0000000000413508
AUTHOR
Heikki Seppä
showing 17 related works from this author
ESM_Figure_S1_The_results_of_the_SiZer_analyses_of_Alnus_pollen_curves_in_selected_sites_in_Poland – Supplemental material for Abrupt Alnus populatio…
2019
Supplemental material, ESM_Figure_S1_The_results_of_the_SiZer_analyses_of_Alnus_pollen_curves_in_selected_sites_in_Poland for Abrupt Alnus population decline at the end of the first millennium CE in Europe – The event ecology, possible causes and implications by Małgorzata Latałowa, Joanna Święta-Musznicka, Michał Słowiński, Anna Pędziszewska, Agnieszka M NoryŚkiewicz, Marcelina Zimny, Milena Obremska, Florian Ott, Normunds Stivrins, Leena Pasanen, Liisa Ilvonen, Lasse Holmström and Heikki Seppä in The Holocene
The Eurasian Modern Pollen Database (EMPD), version 2
2020
The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to…
Holocene land-cover reconstructions for studies on land cover-climate feedbacks
2010
The major objectives of this paper are: (1) to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC) developed during the last ten years, (2) to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites), to infer long-term records of past land-cover from pollen data, (3) to present a new project (LANDCLIM: LAND cover – CLIMate interactions in NW Europe during the Holocene) currently underway, and show preliminary results of REVEALS reconstructions of the regional land-cover in the Czech Republic for five selected time windows of the Holocene…
Regional climate model simulations for Europe at 6 and 0.2 k BP: sensitivity to changes in anthropogenic deforestation
2014
International audience; This study aims to evaluate the direct effects of anthropogenic deforestation on simulated climate at two contrasting periods in the Holocene, ∼ 6 and ∼ 0.2 k BP in Eu-rope. We apply the Rossby Centre regional climate model RCA3, a regional climate model with 50 km spatial resolution, for both time periods, considering three alternative descriptions of the past vegetation: (i) potential natural vegetation (V) simulated by the dynamic vegetation model LPJ-GUESS, (ii) potential vegetation with anthro-pogenic land use (deforestation) from the HYDE3.1 (History Database of the Global Environment) scenario (V + H3.1), and (iii) potential vegetation with anthropogenic land …
From microbial eukaryotes to metazoan vertebrates: Wide spectrum paleo-diversity in sedimentary ancient DNA over the last ~14,500 years
2018
Most studies that utilize ancient DNA have focused on specific groups of organisms or even single species. Instead, the whole biodiversity of eukaryotes can be described using universal phylogenetic marker genes found within well-preserved sediment cores that cover the post-glacial period. Sedimentary ancient DNA samples from Lake Lielais Svētiņu, eastern Latvia, at a core depth of 1,050 cm in ~150 year intervals were used to determine phylotaxonomy in domain Eukaryota. Phylotaxonomic affiliation of >1,200 eukaryotic phylotypes revealed high richness in all major eukaryotic groups-Alveolata, Stramenopiles, Cercozoa, Chlorophyta, Charophyta, Nucletmycea, and Holozoa. The share of organisms t…
Multiscale variation in drought controlled historical forest fire activity in the boreal forests of eastern Fennoscandia
2017
Forest fires are a key disturbance in boreal forests, and characteristics of fire regimes are among the most important factors explaining the variation in forest structure and species composition. The occurrence of fire is connected with climate, but earlier, mostly local-scale studies in the northern European boreal forests have provided little insight into fire-climate relationship before the modern fire suppression period. Here, we compiled annually resolved fire history, temperature, and precipitation reconstructions from eastern Fennoscandia from the mid-16th century to the end of the 19th century, a period of strong human influence on fires. We used synchrony of fires over the network…
Abrupt Alnus population decline at the end of the first millennium CE in Europe - The event ecology, possible causes and implications
2019
The study, based on the examination of 70 published and unpublished pollen profiles from Poland and supplementary data from the surrounding regions, shows that an abrupt, episodic Alnus population decline at the end of the first millennium CE was a much more widespread event than has been previously reported, spanning large areas of the temperate and boreal zones in Europe. The data from Poland suggest that the decline was roughly synchronous and most likely occurred between the 9th and 10th centuries, with strong indications for the 10th century. The pollen data indicate that human impacts were not a major factor in the event. Instead, we hypothesize that one or a series of abrupt climatic…
Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe
2019
Fire is a major disturbance agent in the boreal forest, influencing many current and future ecosystem conditions and services. Surprisingly few studies have attempted to improve the accuracy of fire-event reconstructions even though the estimates of the occurrence of past fires may be biased, influencing the reliability of the models employing those data (e.g. C stock, cycle). This study aimed to demonstrate how three types of fire proxies – fire scars from tree rings, sedimentary charcoal and, for the first time in this context, fungal spores of Neurospora – can be integrated to achieve a better understanding of past fire dynamics. By studying charcoal and Neurospora from sediment cores f…
Sub-kelvin current amplifier using DC-SQUID
2000
Abstract We have set up a system where a low-noise DC-SQUID is used as a current amplifier. The SQUID output is read using a wide band electronics unit based on the noise cancellation scheme. The SQUID has been installed in a compact Nanoway PDR50 dilution refrigerator, and superconducting transitions of Ti/Au thermometer strips for X-ray calorimeter applications have been measured. We can operate at 100 mK using a SQUID with Pd shunt resistors. Noise and bandwidth results of the setup are presented.
Latalowa_M_et_al._ESM_Table_S2 – Supplemental material for Abrupt Alnus population decline at the end of the first millennium CE in Europe – The even…
2019
Supplemental material, Latalowa_M_et_al._ESM_Table_S2 for Abrupt Alnus population decline at the end of the first millennium CE in Europe – The event ecology, possible causes and implications by Małgorzata Latałowa, Joanna Święta-Musznicka, Michał Słowiński, Anna Pędziszewska, Agnieszka M NoryŚkiewicz, Marcelina Zimny, Milena Obremska, Florian Ott, Normunds Stivrins, Leena Pasanen, Liisa Ilvonen, Lasse Holmström and Heikki Seppä in The Holocene
Supplementary_material_2 – Supplemental material for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest …
2019
Supplemental material, Supplementary_material_2 for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe by Normunds Stivrins, Tuomas Aakala, Liisa Ilvonen, Leena Pasanen, Timo Kuuluvainen, Harri Vasander, Mariusz Gałka, Helena R Disbrey, Janis Liepins, Lasse Holmström and Heikki Seppä in The Holocene
Supplementary_material_1 – Supplemental material for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest …
2019
Supplemental material, Supplementary_material_1 for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe by Normunds Stivrins, Tuomas Aakala, Liisa Ilvonen, Leena Pasanen, Timo Kuuluvainen, Harri Vasander, Mariusz Gałka, Helena R Disbrey, Janis Liepins, Lasse Holmström and Heikki Seppä in The Holocene
Latalowa_M_et_al._ESM_Table_S1 – Supplemental material for Abrupt Alnus population decline at the end of the first millennium CE in Europe – The even…
2019
Supplemental material, Latalowa_M_et_al._ESM_Table_S1 for Abrupt Alnus population decline at the end of the first millennium CE in Europe – The event ecology, possible causes and implications by Małgorzata Latałowa, Joanna Święta-Musznicka, Michał Słowiński, Anna Pędziszewska, Agnieszka M NoryŚkiewicz, Marcelina Zimny, Milena Obremska, Florian Ott, Normunds Stivrins, Leena Pasanen, Liisa Ilvonen, Lasse Holmström and Heikki Seppä in The Holocene
Supplementary_material_2 – Supplemental material for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest …
2019
Supplemental material, Supplementary_material_2 for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe by Normunds Stivrins, Tuomas Aakala, Liisa Ilvonen, Leena Pasanen, Timo Kuuluvainen, Harri Vasander, Mariusz Gałka, Helena R Disbrey, Janis Liepins, Lasse Holmström and Heikki Seppä in The Holocene
Supplementary_material_1 – Supplemental material for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest …
2019
Supplemental material, Supplementary_material_1 for Integrating fire-scar, charcoal and fungal spore data to study fire events in the boreal forest of northern Europe by Normunds Stivrins, Tuomas Aakala, Liisa Ilvonen, Leena Pasanen, Timo Kuuluvainen, Harri Vasander, Mariusz Gałka, Helena R Disbrey, Janis Liepins, Lasse Holmström and Heikki Seppä in The Holocene
Latalowa_M_et_al._ESM_Table_S3 – Supplemental material for Abrupt Alnus population decline at the end of the first millennium CE in Europe – The even…
2019
Supplemental material, Latalowa_M_et_al._ESM_Table_S3 for Abrupt Alnus population decline at the end of the first millennium CE in Europe – The event ecology, possible causes and implications by Małgorzata Latałowa, Joanna Święta-Musznicka, Michał Słowiński, Anna Pędziszewska, Agnieszka M NoryŚkiewicz, Marcelina Zimny, Milena Obremska, Florian Ott, Normunds Stivrins, Leena Pasanen, Liisa Ilvonen, Lasse Holmström and Heikki Seppä in The Holocene
Quantitative reconstruction of hydroclimate variability over the last 200 kyr in the West Mediterranean
2022
The data show the quantitative annual, winter and summer precipitation reconstructions (mm/yr) from southern Iberian Peninsula for the last ~200,000 years (Camuera et al., 2022), based on the previously published fossil pollen data from the Padul-15-05 lake sediment record (Ramos-Román et al., 2018a, b; Camuera et al., 2019, 2021). The Padul-15-05 record, located in southern Spain (37º00'39''N, 3º36'14''W, 726 masl), was retrieved during summer 2015 from the current edge of the lake using a Rolatec RL-48-L hydraulic percussion coring machine. The quantitative precipitation reconstructions were performed using the performance statistics of the Weighted Averaging-Partial Least Squares (WA-PLS…