Annual pollen traps reveal the complexity of climatic control on pollen productivity in Europe and the Caucasus

Annual PAR (pollen accumulation rates; grains cm−2year−1) were studied with modified Tauber traps situated in ten regions, in Poland (Roztocze), the Czech Republic (two regions in Krkonoše, two in Šumava), Switzerland (4 regions in the Alps), and Georgia (Lagodekhi). The time-series are 10-16years long, all ending in 2007. We calculated correlations between pollen data and climate. Pollen data are PAR summarized per region (4-7 traps selected per region) for each pollen type (9-14 per region) using log-transformed, detrended medians. Climate data are monthly temperature and precipitation measured at nearby stations, and their averages over all possible 2- to 6-month windows falling within the 20-month window ending with August, just prior to the yearly pollen-trap collection. Most PAR/climate relationships were found to differ both among pollen types and among regions, the latter probably due to differences among the study regions in the habitats of plant populations. Results shared by a number of regions can be summarized as follows. Summer warmth was found to enhance the following year's PAR of Picea, Pinus non-cembra, Larix and Fagus. Cool summers, in contrast, increase the PAR of Abies, Alnus viridis and Gramineae in the following year, while wet summers promote PAR of Quercus and Gramineae. Wetness and warmth in general were found to enhance PAR of Salix. Precipitation was found to be more important for PAR of Alnus glutinosa-type than temperature. Weather did not have an impact on the PAR of Gramineae, and possibly of Cyperaceae in the same year. Care is advised when extrapolating our results to PAR in pollen sequences, because there are large errors associated with PAR from sediments, due to the effects of taphonomy and sedimentation and high uncertainty in dating. In addition, in pollen sequences that have decadal to centennial rather than near-annual resolution, plant-interaction effects may easily out-weigh the weather signa

Preliminary results of the vegetation history in the Giant Mountains (Úpská rašelina mire and Černohorská rašelina Bog) =Předběžné výsledky k historii vegetace Krkonoš (Úpská rašelina a Černohorská rašelina)

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Palynological reconstruction of forest development around Rokytecka slat Mire

Reconstruction of forest development around Rokytecka slat mire of the Sumava Modrava Plains through 10 thousand years

Palaeogenesis of the raised bogs of the Bohemian Forest

The Bohemian Forest landscape is characterized by the montane oligo-ombrotrophic peatbogs. The palaeogenesis of them began from the shallow lakes in the Dryas 13 thousand years ago. In the Allerod, Younger Dryas, and in the Preboreal a forming of the peatbogs with mosses, and sedges was observed. In the Boreal the vegetation of shrubs composed of Vaccinium, Ericaceae, and Calluna vulgaris covered the Central plains of the Bohemian Forest, in the Atlantic the changement of Carex peat to the peat of Scheuchzeria palustris, and Eriophorum vaginatum is mentioned. In the Subboreal and Subatlantic a development of Sphagnum peat followed. The development of pattern raised bogs began in the Subatlantic

Pollen monitoring of the Bohemian Forest in the years 1996 - 2006

The results of the secular pollen monitoring research is focused on the Bohemian Forest where 19 pollen traps were installed on the vertical transects on strategy places gradually covering the areas from natural forest zones to forested-free ones. Three areas were selected in Bohemian Forest (1) the Massif of Trojmezný – Vltavský luh Upper Moldau river valley, (2) Železnohorská hornatina Uplands – Hartmanice region, and (3) Modrava - Kvilda pláně Uplands. The pollen traps were situated in the immediate vicinity of the sampling mire with a known vegetation history, next one on meso-distance at timber-line and the other on the highest peak of the selected transect zone

The thousand-year history of the Slovak Karst inferred from pollen in bat guano inside the Domica Cave (Slovakia)

A thousand years old 105 cm deep deposit of bat guano in the Domica Cave (southern Slovakia, Slovak Karst National Park) has been discovered for science, and three samples were analysed for pollen to identify the bats’ preferred foraging habitats and for insect remains to identify their diet. The bat species concerned, Rhinolophus euryale, is rare in the area, which lies at the northern margin of its distribution. The pollen record captured alder forests between 897–1024 AD, temperate light broad-leaved oak-hornbeam forests with Quercus cerris, Fraxinus ornus, Cornus mas and Corylus avellana between 1522–1800 AD, and almost recently willow shrubs. This pattern may, however, reflect local changes in the surrounding landscape where the bats hunted. Pollen of anemophilous taxa was underrepresented (e.g. Fagus), while entomophilous taxa were overrepresented (e.g. Fraxinus ornus, Loranthus europaeus, Acer, Agrostemma githago). The phenology of the encountered pollen taxa indicates that the bats used the Domica Cave mainly as spring and summer roosts. The pollen record further indicates that the bats prefer to forage in a forest–steppe landscape with open Pannonian broadleaved forests and humid temperate riparian environments. Today, this kind of landscape does not occur further north, which may explain the northern limit of this bat species at the study site

The sedimentary and remote-sensing reflection of biomass burning in Europe

Aim: We provide the first European-scale geospatial training set relating the charcoal signal in surface lake sediments to fire parameters (number, intensity and area) recorded by satellite moderate resolution imaging spectroradiometer (MODIS) sensors. Our calibration is intended for quantitative reconstructions of key fire-regime parameters by using sediment sequences of microscopic (MIC from pollen slides, particles 10-500 \ub5m) and macroscopic charcoal (MAC from sieves, particles > 100 \ub5m). Location: North-south and east-west transects across Europe, covering the mediterranean, temperate, alpine, boreal and steppe biomes. Time period: Lake sediments and MODIS active fire and burned area products were collected for the years 2012-2015. Methods: Cylinder sediment traps were installed in lakes to annually collect charcoal particles in sediments. We quantitatively assessed the relationships between MIC and MAC influx (particles/cm2/year) and the MODIS-derived products to identify source areas of charcoal and the extent to which lake-sediment charcoal is linked to fire parameters across the continent. Results: Source area of sedimentary charcoal was estimated to a 40-km radius around sites for both MIC and MAC particles. Fires occurred in grasslands and in forests, with grass morphotypes of MAC accurately reflecting the burned fuel-type. Despite the lack of local fires around the sites, MAC influx levels reached those reported for local fires. Both MIC and MAC showed strong and highly significant relationships with the MODIS-derived fire parameters, as well as with climatic variation along a latitudinal temperature gradient. Main conclusions: MIC and MAC are suited to quantitatively reconstructing fire number and fire intensity on a regional scale. However, burned area may only be estimated using MAC. Local fires may be identified by using several lines of evidence, e.g. analysis of large particles (>\uc2 600 \uc2\ub5m), magnetic susceptibility and sedimentological data. Our results offer new insights and applications to quantitatively reconstruct fires and to interpret available sedimentary charcoal records

Pollen percentage thresholds of Abies alba based on 13-year annual records of pollen deposition in modified Tauber traps: perspectives of application to fossil situations

Abies alba (fir), a submontane tree from Central European mountains and uplands, is of special interest for palaeoecological and palaeoclimate interpretations due to its sensitivity to air and soil humidity. Its present distribution limit in the uplands of SE Poland is still a matter of debate. In the Holocene fir expanded to Poland very late, but early fir populations are supposed to occur in the Šumava Mts (Czech Republic). The study aims: to estimate pollen thresholds for fir presence/absence in Bohemia (Czech Republic) and Poland on the basis of modified Tauber pollen traps; to use these thresholds for tracing fir presence in two pollen diagrams from Poland (Słone and Bezedna lakes) in the border zone between the Roztocze region (with fir forest stands today) and Polesie (where fir has never played an important role); and to investigate how the percentage presence/absence threshold can be used to trace the occurrence and abundance of fir trees in the Šumava Mts based on the pollen diagrams of Rokytecká slat' and Mrtvý luh. The fir pollen thresholds estimated in terms of PAR (pollen accumulation rates or pollen influx) range from 843 (grains cm−2 year−1) (Roztocze) to 61 (Krkonoše) and 49 (Šumava). Percentage thresholds range from 0.3% in Krkonoše where fir trees are not present within 4 km to 22% in fir-dominated woodland of the Roztocze, providing evidence of strong underrepresentation of fir in the pollen deposition. Application of these percentage thresholds to the Słone and Bezedna pollen diagrams indicates that occurrence of fir in the region is possible from 3.5 cal ky BP onwards, though the evidence is not decisive. In the Šumava, a low representation of fir pollen (1–2%) reflecting presence of scattered fir trees was detected as early as ca. 7.0 cal ky BP