0000000000041557
AUTHOR
Normunds Stivrins
showing 35 related works from this author
Fire frequency during the Holocene in central Latvia, northeastern Europe
2021
Fire is today a pan-European issue and is expected to be more salient because of climate and land use changes. Even though natural and anthropogenic fires have shaped forest composition and landscape characteristics since the last glacial retreat from northeastern Europe, fire frequency is an understudied topic. To address this issue, we analysed macroscopic charcoal (>160 μm) from two sediment sequences located in the central and littoral parts of Lake Bricu (central Latvia) revealing the fire frequency during the Holocene. The chronology of the analysed sediment sequences is based on spheroidal fly-ash carbonaceous particles and accelerator mass spectrometry radiocarbon dating. Macroscop…
Sedimentary Ancient DNA (sedaDNA) Reveals Fungal Diversity and Environmental Drivers of Community Changes throughout the Holocene in the Present Bore…
2021
Fungi are ecologically important in several ecosystem processes, yet their community composition, ecophysiological roles, and responses to changing environmental factors in historical sediments are rarely studied. Here we explored ancient fungal DNA from lake Lielais Svētiņu sediment throughout the Holocene (10.5 kyr) using the ITS metabarcoding approach. Our data revealed diverse fungal taxa and smooth community changes during most of the Holocene with rapid changes occurring in the last few millennia. More precisely, plankton parasitic fungi became more diverse from the Late Holocene (2–4 kyr) which could be related to a shift towards a cooler climate. The Latest Holocene (~2 kyr) showed …
Palaeoenvironmental evidence for the impact of the crusades on the local and regional environment of medieval (13th–16th century) northern Latvia, ea…
2015
This paper evaluates the impact of the crusades on the landscape and environment of northern Latvia between the 13th–16th centuries (medieval Livonia). The crusades replaced tribal societies in the eastern Baltic with a religious state (Ordenstaat) run by the military orders and their allies, accompanied by significant social, cultural and economic developments. These changes have previously received little consideration in palaeoenvironmental studies of past land use in the eastern Baltic region, but are fundamental to understanding the development and expansion of a European Christian identity. Sediment cores from Lake Trikāta, located adjacent to a medieval castle and settlement, were s…
Accumulation of metals and changes in composition of freshwater lake organic sediments during the Holocene
2020
Abstract The distribution of metals in the strata of sediments deposited in the freshwater environment formed during the Holocene in the territory of Latvia has been studied rather insufficiently. Considering the large volume of accumulated organic matter in sediments, studies on the content of metallic elements in sediments can help to determine the peculiarities of the metal accumulation process in limnic systems and the biogeochemical cycling of metals. Lake Pilvelis, which is located in the eastern part of Latvia (the northern part of Europe), was selected as the main study site. Lake Pilvelis is a small lake of a glacial origin, and >90% of its depression is filled with organic-rich se…
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…
Peat stratigraphy and changes in peat formation during the Holocene in Latvia
2015
Mires represented by raised bogs, fens, and transitional mires cover approximately 10 % of Latvia. They started to form towards the end of the last glacial period and the beginning of the Holocene under varying geological and palaeoecological conditions. The aim of the study was to evaluate how the results of peat palaeobotanical investigation can reveal changes in the conditions of peat formation and allow a subdivision to be made of the Holocene according to the scheme suggested by the INTIMATE group (Walker et al. 2012). Records from 21 mires have been evaluated to find evidence of changes in mire vegetation and peat formation, and to discover whether these records define boundaries allo…
Holocene fire activity during low-natural flammability periods reveals scale-dependent cultural human-fire relationships in Europe
2018
Abstract Fire is a natural component of global biogeochemical cycles and closely related to changes in human land use. Whereas climate-fuel relationships seem to drive both global and subcontinental fire regimes, human-induced fires are prominent mainly on a local scale. Furthermore, the basic assumption that relates humans and fire regimes in terms of population densities, suggesting that few human-induced fires should occur in periods and areas of low population density, is currently debated. Here, we analyze human-fire relationships throughout the Holocene and discuss how and to what extent human-driven fires affected the landscape transformation in the Central European Lowlands (CEL). W…
Long-Term Consequences of Water Pumping on the Ecosystem Functioning of Lake Sekšu, Latvia
2020
Cultural eutrophication, the process by which pollution due to human activity speeds up natural eutrophication, is a widespread and consequential issue. Here, we present the 85-year history of a small, initially Lobelia&ndash
Investigating the impact of anthropogenic land use on a hemiboreal lake ecosystem using carbon/nitrogen ratios and coupled-optical emission spectrosc…
2019
Anthropogenic impacts on lake ecosystems have increased substantially towards the present. However, the strength and timing in most cases are not evaluated in detail, missing valuable information on the response and recovery of an aquatic system. In this study, we use the sediment total organic carbon/total nitrogen ratio (C/N) and inductively coupled-optical emission spectroscopy (ICP-OES) elements and the available information about the biological processes to explore anthropogenic land use impact on the lake ecosystem. As a case study we selected a hemiboreal lake Trikātas (Latvia, NE Europe). The Pearson correlation was used to statistically test the correlations of all variables. Our r…
Modern pollen and non-pollen palynomorphs along an altitudinal transect in Jammu and Kashmir (Western Himalaya), India
2021
Pollen and non-pollen palynomorphs were analysed from 35 modern moss cushions collected along an altitudinal gradient (2225–2552 m a.s.l.) from the Baramulla District of Jammu and Kashmir State (Western Himalaya), India. The selected sampling altitude is at the elevation of appearance of blue pine (Pinus wallichiana) and West Himalayan spruce or morinda spruce (Picea smithiana). We used cluster analysis and principal component analysis (PCA) to reveal trends and characteristics in the modern pollen and non-pollen palynomorph composition within this zone. Tree taxa mainly correlated positively with the altitudinal gradient, i.e. tree pollen is more abundant at higher altitudes. The presence …
Broadleaf deciduous forest counterbalanced the direct effect of climate on Holocene fire regime in hemiboreal/boreal region (NE Europe)
2017
Abstract Disturbances by fire are essential for the functioning of boreal/hemiboreal forests, but knowledge of long-term fire regime dynamics is limited. We analysed macrocharcoal morphologies and pollen of a sediment record from Lake Lielais Svētiņu (eastern Latvia), and in conjunction with fire traits analysis present the first record of Holocene variability in fire regime, fuel sources and fire types in boreal forests of the Baltic region. We found a phase of moderate to high fire activity during the cool and moist early (mean fire return interval; mFRI of ∼280 years; 11,700–7500 cal yr BP) and the late (mFRI of ∼190 years; 4500–0 cal yr BP) Holocene and low fire activity (mFRI of ∼630 y…
Carbon accumulation rate in a raised bog in Latvia, NE Europe, in relation to climate warming
2018
The carbon accumulation rate (CAR) over the last 180 years was estimated by measuring carbon concentrations in 1-cm layers in a fine-resolution dated and analysed peat sequence in Teiči Bog, Latvia, NE Europe. We used the Granger causality test to examine the temporal (lagged) relationships between the CAR and the historical climate variables. Our results showed that the average CAR was 192 g C m–2 yr–1 during the last 180 years and 169 g C m–2 yr–1 when excluding the acrotelm where decomposition and the stock of carbon are still not in the balance. The Granger causality test showed significant positive temporal associations between the temperature and the CAR, indicating that the temperatu…
Towards understanding the abundance of non-pollen palynomorphs : A comparison of fossil algae, algal pigments and sedaDNA from temperate lake sedimen…
2018
Given the increased interest in non-pollen palynomorphs (microscopic objects other than pollen identified from pollen slides) in palaeoecological studies, it is necessary to seek a deeper understanding of the reliability of these results. We combined quantitative information of algal pigments and sedimentary ancient DNA (sedaDNA) of phylotaxonomical resolution to validate the richness and abundance of fossil algae in the sediment of a small temperate lake. For the first time, fossil and sedaDNA algae data were combined in a composite data-set and used to reconstruct algae turnover rates over the last 14,500 years. This comparison serves as both an example of howfossil algae can be used to a…
Quartz grains reveal sedimentary palaeoenvironment and past storm events: A case study from eastern Baltic
2018
Abstract Sediment record collected from the coastal lake serves as a powerful tool for reconstructing changes in palaeoenvironment and understanding the potential signals of past storminess. In this study, we use several proxies from sediment of the Holocene Thermal Maximum at coastal Lake Lilaste, Latvia. We focus on surface texture of quartz grains from the mineral inorganic fraction as indicators of depositional environments. We then use this as a proxy for potential storm transport and combine with information on granulometry, diatom stratigraphy and chronology to answer the question whether flux of quartz grains in the lake originated from the sea or from the land. Analyses in a binocu…
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…
Environmental drivers and abrupt changes of phytoplankton community in temperate lake Lielais Svētiņu, Eastern Latvia, over the last Post-Glacial per…
2021
Understanding the long-term dynamics of ecological communities on the centuries-to-millennia scale is important for explaining the emergence of present-day biodiversity patterns and for predicting possible future scenarios. Fossil pigments and ancient DNA present in various sedimentary deposits can be analysed to study long-term changes in ecological communities. We analysed recent compilations of data, including fossil pigments, microfossils, and molecular inventories from the sedimentary archives, to understand the impact of gradual versus abrupt climate changes on the ecosystem status of a regional model lake over the last ~14.5 kyr. Such long and complete paleo-archives are scarce in No…
Current Wildland Fire Patterns and Challenges in Europe: A Synthesis of National Perspectives
2021
Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by natio…
Drivers of change and ecosystem status in a temperate lake over the last Post-Glacial period from 14.5 kyr
2020
AbstractUnderstanding the long-term dynamics of ecological communities on the centuries-to-millennia scale is important for explaining present-day biodiversity patterns. Placing these patterns in a historical context could yield reliable tools for predicting possible future scenarios. Paleoarchives of macro+ and micro-fossil remains, and most importantly biomarkers such as fossil pigments and ancient DNA present in various sedimentary deposits, allow long term changes in ecological communities to be analysed. We use recent compilations of data including fossil pigments, metabarcoding of sedimentary ancient DNA and microfossils together with data analysis to understand the impact of gradual …
Food availability and temperature optima shaped functional composition of chironomid assemblages during the Late Glacial–Holocene transition in North…
2021
Abstract Non-biting midges (Chironomidae) are the most diverse and abundant invertebrate group in boreal lakes and are strongly responsive to climate change, thus they are a valuable palaeoecological proxy for studying aquatic biodiversity response in the face of climate change. Here, we aim to decipher the influence of climate-induced changes on temporal patterns in chironomid assemblages. We apply a novel approach combining traditional taxon-based analysis and species-trait framework to subfossil chironomid assemblages in a sediment core covering the Late Glacial–Holocene transition in Northern Europe. We produce pollen-based July and January temperature reconstructions to characterize pa…
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…
Large herbivore population and vegetation dynamics 14,600–8300 years ago in central Latvia, northeastern Europe
2019
Abstract This study seeks to explain how the large herbivore (large vertebrate, megafauna – terrestrial taxa with adults > 45 kg) population density changed during abrupt postglacial climate and environmental change. The Lateglacial and Early Holocene (14,600–8300 years ago) were represented by various environmental and climate changes and a transition from a cold to a warm climate, with subsequent changes in flora and fauna. Using Lake Āraisi as a case study (Latvia, northeastern Europe), local to regional vegetation was reconstructed by analyzing plant macroremains and pollen from the lake sediment profile. Here, we present the first dung fungus spore-based qualitative reconstruction of l…
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…
sj-docx-1-asw-10.1177_11786221211028185 – Supplemental material for Current Wildland Fire Patterns and Challenges in Europe: A Synthesis of National …
2021
Supplemental material, sj-docx-1-asw-10.1177_11786221211028185 for Current Wildland Fire Patterns and Challenges in Europe: A Synthesis of National Perspectives by Nieves Fernandez-Anez, Andrey Krasovskiy, Mortimer Müller, Harald Vacik, Jan Baetens, Emira Hukić, Marijana Kapovic Solomun, Irena Atanassova, Maria Glushkova, Igor Bogunović, Hana Fajković, Hakan Djuma, George Boustras, Martin Adámek, Miloslav Devetter, Michaela Hrabalikova, Dalibor Huska, Petra Martínez Barroso, Magdalena Daria Vaverková, David Zumr, Kalev Jõgiste, Marek Metslaid, Kajar Koster, Egle Köster, Jukka Pumpanen, Caius Ribeiro-Kumara, Simone Di Prima, Amandine Pastor, Cornelia Rumpel, Manuel Seeger, Ioannis Daliakopou…
Holocene fires in the central European lowlands and the role of humans
2018
International audience; A major debate concerns the questions of when and to what extent humans affected regional landscapes, especially land cover and associated geomorphological dynamics, significantly beyond natural variability. Fire is both, a natural component of many climate zones and ecosystems around the globe and also closely related to human land cover change. Humans clearly affected natural fire regimes and landscapes in the most recent centuries, acting as prime ignition triggers and later fire suppressors, while Holocene trends in sedimentary charcoal have been mainly associated with climatic factors and partly with Neolithic land cover change. However, little is known since wh…
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
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
Modern pollen and non-pollen palynomorphs along an altitudinal transect in Jammu and Kashmir (Western Himalaya), India
2021
Pollen and non-pollen palynomorphs were analysed from 35 modern moss cushions collected along an altitudinal gradient (2225–2552 m a.s.l.) from the Baramulla District of Jammu and Kashmir State (Western Himalaya), India. The selected sampling altitude is at the elevation of appearance of blue pine (Pinus wallichiana) and West Himalayan spruce or morinda spruce (Picea smithiana). We used cluster analysis and principal component analysis (PCA) to reveal trends and characteristics in the modern pollen and non-pollen palynomorph composition within this zone. Tree taxa mainly correlated positively with the altitudinal gradient, i.e. tree pollen is more abundant at higher altitudes. The presence …
Data for: Large herbivore population and vegetation dynamics 14600–8300 years ago in central Latvia, northeastern Europe
2020
Raw data of pollen and plant macrofossils