research perspectives in historical climatology are formulated with reference to data, methods, interdisciplinarity and impacts.

Five hundred years of gridded high-resolution precipitation reconstructions over Europe and the connection to large-scale circulation

Abstract: We present seasonal precipitation reconstructions for European land areas (30°W to 40°E/30–71°N; given on a 0.5°×0.5° resolved grid) covering the period 1500–1900 together with gridded reanalysis from 1901 to 2000 (Mitchell and Jones 2005). Principal component regression techniques were applied to develop this dataset. A large variety of long instrumental precipitation series, precipitation indices based on documentary evidence and natural proxies (tree-ring chronologies, ice cores, corals and a speleothem) that are sensitive to precipitation signals were used as predictors. Transfer functions were derived over the 1901–1983 calibration period and applied to 1500–1900 in order to reconstruct the large-scale precipitation fields over Europe. The performance (quality estimation based on unresolved variance within the calibration period) of the reconstructions varies over centuries, seasons and space. Highest reconstructive skill was found for winter over central Europe and the Iberian Peninsula. Precipitation variability over the last half millennium reveals both large interannual and decadal fluctuations. Applying running correlations, we found major non-stationarities in the relation between large-scale circulation and regional precipitation. For several periods during the last 500 years, we identified key atmospheric modes for southern Spain/northern Morocco and central Europe as representations of two precipitation regimes. Using scaled composite analysis, we show that precipitation extremes over central Europe and southern Spain are linked to distinct pressure patterns. Due to its high spatial and temporal resolution, this dataset allows detailed studies of regional precipitation variability for all seasons, impact studies on different time and space scales, comparisons with high-resolution climate models as well as analysis of connections with regional temperature reconstructions.

Five hundred years of gridded high-resolution precipitation reconstructions over Europe and the connection to large-scale

Abstract: We present seasonal precipitation reconstruc- tions for European land areas (30� Wt o 40� E/30-71� N; given on a 0.5�· 0.5� resolved grid) covering the period 1500-1900 together with gridded reanalysis from 1901 to 2000 (Mitchell and Jones 2005). Principal component regression techniques were applied to develop this dataset. A large variety of long instrumental precipitation series, precipitation indices based on documentary evidence and natural proxies (tree-ring chronologies, ice cores, corals and a speleothem) that are sensitive to precipitation sig- nals were used as predictors. Transfer functions were de- rived over the 1901-1983 calibration period and applied to 1500-1900 in order to reconstruct the large-scale pre- cipitation fields over Europe. The performance (quality estimation based on unresolved variance within the cali- bration period) of the reconstructions varies over centu- ries, seasons and space. Highest reconstructive skill was found for winter over central Europe and the Iberian Peninsula. Precipitation variability over the last half millennium reveals both large interannual and decadal fluctuations. Applying running correlations, we found major non-stationarities in the relation between large- scale circulation and regional precipitation. For several periods during the last 500 years, we identified key atmospheric modes for southern Spain/northern Mor- occo and central Europe as representations of two pre- cipitation regimes. Using scaled composite analysis, we show that precipitation extremes over central Europe and southern Spain are linked to distinct pressure patterns. Due to its high spatial and temporal resolution, this dataset allows detailed studies of regional precipitation variability for all seasons, impact studies on different time and space scales, comparisons with high-resolution cli- mate models as well as analysis of connections with re- gional temperature reconstructions.