Estonian Environmental Research Center

Tallinn, Estonia

Estonian Environmental Research Center

Tallinn, Estonia
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Iital A.,Tallinn University of Technology | Pachel K.,Tallinn University of Technology | Pachel K.,Estonian Environmental Research Center | Loigu E.,Tallinn University of Technology | And 2 more authors.
Journal of Environmental Monitoring | Year: 2010

The aim of the study was assessment of changes in nutrient concentrations in Estonian rivers as a response to improved wastewater treatment and substantial reductions in the use of fertilisers and number of livestock during the past 15-20 years. A Mann-Kendall test and flow adjusted technique to assess recent trends have been used. Statistical analysis covered time series of 53 sampling sites on 40 rivers and streams in different hydro-geographical regions and varying human pressures. The results indicate a statistically significant downward trend in nitrogen concentration in 18 sampling stations during the studied period; only very few showed an upward trend. These decreases in total nitrogen (TN) relate mainly to (i) substantial reductions in the use of fertilisers, (ii) decreased area of agricultural land, (iii) decreased point source load and (iv) increased self-purification capacity of soil-water systems. The concentration of phosphorus decreased only in 13 locations, despite of efforts to improve the efficiency of wastewater treatment. Moreover, in seven locations the concentration of phosphorus was increasing. This increase in total phosphorus (TP) probably relates to the low treatment efficiency of small wastewater treatment facilities as well as to the raised ground water table due to insufficient maintenance of drainage systems that favour transport of soil P to water bodies. Accordingly, the ratio of nitrogen and phosphorus had both decreasing and increasing trends. © 2010 The Royal Society of Chemistry.

Keis M.,University of Tartu | Remm J.,University of Tartu | Ho S.Y.W.,University of Sydney | Davison J.,University of Tartu | And 8 more authors.
Journal of Biogeography | Year: 2013

Aim: Using sequences of complete mitochondrial genomes, our aims were: (1) to investigate the matrilineal phylogeographical structure, migration patterns and lineage coalescence times in a large, continuous population of brown bears (Ursus arctos); and (2) to develop a novel spatial genetic method to identify migration corridors and barriers. Location: North-western Eurasia: from eastern European Russia to the Baltic Sea. Methods: We sequenced the complete mitochondrial genomes of 95 brown bears. The phylogeographical resolution of complete genomes was compared to that derived from subsets of the genome, including the most commonly used shorter sequences. We conducted network and Bayesian phylogeographical analyses and developed a novel, spatially explicit, individual-based approach (called DResD) for identifying migration corridors and barriers. Results: Analysis of mitogenome sequences revealed five haplogroups, specific to particular geographical areas, exhibiting far greater resolving power than shorter sequences. Estimated coalescence times for the haplogroups ranged from 7.7 to 15.2 ka, suggesting that their divergence took place after the last glaciation. We found several migration trends, including a large westward migration from eastern European Russia towards Finland. We also found evidence of a potential barrier and a migration corridor in the south-west of the study area. Main conclusions: The use of complete mitochondrial genomes from a brown bear population in north-western Eurasia allowed us to identify phylogeographical structure, signatures of demographic history and spatial processes that had not previously been detected using shorter sequences. These findings have implications for studies on other species and populations, especially those exhibiting low mtDNA diversity. The relatively recent divergence estimates for haplogroups highlight the significance not only of the last glaciation but also of climatic fluctuations during the post-glacial period for the divergence of mammal populations in Europe. Our spatial genetic method represents a new tool for the analysis of genetic data in a geographical context and is applicable to any data that yield genetic distance matrices, including microsatellites, amplified fragment length polymorphisms (AFLPs) and single-nucleotide polymorphisms (SNPs). © 2012 Blackwell Publishing Ltd.

Roots O.O.,Estonian Environmental Research Center | Roose A.,University of Tartu | Eerme K.,Tartu Observatory
International Journal of Remote Sensing | Year: 2011

The Fifth National Communication Under the Framework Convention on Climate Change covered the policies and activities in Estonia of the period 2006-2009. Climate change and air pollution cause significant damage, especially to various materials. Worldwide, 387 objects belong to the United Nations Educational, Scientific and Cultural Organization (UNESCO) World heritage list, including the Old Town of Tallinn. The International Cooperative Programme on Effects on Materials, including Historic and Cultural Monuments (ICPMaterials) is an ongoing research programme in the framework of which air pollution and the effect of climate on the corrosion of various natural and synthetic materials, including historical and cultural monuments, is studied. So far, the studies have shown that even though air pollution has continuously declined in Estonia, no significant reduction in corrosion has been noticed on the displayed limestone sample plates at the Lahemaa air monitoring station. On the contrary, in 2005-2006, the corrosion loss of limestone was greater compared with that in 1987-2003. It could be explained partly by changing environmental conditions but another possible explanation is that the Portland limestone as a stone material has a different quality. © 2011 Taylor & Francis.

Roots O.,Estonian Environmental Research Center | Lukki T.,Tallinn University
Proceedings of the Estonian Academy of Sciences | Year: 2016

This article deals with the analytical results of environmental monitoring and screening performed on the identification and sources of hazardous substances in the Estonian aquatic environment. The concentrations of hazardous substances have been studied at different sampling sites and matrices. A total of 130 hazardous substances from 12 groups of substances were investigated in the framework of the BaltActHaz project. The findings suggest that the status of the majority of Estonian surface water bodies is good: the concentrations of hazardous substances measured remained below the analytical detection limit in most of the samples analysed. The contents of only some phthalates, e.g. diisobutylphthalate, di-(2-ethylhexyl)-phthalate, and dimethylphtalate, exceeded the analytical detection limit. Mono-and dibutyltin and benzene were found from some water samples in rivers. However, the content of some heavy metals as well as mono-and dibasic phenols in the surface water/wastewater can still reach delicate levels, in particular in the Estonian oil shale region. The concentrations of organotin compounds are high in the areas of ports and shipyards. The assessment of the water contamination by hazardous substances indicates the relevance of the continuation of the monitoring due to its crucial role for an appropriate decision-making in the protection of the aquatic environment of Estonia. Continued monitoring is necessary to mitigate the exposure and to protect the living resources. © 2016 Authors.

Tammeleht E.,University of Tartu | Remm J.,University of Tartu | Korsten M.,University of Tartu | Davison J.,University of Tartu | And 5 more authors.
Molecular Ecology | Year: 2010

Knowledge of population structure and genetic diversity and the spatio-temporal demographic processes affecting populations is crucial for effective wildlife preservation, yet these factors are still poorly understood for organisms with large continuous ranges. Available population genetic data reveal that widespread mammals have for the most part only been carefully studied at the local population scale, which is insufficient for understanding population processes at larger scales. Here, we provide data on population structure, genetic diversity and gene flow in a brown bear population inhabiting the large territory of northwestern Eurasia. Analysis of 17 microsatellite loci indicated significant population substructure, consisting of four genetic groups. While three genetic clusters were confined to small geographical areas - located in Estonia, southern Finland and Leningrad oblast, Russia - the fourth cluster spanned a very large area broadly falling between northern Finland and the Arkhangelsk and Kirov oblasts of Russia. Thus, the data indicate a complex pattern where a fraction of the population exhibits large-scale gene flow that is unparalleled by other wild mammals studied to date, while the remainder of the population appears to have been structured by a combination of demographic history and landscape barriers. These results based on nuclear data are generally in good agreement with evidence previously derived using mitochondrial markers, and taken together, these markers provide complementary information about female-specific and population-level processes. Moreover, this study conveys information about spatial processes occurring over multiple generations that cannot be readily gained using other approaches, e.g. telemetry. © 2010 Blackwell Publishing Ltd.

Hindrikson M.,University of Tartu | Mannil P.,Estonian Environmental Research Center | Ozolins J.,State Forest Research Institute Silava | Krzywinski A.,Wildlife Park Kadzidlowo | Saarma U.,University of Tartu
PLoS ONE | Year: 2012

Studies on hybridization have proved critical for understanding key evolutionary processes such as speciation and adaptation. However, from the perspective of conservation, hybridization poses a concern, as it can threaten the integrity and fitness of many wild species, including canids. As a result of habitat fragmentation and extensive hunting pressure, gray wolf (Canis lupus) populations have declined dramatically in Europe and elsewhere during recent centuries. Small and fragmented populations have persisted, but often only in the presence of large numbers of dogs, which increase the potential for hybridization and introgression to deleteriously affect wolf populations. Here, we demonstrate hybridization between wolf and dog populations in Estonia and Latvia, and the role of both genders in the hybridization process, using combined analysis of maternal, paternal and biparental genetic markers. Eight animals exhibiting unusual external characteristics for wolves - six from Estonia and two from Latvia - proved to be wolf-dog hybrids. However, one of the hybridization events was extraordinary. Previous field observations and genetic studies have indicated that mating between wolves and dogs is sexually asymmetrical, occurring predominantly between female wolves and male dogs. While this was also the case among the Estonian hybrids, our data revealed the existence of dog mitochondrial genomes in the Latvian hybrids and, together with Y chromosome and autosomal microsatellite data, thus provided the first evidence from Europe of mating between male wolves and female dogs. We discuss patterns of sexual asymmetry in wolf-dog hybridization. © 2012 Hindrikson et al.

Hindrikson M.,University of Tartu | Remm J.,University of Tartu | Mannil P.,Estonian Environmental Research Center | Ozolins J.,State Forest Research Institute Silava | And 2 more authors.
PLoS ONE | Year: 2013

Spatial genetics is a relatively new field in wildlife and conservation biology that is becoming an essential tool for unravelling the complexities of animal population processes, and for designing effective strategies for conservation and management. Conceptual and methodological developments in this field are therefore critical. Here we present two novel methodological approaches that further the analytical possibilities of STRUCTURE and DResD. Using these approaches we analyse structure and migrations in a grey wolf (Canis lupus) population in north-eastern Europe. We genotyped 16 microsatellite loci in 166 individuals sampled from the wolf population in Estonia and Latvia that has been under strong and continuous hunting pressure for decades. Our analysis demonstrated that this relatively small wolf population is represented by four genetic groups. We also used a novel methodological approach that uses linear interpolation to statistically test the spatial separation of genetic groups. The new method, which is capable of using program STRUCTURE output, can be applied widely in population genetics to reveal both core areas and areas of low significance for genetic groups. We also used a recently developed spatially explicit individual-based method DResD, and applied it for the first time to microsatellite data, revealing a migration corridor and barriers, and several contact zones. © 2013 Hindrikson et al.

Idrizaj A.,Estonian University of Life Sciences | Laas A.,Estonian University of Life Sciences | Anijalg U.,Estonian Environmental Research Center | Noges P.,Estonian University of Life Sciences
Journal of Hydrology | Year: 2016

The causes of horizontal differences in metabolic activities between lake zones are still poorly understood. We carried out a two-year study of lake metabolism in two contrasting parts of a large shallow lake using the open-water technique based on high-frequency measurements of dissolved oxygen concentrations. We expected that the more sheltered and macrophyte-rich southern part of the lake receiving a high hydraulic load from the main inflow will exhibit equal or higher rate of metabolic processes compared to the open pelagic zone, and higher temporal variability, including anomalous metabolic estimates such as negative gross primary production (GPP) or community respiration (CR) due to rapid water exchange. Our results showed that anomalous metabolic estimates occurred at both stations with a similar frequency and were related rather to certain wind directions, which likely contributed to stronger water exchange between the littoral and pelagic zones. Periods of auto and heterotrophy (daily mean NEP> or <0) had a 50:50 distribution at the Central Station while the proportions were 30:70 at the Southern Station. High areal GPP estimated in our study exceeding nearly twice the long-term average 14C primary production, showed the advantages of the free-water technique in integrating the metabolism of all communities, a large part of which has remained undetected by the traditional bottle or chamber incubation techniques. © 2016 Elsevier B.V.

Roots O.,Estonian Environmental Research Center | Roots O.,University of Tartu | Roose A.,University of Tartu
Chemosphere | Year: 2013

The Water Framework Directive (WFD) aims to regulate the management of European surface water bodies. Directive 2008/105/EC, which establishes the environmental quality standards of priority substances and certain other pollutants, the content of which in the surface water should be monitored, has been transposed by the Estonian Ministry of Environment 9 September 2010 Regulation No. 49.Sampled hazardous substances were selected primarily based on their toxicity, as well as their lifetime in environment and ability to accumulate in living organisms (bioaccumulation). The contents of hazardous substances and their groups determined from Estonian surface waters remained below the limits of quantifications of used analysis methods in most cases. However, the content of some heavy metals, mono- and dibasic phenols in the surface water/waste water and sewage sludge/bottom sediments can still reach the delicate levels in the Estonian oil shale region in particular. Among new substances analysed in Estonia historically first time in 2010, amounts of organotin compounds in sediments and some alkylphenols, their ethoxylates and phthalates were found in various sample matrices. © 2013 Elsevier Ltd.

Ostonen I.,University of Tartu | Helmisaari H.-S.,University of Helsinki | Borken W.,University of Bayreuth | Tedersoo L.,University of Tartu | And 8 more authors.
Global Change Biology | Year: 2011

Fine root acclimation to different environmental conditions is crucial for growth and sustainability of forest trees. Relatively small changes in fine root standing biomass (FRB), morphology or mycorrhizal symbiosis may result in a large change in forest carbon, nutrient and water cycles. We elucidated the changes in fine root traits and associated ectomycorrhizal (EcM) fungi in 12 Norway spruce stands across a climatic and N deposition gradient from subarctic-boreal to temperate regions in Europe (68°N-48°N). We analysed the standing FRB and the ectomycorrhizal root tip biomass (EcMB, g m -2) simultaneously with measurements of the EcM root morphological traits (e.g. mean root length, root tissue density (RTD), N% in EcM roots) and frequency of dominating EcM fungi in different stands in relation to climate, soil and site characteristics. Latitude and N deposition explained the greatest proportion of variation in fine root traits. EcMB per stand basal area (BA) increased exponentially with latitude: by about 12.7 kg m -2 with an increase of 10° latitude from southern Germany to Estonia and southern Finland and by about 44.7 kg m -2 with next latitudinal 10° from southern to northern Finland. Boreal Norway spruce forests had 4.5 to 11 times more EcM root tips per stand BA, and the tips were 2.1 times longer, with 1.5 times higher RTD and about 1/3 lower N concentration. There was 19% higher proportion of root tips colonized by long-distance exploration type forming EcM fungi in the southern forests indicating importance of EcM symbiont foraging strategy in fine root nutrient acquisition. In the boreal zone, we predict ca. 50% decrease in EcMB per stand BA with an increase of 2 °C annual mean temperature. Different fine root foraging strategies in boreal and temperate forests highlight the importance of complex studies on respective regulatory mechanisms in changing climate. © 2011 Blackwell Publishing Ltd.

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