www.epicentrs.lv - News

Long-Term Stability of Coastal Forests Revealed in New Study

Fri, 06 Jun 2025 19:53:00 +0000

A new scientific article from our team, published in the journal Quaternary, explores how Latvia’s coastal vegetation developed and responded to climate and human activity over the last 10,000 years. The research reveals that Latvia’s coastal forests have remained remarkably stable for thousands of years, particularly during the middle Holocene when broadleaved trees like oak, lime, and hazel dominated the landscape in other locations. The findings are based on sediment core analysis from a site near the Gulf of Riga, using pollen and sediment data to track how vegetation and land use have changed since the last Ice Age.

Why does this matter?

The long-term resilience of coastal forests under past climate shifts shows that these ecosystems are naturally stable, until human pressure increases. This study provides a valuable reference for what "natural" forest conditions look like, helping guide conservation and restoration in the coastal zone of Latvia and beyond.

Read the full article: Influence of geological and soil factors on pine, birch, and alder stability during the Holocene climate change in central Latvia, Northeastern Europe.

New Research on Peatland History in Latvia

Fri, 06 Jun 2025 19:21:00 +0000

The Lake and Peatland Research Centre is proud to share the results of a new scientific article published in the journal Catena, titled "Climate change impact on peatland dynamics during the Holocene in Latvia". This study brings together long-term data from 26 peatlands across Latvia (Fig.1) to understand how these unique ecosystems have formed and evolved over the past 11,000 years.

Figure 1: Peatland study sites across Latvia. Each red circle marks a location where data were collected.

What did we find?

Peatlands started forming in Latvia over 11,000 years ago, beginning as fens - mires rich in nutrients fed by groundwater. Later, many of these fens transformed into bogs, which rely only on rainfall and are more acidic and nutrient-poor. During the Middle Holocene (around 8,200–4,200 years ago), peatland growth slowed down due to a warmer and drier climate - a period similar to what we may face again due to modern climate change. On the other hand, cooler and wetter periods - especially the Early and Late Holocene - favoured peat formation. These conditions allowed peatlands to store more carbon, highlighting their role as natural climate regulators. Our results show that Latvian raised bogs have stored up to 194 grams of carbon per square metre per year in recent millennia, confirming their importance as carbon sinks.

Why does this matter today?

With the climate getting warmer and drier, especially in summer, there's a real risk that peatlands will stop accumulating peat and carbon - possibly even turning from carbon sinks into carbon sources. This makes peatland protection and restoration more important than ever.

Read the full article here: DOI: 10.1016/j.catena.2025.108965

Rising Temperatures May Reduce Carbon Storage in Wetlands

Sat, 23 Nov 2024 12:47:00 +0000

A new global study suggests that rising temperatures may reduce the amount of carbon stored in wetlands and bogs. This conclusion was reached by an international team of 110 scientists who studied the decomposition rates of green and rooibos tea in 180 wetlands across 28 countries to evaluate the carbon storage capacity of bogs (Figure 1).

Figure 1. Experimental sites included in the study.

The study, published in the prestigious journal Environmental Science and Technology, included contributions from scientists Ilze Ozola, Ieva Grudzinska-Elsberga, and Normunds Stivrins from the Lake and Peatland Research Centre. In Latvian peatlands, two types of tea bags were buried at a depth of 15 cm, and the changes in organic matter volume were measured over a three-year period. The results were then used to calculate carbon retention trends (Figure 2), which complemented the global data set from other wetlands and peatlands.

Figure 2. Tea bag experiment in Kaigu peatland (fen peat conditions).

Green tea bags contain organic material that decomposes quickly, whereas rooibos tea decomposes more slowly. The use of tea bags provides a simple and standardized method to determine how climate, habitat, and soil type influence the rate of carbon decomposition in wetlands. The differences between these two types of tea allowed researchers to gain a more comprehensive understanding of the carbon storage capacity of wetlands.

Although the use of tea bags in science is a well-tested and validated method for determining carbon release from soil into the atmosphere, this is the first time that tea bags have been used for such a large-scale and long-term study in wetlands.

The results indicate that, overall, higher temperatures accelerated the decomposition of organic matter, reducing carbon retention in soil and peat. It was found that freshwater wetlands and tidal marshes retained the most tea mass, indicating a greater potential for carbon storage and retention in these ecosystems. The data from Kaigu peatland suggest that, while newly accumulated organic material in fen peat may be sensitive to rising temperatures, this ecosystem has a higher carbon storage potential compared to other types of wetlands.

*Article:

Climate Effects on Belowground Tea Litter Decomposition Depend on Ecosystem and Organic Matter Types in Global Wetlands. Environmental Science & Technology.

There are less fen peatlands in Latvia than we considered

Thu, 14 Mar 2024 18:20:00 +0000

Without doubt, Latvia's peatlands play an important role in both meeting the country's climate goals and preserving natural diversity. According to the Latvian Centre of Environment, Geology and Meteorology, approximately 10-15% of Latvia's territory is covered by peatlands, which are more precisely defined as deposits. From a current Latvian geological terminology, a peat deposit is defined as an area of at least 2 ha with a peat thickness of at least 30 cm. The 2023 report of the State Audit Office of the Republic of Latvia on "Management of mineral resources in Latvia" states that the lack of data makes it difficult or impossible to fully develop sustainable policies regarding natural recourses.

The same lack of data makes it difficult to predict the extent of peatlands and their potential contribution to climate change mitigation, as only about 60% of peat deposits are identified, and this figure is based on peat stock data obtained from the period 1960 to 1980. It is assumed that in Europe, Latvia ranks 5th in greenhouse gas (GHG) emissions from drained peatland areas.

It should be noted that with lower humidity and higher oxygen content in peat and peat soils, decomposition of organic compounds is faster. Consequently, new inventories of peatlands and peat deposits, as well as the identification of drained areas, can further contribute to sustainable policymaking. It is widely believed that about half of all peatlands in Latvia are fens (wet grass-sedges dominated) and the other half are raised bogs (Sphagnum moss dominated), but is this really the case? Although the Nature Counting project has provided additional information on bog areas, the project in question only surveyed habitats of European Union importance, which does not include an update on the situation of fens.

Given the lack of information on fens, Davis Matskins (student from the University of Latvia supervised by the Prof. Normunds Stivrins) look closer on this topic. He qualitatively assessed the distribution and changes of fens in one of the largest municipalities of Latvia – Ogre. After a feasibility study, 20 fen-type peat deposits were randomly selected and surveyed in the field to determine the type, thickness and characteristics of the peat they contain.

As a result, out of the 20 sites surveyed, only 5 corresponded to a fen peat deposit (with a 30 cm peat layer) and only 1 of these corresponded to a fen peatland also in terms of vegetation and moisture regime. These first results indicated unexpected situation – 75 % of fen peatlands are not anymore there! If similar situation is applicable to the whole territory of Latvia, then the actual numbers are staggering and so off that the official reports to the European Union must be changed according to the real fen distribution and associated GHG, and land use.

It was found that at all five actual fen peatland sites the upper 10 cm contained a lower proportion of organic material than the deeper sediments. These results indicate a potential peat mineralisation process and a more pronounced peat decomposition closer to the surface. Existing fen peat deposits are subject to intensive mineralisation, which means that existing peat layers are decomposing, resulting in GHG emissions and the disappearance of fen peat deposits.

The main conclusion from this study is that there are significantly fewer fen peatlands, as indicated, for example, in the Latvian Centre of Environment, Geology and Meteorology database, and a more detailed analysis of their distribution is needed through inspection and verification in the field at the national level.

Prepared by Normunds Stivrins

read full scientific article: Declining extent of fen peat deposits over the past 50 years in Ogre Municipality, central Latvia

Microplastics in Latvian lakes

Thu, 14 Mar 2024 17:52:00 +0000

An international team of researchers (including members of the Lake and Peatland Research Centre) studying the sediments of three Latvian lakes (Usma, Sekši, Pinku) has concluded that the presence of microplastic particles in a particular sediment layer is not indicative of the time when it was produced or released into the environment, as microplastic particles tend to move deeper into the sediment. For example, biodegradable plastics such as polylactide (PLA) were only commercially produced in the 1990s, but can be found in Latvian lake sediments even in layers dating back to the 18th-20th centuries (1733-1813 in Lake Pinki, 1900-1925 in Lake Usma).

The publication of the study in Science Advances is available at: https://www.science.org/doi/10.1126/sciadv.adi8136

LPRC becomes a member of the Latvian National Peat Society

Thu, 29 Dec 2022 07:34:00 +0000

In November 2022, the Lakes and Peatland Research Centre (LPRC) became a member of the Latvian National Peat Society (LNKB). The objectives of the LNKB are to promote peat as a slowly renewable natural resource in the EU Green Deal, which includes close cooperation with Latvian scientists and research, modernisation of the peat sector and reduction of emissions, local consumption of peat and development of innovative peat products with added value. It is important to note that the LNKB has just become the official Latvian representative of the International Peatland Society (IPS).

Epicentrs now available on youtube

Mon, 27 Jun 2022 09:05:00 +0000

You can follow us now on youtube (Ezeru un Purvu Izpētes Centrs (epicentrs.lv)) where the content will be available both in Latvian and English.

Black Death Mortality not as Widespread as Long Thought

Tue, 18 Jan 2022 08:30:00 +0000

Pollen data from 19 modern European countries reveals that although the Black Death had a devastating impact in some regions, parts of Europe experienced negligible or no impact at all.

A new study in the journal Nature Ecology and Evolution uses pollen data to evaluate the second plague pandemic’s mortality at a regional scale across Europe. Results show that the impacts of the Black Death varied substantially from region to region and demonstrate the importance of cross-disciplinary approaches for understanding past – and present – pandemics.

The Black Death, which plagued Europe, West Asia and North Africa from 1347-1352, is the most infamous pandemic in history. Historians have estimated that up to 50% of Europe’s population died during the pandemic and credit the Black Death with transforming religious and political structures, even precipitating major cultural and economic transformations such as the Renaissance. Although ancient DNA research has identified Yersinia pestis as the Black Death’s causative agent and even traced its evolution across millennia, data on the plague’s demographic impacts is still underexplored and little understood.

Now, a new study in Nature Ecology and Evolution demonstrates that the Black Death’s mortality in Europe was not as universal or as widespread as long thought. An international team of researchers, including Normunds Stivrins and Nauris Jasiunas from the University of Latvia and other researchers from the whole Europe, led by the Palaeo-Science and History group at the Max Planck Institute for the Science of Human History, analyzed pollen samples from 261 sites in 19 modern-day European countries to determine how landscapes and agricultural activity changed between 1250 and 1450 CE - roughly 100 years before to 100 years after the pandemic. Their analysis supports the devastation experienced by some European regions, but also shows that the Black Death did not impact all regions equally.

Landscapes tell a surprising story

Palynology, or the study of fossil plant spores and pollen, is a powerful tool for uncovering the demographic impacts of the Black Death. This is because human pressures on the landscape in pre-industrial times, such as farming or clearing native plants for building, were heavily dependent on the availability of rural workers. Using a new approach called Big-data paleoecology (BDP), the researchers analyzed 1,634 pollen samples from sites all over Europe to see which plants were growing in which quantities, and thereby determine whether agricultural activities in each region continued or halted, or if wild plants regrew while human pressure is reduced.

Their results show that the Black Death’s mortality varied widely, with some areas suffering the devastation the pandemic has become known for and others experiencing a much lighter touch. Sharp agricultural declines in Scandinavia, France, southwestern Germany, Greece and central Italy support the high mortality rates attested to in medieval sources. Meanwhile many regions, including much of Central and Eastern Europe and parts of Western Europe including Ireland and Iberia, show evidence for continuity or uninterrupted growth.

“The significant variability in mortality that our BDP approach identifies remains to be explained, but local cultural, demographic, economic, environmental and societal contexts would have influenced Y. pestis prevalence, morbidity and mortality,” says Alessia Masi from the MPI SHH and La Sapienza University in Rome.

No single model of the pandemic

One reason these results come as a surprise is that many of the quantitative sources that have been used to construct Black Death case studies come from urban areas, which, despite their ability to collect information and keep records, were also characterized by crowding and poor sanitation. However, in the mid 14^th century, upwards of 75% of the population of every European region was rural. The current study shows that, to understand the mortality of a particular region, data must be reconstructed from local sources, including BDP as method for measuring change in cultural landscapes.

“There is no single model of ‘the pandemic’ or a ‘plague outbreak’ that can be applied to any place at any time regardless of the context,” says Adam Izdebski, the leader of the Palaeo-Science and History group at the MPI SHH. “Pandemics are complex phenomena that have regional, local histories. We have seen this with COVID-19, now we have now shown it for the Black Death.”

The differences in the Black Death’s mortality across Europe demonstrates that the plague was a dynamic disease, with cultural, ecological, economic and climatic factors mediating its dissemination and impact. Moving forward, the researchers hope that more studies will use palaeoecological data to understand how these variables interact to shape past – and present – pandemics.

Title: Palaeoecological Data indicates land-use changes across Europe linked to spatial heterogeneity in mortality during the Black Death pandemic

Authors: Izdebski A., Guzowski P., Poniat R., Masci L., Palli J., Vignola C., Bauch M., Cocozza C., Fernandes R., Ljungqvist F.C., Newfield T., Seim A., Abel-Schaad D., Alba-Sánchez F., Björkman L., Brauer A., Brown A., Czerwiński S., Ejarque A., Fiłoc M., Florenzano A., Fredh E.D., Fyfe R., Jasiunas N., Kołaczek P., Kouli K.,1, Kozáková R., Kupryjanowicz M., Lagerås P., Lamentowicz M., Lindbladh M., López-Sáez J.A., Luelmo-Lautenschlaeger R., Marcisz K., Mazier F., Mensing S., Mercuri A.M., Milecka K., Miras Y., Noryśkiewicz A. M., Novenko E., Obremska M., Panajiotidis, S., Papadopoulou, M.L., Pędziszewska A., Pérez-Díaz S., Piovesan G., Pluskowski A., Pokorny P., Poska A., Reitalu T., Rösch M., Sadori L., Sá Ferreira C., Sebag D., Słowiński M., Stančikaitė M., Stivrins N., Tunno I., Veski S., Wacnik A., Masi A.

Publication: Nature Ecology & Evolution

DOI: https://doi.org/10.1038/s41559-021-01652-4

Web: https://www.nature.com/articles/s41559-021-01652-4

Photo credit: Hans Sell, Michelle O’Reilly, Adam Izdebski

Legislation scheme on the extraction of mineral resources

Thu, 01 Feb 2018 12:04:00 +0000

A short time ago I was involved in a project on EU legislation on the extraction of mineral resources. My section was on the laws and regulations in Latvia. Unfortunately, the European Commission has not yet given its approval to publish the report of the study and, consequently, for the time being, I can’t publish also my report for this study. However, I will share a small part of the results – the legislation scheme on the extraction of mineral resources.

It is not easy to navigate in the legislation jungles in Latvia. Let this scheme serve as a landmark for those brave who are ready to take a risk and DIG!

Please download scheme here.

TeaComposition H2O initiative

Mon, 29 Jan 2018 11:08:00 +0000

Lake and Peatland Research Centre is the only organization from Latvia taking part in the TeaComposition H2O initiative that aims to tease apart the factors that make some ecosystems greenhouse gas emitters while others carbon-sequestering ecosystems. TeaComposition H2O is a global-scale analysis of litter decomposition within wetland ecosystems using household tea bags or Tea Decomposition by monitoring how fast tea bags buried in the soil decompose. There are over 350 sites around the world located in 35 countries and the project will last for three years. For more information read later or see http://www.bluecarbonlab.org/teacomposition-h2o/

map from:
http://www.bluecarbonlab.org/teacomposition-h2o/

Post author: N. Stivrins