| 1. |
- Abraham, Vojtech, et al.
(författare)
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Patterns in recent and Holocene pollen accumulation rates across Europe - the Pollen Monitoring Programme Database as a tool for vegetation reconstruction
- 2021
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 18:15, s. 4511-4534
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Tidskriftsartikel (refereegranskat)abstract
- The collection of modern, spatially extensive pollen data is important for the interpretation of fossil pollen assemblages and the reconstruction of past vegetation communities in space and time. Modern datasets are readily available for percentage data but lacking for pollen accumulation rates (PARs). Filling this gap has been the motivation of the pollen monitoring network, whose contributors monitored pollen deposition in modified Tauber traps for several years or decades across Europe. Here we present this monitoring dataset consisting of 351 trap locations with a total of 2742 annual samples covering the period from 1981 to 2017. This dataset shows that total PAR is influenced by forest cover and climate parameters, which determine pollen productivity and correlate with latitude. Treeless vegetation produced PAR values of at least 140 grains cm(-2) yr(-1). Tree PAR increased by at least 400 grains cm(-2) yr(-1) with each 10% increase in forest cover. Pollen traps situated beyond 200 km of the distribution of a given tree species still collect occasional pollen grains of that species. The threshold of this long-distance transport differs for individual species and is generally below 60 grains cm(-2) yr(-1). Comparisons between modern and fossil PAR from the same regions show similar values. For temperate taxa, modern analogues for fossil PARs are generally found downslope or southward of the fossil sites. While we do not find modern situations comparable to fossil PAR values of some taxa (e.g. Corylus), CO2 fertilization and land use may cause high modern PARs that are not documented in the fossil record. The modern data are now publicly available in the Neotoma Paleoecology Database and aid interpretations of fossil PAR data.
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| 2. |
- Pearce, Elena A., et al.
(författare)
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Substantial light woodland and open vegetation characterized the temperate forest biome before Homo sapiens
- 2023
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Ingår i: Science Advances. - 2375-2548. ; 9:45
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Tidskriftsartikel (refereegranskat)abstract
- The extent of vegetation openness in past European landscapes is widely debated. In particular, the temperate forest biome has traditionally been defined as dense, closed-canopy forest; however, some argue that large herbivores maintained greater openness or even wood-pasture conditions. Here, we address this question for the Last Interglacial period (129,000–116,000 years ago), before Homo sapiens–linked megafauna declines and anthropogenic landscape transformation. We applied the vegetation reconstruction method REVEALS to 96 Last Interglacial pollen records. We found that light woodland and open vegetation represented, on average, more than 50% cover during this period. The degree of openness was highly variable and only partially linked to climatic factors, indicating the importance of natural disturbance regimes. Our results show that the temperate forest biome was historically heterogeneous rather than uniformly dense, which is consistent with the dependency of much of contemporary European biodiversity on open vegetation and light woodland.
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| 3. |
- Pidek, Irena Agnieszka, et al.
(författare)
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Pollen based quantitative climate reconstructions from the Middle Pleistocene sequences in Lukow and Zdany (E Poland): Species and modern analogues based approach
- 2013
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Ingår i: Review of Palaeobotany and Palynology. - : Elsevier BV. - 0034-6667. ; 192, s. 65-78
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to estimate the range of climate variability during the Ferdynandovian climatostratigraphic unit (MIS 13-15). The studied pollen sequences encompass two interglacials (Ferdynandovian I and II - FI and F II), the glaciation separating them (FI/II), the late glacial of the Sanian I (= Elsterian 1) and the early glacial of the Sanian II (=Elsterian 2) and are correlated with the Cromerian Complex in Western Europe. The modem analogue technique and plant indicator taxa method are applied to two high resolution pollen records (Zdany and Lukow-3a) from E Poland to infer total annual precipitation, mean annual temperature and temperatures of the warmest and the coldest months. The results of the two methods create a coherent picture of climate changes. The succession starts with steppe-tundra and boreal forests, reflecting a cool, late glacial continental climate and develops into widespread Ulmus and Quercus dominated communities, followed by Corylus expansion in warm (at least 18 degrees C in July), oceanic conditions (similar to 800-900 mm annual precipitation) during the first interglacial optimum (F I). The cold, continental climate of the glaciation (FI/II) with annual precipitation of similar to 420 mm and mean January temperature less than -12 degrees C separated the two interglacials. The second interglacial (F II) characterized by Carpinus dominated forests was found to be warm (mean July temperature up to 19 degrees C) but slightly less oceanic, which is consistent with the scarcity of indicators of a warm and humid climate. Principal components analysis (PCA) confirmed the distinctive climatic features of the two interglacials and showed that the cooling F I/II has palynological characteristics Similar to the stadial/interstadial changes within the Sanian I and Sanian II glaciations. (C) 2013 Elsevier B.V. All rights reserved.
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| 4. |
- Pidek, Irena Agnieszka, et al.
(författare)
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Taxon-specific pollen deposition dynamics in a temperate forest zone, SE Poland: the impact of physiological rhythmicity and weather controls
- 2015
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Ingår i: Aerobiologia. - : Springer Science and Business Media LLC. - 0393-5965 .- 1573-3025. ; 31:2, s. 219-238
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Tidskriftsartikel (refereegranskat)abstract
- High and low pollen deposition years in the period 1998-2010 were recorded for ten forest-forming trees in Roztocze (SE Poland) using Tauber-style traps. The coincidence of very high/low pollen deposition years recorded in Tauber traps and aerobiological data obtained by volumetric samplers shows that these phenomena occur simultaneously in different places across vast areas of a tree's distribution range. The natural physiological rhythms displayed in abundance of flowering were considered on the basis of the observed data and published sources. The results obtained from applying Spearman's correlation to pollen accumulation rates from Roztocze and the meteorological parameters confirmed several statistically significant correlations between temperature and summer precipitation prior to pollen emission and a negative correlation with the winter temperature before pollen emission. Air temperature, precipitation, growing season duration (its start and end), winter length and the number of winter days with a daily mean temperature below 0 A degrees C were all considered. The best correlation coefficient results were obtained for the trees most abundant in the vegetation, namely Abies alba, Fagus sylvatica and Pinus sylvestris. Earlier findings on the controlling role of temperature and precipitation during the summer prior to pollen emission were confirmed, and a long period of winter dormancy was stressed as a factor favouring high pollen production. The examples from Roztocze reflected situations when a strong weather signal overrode the natural flowering rhythm. This was observable in the case of P. sylvestris, where pollen production reflected the air temperature of the previous summer or in the case of a mast year, which occurred across the whole distribution range of F. sylvatica in 2006.
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| 5. |
- Pidek, Irena Agnieszka, et al.
(författare)
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Two pollen-based methods of Eemian climate reconstruction employed in the study of the Żabieniec-Jagodne palaeolakes in central Poland
- 2022
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Ingår i: Quaternary International. - : Elsevier BV. - 1040-6182. ; 632, s. 21-35
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to estimate the range of climate variability in Central Poland during the Eemian Interglacial (MIS 5e). High resolution pollen records are available for all seven RPAZs typical of this interglacial in Central Europe. These pollen records were used to estimate total annual precipitation and mean annual temperature, as well as the mean temperatures of the warmest and the coldest months based on the plant indicator method and the modern analogue technique. The reconstructions indicate that the combination of these two methods provides a much clearer insight into the climate changes of the Eemian optimum. The results confirmed no drastic drop in temperature in the Middle Eemian, with high total precipitation in the hazel phase, and that this was followed by a decrease in temperature in the Late Eemian (fir-spruce and pine phases). A drop in precipitation occurred during the youngest part of the Carpinus phase, while coincided with a marked lowering of the water level in lakes and their transformation into peatbogs. The last part of the Eemian is characterized by decreasing temperature, particularly during the coldest month, rising water levels due to a combination of lower evaporation and higher air humidity, and a transition to glacial conditions. Principal Component Analysis found all investigated sites to follow the same pattern of changes. Mean winter temperature, annual temperature and precipitation were found to have a strong positive correlation with the occurrence of thermophilus temperate broadleaved trees (hazel, linden, and ash) typical for the mid-Eemian optimum. These three factors also have a negative correlation with the presence of cold tolerant boreal trees (birch and pine) and open land taxa characteristic of the beginning and end of the interglacial. Mean July temperature was found to be positively correlated with the occurrence of temperate broadleaved trees (oak, ash and elm) typical for early stages of the Eemian and negatively with that of coniferous trees (fir and spruce) characteristic for later stages of the interglacial.
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