Publikācijas | Didzis Elferts

Serotoninergic Modulation of Phototactic Variability Underpins a Bet-Hedging Strategy in Drosophila melanogaster

When organisms’ environmental conditions vary unpredictably in time, it can be advantageous for individuals to hedge their phenotypic …

Indrikis A. Krams, Tatjana Krama, Ronalds Krams, Giedrius Trakimas, Sergejs Popovs, Priit Jõers, Maris Munkevics, Didzis Elferts, Markus J Rantala, Jānis Makņa, Benjamin L. de Bivort

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Socioeconomic position, immune function, and its physiological markers

The development of costly traits such as immune function and secondary sexual traits is constrained by resource availability. The …

Severi Luoto, Tatjana Krama, Anna Rubika, Javier I. Borráz-León, Giedrius Trakimas, Didzis Elferts, Ilona Skrinda, Ronalds Krams, Fhionna R. Moore, Elza Birbele, Irena Kaminska, Jorge Contreras-Garduño, Markus J. Rantala, Indrikis A. Krams

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Storm legacies shaping post-windthrow forest regeneration: learnings from spatial indices in unmanaged {Norway} spruce stands

The anticipated increase in extreme disturbance events due to climate change is likely to expose Norway spruce (Picea abies (L.) …

Endijs Bāders, Kalev Jõgiste, Didzis Elferts, Floorthe Vodde, Andres Kiviste, Solveiga Luguza, Āris Jansons

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Long-Term Influence of Stump-Removal on Components of Hemiboreal Pine Forest Ecosystem

Use of whole tree biomass becomes increasingly more important due to rising demand for renewable energy and materials to replace fossil …

Roberts Čakšs, Linda Čakša, Iveta Desaine, Zane Lībiete, Didzis Elferts, Aldis Butlers, Āris Jansons

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Norway spruce seedlings from an eastern Baltic provenance show tolerance to simulated drought

In Northern Europe, an increase in heterogeneity of summer precipitation regime will subject forests to water deficit and drought. This …

Roberts Matisons, Oskars Krišāns, Āris Jansons, Toms Kondratovičs, Didzis Elferts, Gederts Ievinsh

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Wind Resistance of Eastern Baltic Silver Birch (Betula pendula Roth.) Suggests Its Suitability for Periodically Waterlogged Sites

Storms and wind damage are the main cause of biomass loss in forests of Northern Europe, as well as they are synergic with the …

Oskars Krisans, Roberts Matisons, Māra Kitenberga, Jānis Donis, Steffen Rust, Didzis Elferts, Āris Jansons

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Non-linear regional weather-growth relationships indicate limited adaptability of the eastern Baltic Scots pine

Under changing climate, temporal and spatial stability (stationarity) of growth responses of trees to weather and climate, which has …

Roberts Matisons, Didzis Elferts, Oskars Krišāns, Volker Schneck, Holger Gärtner, Alexander Bast, Tomasz Wojda, Jan Kowalczyk, Āris Jansons

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Effect of Stem Snapping on Aspen Timber Assortment Recovery in Hemiboreal Forests

Post-disturbance salvage logging mitigates economic loss after windthrow, and the value of salvaged timber is strongly linked to its …

Linda Čakša, Silva Šēnhofa, Guntars Šnepsts, Didzis Elferts, Līga Liepa, Āris Jansons

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Species composition modulates seedling competitiveness of temperate tree species under hemiboreal conditions

Mixed stands are advised for reduction of impacts of natural hazards, and species composition can largely affect sustainability and …

Roberts Matisons, Annija Kārkliņa, Oskars Krišāns, Didzis Elferts, Āris Jansons

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Egalitarian mixed-species bird groups enhance winter survival of subordinate group members but only in high-quality forests

Indrikis A. Krams, Severi Luoto, Tatjana Krama, Ronalds Krams, Kathryn Sieving, Giedrius Trakimas, Didzis Elferts, Markus J Rantala, Eben Goodale

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Estimates of Tree Canopy Closure and Basal Area as Proxies for Tree Crown Volume at a Stand Scale

Research Highlights: Studies on tree canopy dwelling species often require simple proxies of tree canopy volume estimated at a stand …

Guntis Brūmelis, Iluta Dauškane, Didzis Elferts, Linda Strode, Tatjana Krama, Indrikis Krams

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Effect of salvage-logging on post-fire tree establishment and ground cover vegetation in semi-natural hemiboreal forests

Fire is a common disturbance in boreal forests causing changes in biological diversity at various spatial scales. In the past 100 …

Annija Kārkliņa, Guntis Brūmelis, Iluta Dauškane, Didzis Elferts, Lāsma Freimane, Māra Kitenberga, Zane Lībiete, Roberts Matisons, Āris Jansons

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Relationship Between Functional Traits, Functional Types, and Habitat in Boreonemoral Bryophytes

The aim of the present study was to determine a relationship between physiological traits and functional types of bryophytes from five …

Gederts Ievinsh, Laura Gaile, Didzis Elferts, Ligita Liepiņa

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Salt accumulation and effects within foliage of Tilia × vulgaris trees from the street greenery of Riga, Latvia

Green infrastructures within sprawling cities provide essential ecosystem services, increasingly undermined by environmental stress. …

Gunta Cekstere, Anita Osvalde, Didzis Elferts, Christophe Rose, Falk Lucas, Pierre Vollenweider

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Women's socioeconomic position in ontogeny is associated with improved immune function and lower stress, but not with height

Immune function, height and resource accumulation comprise important life history traits in humans. Resource availability models …

Anna Rubika, Severi Luoto, Tatjana Krama, Giedrius Trakimas, Markus J. Rantala, Fhionna R. Moore, Ilona Skrinda, Didzis Elferts, Ronalds Krams, Jorge Contreras-Garduño, Indrikis A. Krams

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Norway Spruce Survival Rate in Two Forested Landscapes, 1975–2016

The increasing frequency and severity of natural disturbances (e.g., storms and insect outbreaks) due to climate change are expected to …

Endijs Bāders, Oskars Krišāns, Jānis Donis, Didzis Elferts, Ieva Jaunslaviete, Āris Jansons

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Stem Damage Modifies the Impact of Wind on Norway Spruces

Bark stripping caused by cervids can have a long-lasting negative effect on tree vitality. Such trees of low vitality might be more …

Guntars Snepsts, Mara Kitenberga, Didzis Elferts, Janis Donis, Aris Jansons

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Effect of Bark-Stripping on Mechanical Stability of Norway Spruce

The increasing effects of storms are considered the main abiotic disturbance affecting forest ecosystems. Bark-stripping damage from …

Oskars Krisans, Renate Saleniece, Steffen Rust, Didzis Elferts, Rolands Kapostins, Aris Jansons, Roberts Matisons

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Occurrence of ‘blue' and ‘frost' rings reveal frost sensitivity of eastern Baltic provenances of Scots pine

Assisted gene flow is advised as one of the most effective means to sustain the productivity of forests under warming climate via …

Roberts Matisons, Holger Gärtner, Didzis Elferts, Annija Kārkliņa, Andis Adamovičs, Āris Jansons

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Advance Regeneration of Norway Spruce and Scots Pine in Hemiboreal Forests in Latvia

Continuous cover forestry (CCF) aims to emulate small natural disturbances and take advantage of natural regeneration. To implement …

Solveiga Luguza, Guntars Snepsts, Janis Donis, Iveta Desaine, Endijs Baders, Mara Kitenberga, Didzis Elferts, Aris Jansons

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Presence of Root Rot Reduces Stability of Norway Spruce (Picea abies): Results of Static Pulling Tests in Latvia

Storms are the main abiotic disturbance in European forests, effects of which are expected to intensify in the future, hence the …

Oskars Krisans, Roberts Matisons, Steffen Rust, Natalija Burnevica, Lauma Bruna, Didzis Elferts, Liene Kalvane, Aris Jansons

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Effect of salvage logging and forest type on the post-fire regeneration of Scots pine in hemiboreal forests

In post-disturbance areas, salvage logging is a common management practice that can negatively affect ecosystem services and alter …

Mara Kitenberga, Didzis Elferts, Andis Adamovics, Juris Katrevics, Janis Donis, Endijs Baders, Aris Jansons

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Ecological Stoichiometry: A Link Between Developmental Speed and Physiological Stress in an Omnivorous Insect

Giedrius Trakimas, Ronalds Krams, Tatjana Krama, Raine Kortet, Shahi Haque, Severi Luoto, Sarah Eichler Inwood, David M. Butler, Priit Jõers, Dror Hawlena, Markus J. Rantala, Didzis Elferts, Jorge Contreras-Garduño, Indrikis Krams

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Plasticity of response of tree-ring width of Scots pine provenances to weather extremes in Latvia

Climatic changes and weather extremes are causing shifts in distribution of tree species, affecting productivity of forests. With the …

Roberts Matisons, Diāna Jansone, Didzis Elferts, Andis Adamovičs, Volker Schneck, Āris Jansons

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Geographic determinants of spatial patterns of Quercus robur forest stands in Latvia: biophysical conditions and past management

Most of the forest area dominated by pedunculate oak (Quercus robur L.) in Latvia was lost to arable land several centuries ago and the …

Zigmars Rendenieks, Guntis Brumelis, Olgerts Nikodemus, Didzis Elferts

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Effects of stand-level and landscape factors on understorey plant community traits in broad-leaved forest of the boreo-nemoral zone in Latvia

Knowledge of the limiting processes shaping the composition of plant communities of woodland is important in conservation of biological …

Guntis Brūmelis, Anna Artistova, Didzis Elferts, Raimonds Kasparinskis, Oļģerts Nikodemus, Vita Amatniece, Zigmārs Rendenieks

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A mixture of human and climatic effects shapes the 250-year long fire history of a semi-natural pine dominated landscape of Northern Latvia

Fire has been shown to shape successional pathways and dynamics of forest vegetation. However, its role in European hemiboreal forests …

Mara Kitenberga, Igor Drobyshev, Didzis Elferts, Roberts Matisons, Andis Adamovics, Juris Katrevics, Mats Niklasson, Aris Jansons

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A head start for life history development? Family income mediates associations between height and immune response in men

Objectives: Male height and health affect a diverse range of social and economic outcomes such as competition for resources and mates. …

Indrikis Krams, Severi Luoto, Anna Rubika, Tatjana Krama, Didzis Elferts, Ronalds Krams, Sanita Kecko, Ilona Skrinda, Fhionna R. Moore, Markus J. Rantala

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Landscape Diversity for Reduced Risk of Insect Damage: A Case Study of Spruce Bud Scale in Latvia

Spruce bud scale (Physokermes piceae (Schrnk.)) has gained attention due to recent outbreaks in the eastern Baltic Sea region—Poland, …

Endijs Bāders, Āris Jansons, Roberts Matisons, Didzis Elferts, Iveta Desaine

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Prevalence and Antimicrobial Resistance of Escherichia coli, Enterococcus spp. and the Major Foodborne Pathogens in Calves in Latvia

The aim of the present study was to detect the prevalence and antimicrobial resistance of fecal indicators and major foodborne …

Margarita Terentjeva, Madara Streikiša, Jeļena Avsejenko, Jūlija Trofimova, Kaspars Kovaļenko, Didzis Elferts, Aivars Bērziņš

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Population Genetics of Latvians in the Context of Admixture between North-Eastern European Ethnic Groups

textlessptextgreater This article presents a review on population genetics of Latvians, which alongside Lithuanians are the two extant …

Astrida Krumiņa, Liana Pliss, Gunita Zariņa, Agrita Puzuka, Agnese Zariņa, Baiba Lace, Didzis Elferts, Andrey Khrunin, Svetlana Limborska, Janis Kloviņš, Linda Gailite Piekuse

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Macrophyte assessment in European lakes: Diverse approaches but convergent views of ‘good' ecological status

The European Water Framework Directive has been adopted by Member States to assess and manage the ecological integrity of surface …

Sandra Poikane, Rob Portielje, Luc Denys, Didzis Elferts, Martyn Kelly, Agnieszka Kolada, Helle Mäemets, Geoff Phillips, Martin Søndergaard, Nigel Willby, Marcel S. van den Berg

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Linking organismal growth, coping styles, stress reactivity, and metabolism via responses against a selective serotonin reuptake inhibitor in an insect

Evidence suggests that brain serotonin (5-HT) is one of the central mediators of different types of animal personality. We tested this …

Indrikis Krams, Giedrius Trakimas, Sanita Kecko, Didzis Elferts, Ronalds Krams, Severi Luoto, Markus J. Rantala, Marika Mänd, Aare Kuusik, Jukka Kekäläinen, Priit Jõers, Raine Kortet, Tatjana Krama

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Carbon pools in a hemiboreal over-mature Norway spruce stands

Old unmanaged forests are commonly assumed to be carbon neutral; however, there is still a lack of reference studies available to …

Laura Ķeniņa, Didzis Elferts, Endijs Baders, Aris Jansons

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Bilberry ramet dimensions in relation to stand age in oligotrophic conditions in Latvia

Dwarf shrub layer is an important component of boreal and hemiboreal forest ecosystems that has received little attention, particularly …

Linda Robalte, Diāna Jansone, Didzis Elferts, Roberts Matisons, Āris Jansons

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Assessment of site-specific drivers of farmland abandonment in mosaic-type landscapes: A case study in Vidzeme, Latvia

Farmland abandonment, which causes changes in rural life and farming practices, can be observed throughout Europe. Over the last …

Ivo Vinogradovs, Oļģerts Nikodemus, Didzis Elferts, Guntis Brūmelis

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Sex‐specific compensatory growth in the larvae of the greater wax moth Galleria mellonella

Deficiency of food resources in ontogeny is known to prolong an organism’s developmental time and affect body size in adulthood. …

S. Kecko, A. Mihailova, K. Kangassalo, Didzis Elferts, T. Krama, R. Krams, S. Luoto, M. J. Rantala, I. A. Krams

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Tree regeneration in noble broadleaved tree stands at their northern limit: implications for conservation management

Guntis Brūmelis, Sandra Ikauniece, Anna Voiceščuka, Anna Artistova, Agita Treimane, Iluta Dauškane, Didzis Elferts, Didzis Tjarve

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Reproduction compromises adaptive immunity in a cyprinid fish

Indrikis A. Krams, Katariina Rumvolt, Lauri Saks, Ronalds Krams, Didzis Elferts, Jolanta Vrublevska, Markus J. Rantala, Sanita Kecko, Dina Cīrule, Severi Luoto, Tatjana Krama

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Microbiome symbionts and diet diversity incur costs on the immune system of insect larvae

Indrikis A. Krams, Sanita Kecko, Priit Jõers, Giedrius Trakimas, Didzis Elferts, Ronalds Krams, Severi Luoto, Markus J. Rantala, Inna Inashkina, Dita Gudrā, Dāvids Fridmanis, Jorge Contreras-Garduño, Lelde Grantiņa-Ieviņa, Tatjana Krama

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Impact of climate variability, drainage and land-cover changes on hemiboreal streamflow

AbstractThe aim of the study was to determine the effects of climate variability, agricultural land drainage and afforestation of …

Elga Apsīte, Oļģerts Nikodemus, Guntis Brūmelis, Ainis Lagzdiņš, Didzis Elferts, Zigmārs Rendenieks, Līga Klints

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Habitat quality affects stress responses and survival in a bird wintering under extremely low ambient temperatures

Animals normally respond to stressful environmental stimuli by releasing glucocorticoid hormones. We investigated whether baseline …

Dina Cīrule, Tatjana Krama, Ronalds Krams, Didzis Elferts, Ants Kaasik, Markus J. Rantala, Pranas Mierauskas, Severi Luoto, Indrikis A. Krams

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Food quality affects the expression of antimicrobial peptide genes upon simulated parasite attack in the larvae of greater wax moth

Indrikis Krams, Sanita Kecko, Inna Inashkina, Giedrius Trakimas, Ronalds Krams, Didzis Elferts, Jolanta Vrublevska, Priit Jõers, Markus J. Rantala, Severi Luoto, Jorge Contreras-Garduño, Līga Jankevica, Laila Meija, Tatjana Krama

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Bryophyte and polypore richness and indicators in relation to type, age and decay stage of coarse woody debris of Picea abies

Guntis Brūmelis, Evita Oļehnoviča, Undīne Šūba, Agita Treimane, Sintija Inne, Egita Zviedre, Didzis Elferts, Mārtiņš Dakša, Didzis Tjarve

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Vegetation changes in boreo–nemoral forest stands depending on soil factors and past land use during an 80 year period of no human impact

Information on the long-term changes in plant communities that occur without human interference is limited, due to insufficient studies …

Ilze Kokarēviča, Guntis Brūmelis, Raimonds Kasparinskis, Arta Rolava, Oļģerts Nikodemus, John Grods, Didzis Elferts

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Long-term changes of the ice regime of rivers in Latvia

Inese Latkovska, Elga Apsīte, Didzis Elferts

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Long-term changes of daugava river ice phenology under the impact of the cascade of hydro power plants

This paper presents the results of the study of long-term changes of Daugava River ice phenology, i.e. the freeze-up date, the break-up …

Elga Apsite, Didzis Elferts, Inese Latkovska

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Genotype and allele frequencies of isoniazid-metabolizing enzymes NAT2 and GSTM1 in Latvian tuberculosis patients

Pharmacogenomic testing of tuberculosis drug-metabolizing enzyme genes was proposed as a strategy to identify patients at risk for …

Viktorija Igumnova, Valentina Capligina, Alvils Krams, Andra Cirule, Didzis Elferts, Ilva Pole, Inta Jansone, Dace Bandere, Renate Ranka

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Diet overlap between juvenile flatfish and the invasive round goby in the central Baltic Sea

The present study offers a comprehensive analysis of changes in the abundance and diet composition of juvenile flounder (Platichthys …

Didzis Ustups, U. Bergström, A.B. Florin, E. Kruze, D. Zilniece, Didzis Elferts, E. Knospina, D. Uzars

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Baltic herring prey selectively on older copepodites of Eurytemora affinis and Limnocalanus macrurus in the Gulf of Riga

Zooplankton availability is a major factor affecting herring body condition that in turn describes its well-being. As herring feeding …

Lina Livdane, Ivars Putnis, Gunta Rubene, Didzis Elferts, Anda Ikauniece

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Assessment of Factors of Landscape Change in Mosaic Type Landscape: a Case Study of Vidzeme, Latvia

Ivo Vinogradovs, Oļģerts Nikodemus, Guntis Tabors, Imants Krūze, Didzis Elferts

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Tidal, diel and lunar patterns in intertidal and subtidal mangrove creek fish assemblages from southwest Thailand

Knowledge about short-term assembly patterns and connectivity in estuarine mangrove ichthyofauna from the Indo-West Pacific region is …

Uwe Krumme, Kalvis Grinvalds, Matiss Zagars, Didzis Elferts, Kou Ikejima, Prasert Tongnunui

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Reproduction of Baltic cod, Gadus morhua (Actinopterygii: Gadiformes: Gadidae), in the Gotland Basin: Causes of annual variability

Background. The Gotland Basin spawning ground is one of three main$backslash$nspawning areas of Baltic cod, Gadus morhua Linnaeus, …

Maris Plikshs, Hans Harald Hinrichsen, Didzis Elferts, Ivo Sics, Georgs Kornilovs, Friedrich W. Köster

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Comparison of telomere length between population-specific mitochondrial haplogroups among different age groups in a Latvian population

Population studies have demonstrated that telomere length (TL) displays great diversity among different populations. Previously …

Egija Zole, Didzis Elferts, Janis Kimsis, Astrida Krumina, Kristaps Narels, Ilva Pole, Renate Ranka, Liana Pliss

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Arbuscular mycorrhizal colonization in roots of sand dune plants in relation to soil factors

Seacoast plant communities represent primary successions characterized by a harsh environment in which mycorrhizal symbioses are known …

Ligita Liepiņa, Arta Dimbiere, Brigita Laime, Didzis Tjarve, Didzis Elferts, Guntis Tabors, Guntis Brūmelis

Long-term changes in hydrological regime of the lakes in Lavia

Changes in the hydrological regime of the lakes of Latvia depend on natural and anthropogenic causes. This publication summarises the …

Elga Apsite, Didzis Elferts, Andrejs Zubanics, Inese Latkovska

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Influence of the initial acidification step on biogas production and composition

Laboratory-scale experiments were carried out to evaluate the effect of initial acidification of feedstock consisting of different …

Ilze Dirnena, Ilze Dimanta, Arturs Gruduls, Janis Kleperis, Didzis Elferts, Vizma Nikolajeva

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Possible signs of growth decline of pedunculate oak in Latvia during 1980-2009 in tree-ring width and vessel size

The present study reports on action research conducted using a resource wiki. Participants included 48 certified teachers and …

Roberts Matisons, Didzis Elferts, Guntis Brumelis

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Pointer years in tree-ring width and earlywood-vessel area time series of Quercus robur—Relation with climate factors near its northern distribution limit

Roberts Matisons, Didzis Elferts, Guntis Brūmelis

Changes in Latvian river discharge regime at the turn of the century

The study deals with turn-of-the-century changes in the total annual river runoff distribution and high and low flows in Latvia, …

Elga Apsite, Ilze Rudlapa, Inese Latkovska, Didzis Elferts

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Response of Scots pine radial growth to past and future climate change in Latvia

Didzis Elferts, Āris Jansons

Natural structures and disturbances in an old growth wet Norway spruce forest in the nature reserve

Linda Robalte, Roberts Matisons, Didzis Elferts, Guntis Brūmelis

Forecasted changes in the climate and the river runoff regime in Latvian river basins

Inkjet printing is considered to be a key technology in the field of defined polymer deposition. This article provides an introduction …

Inese Latkovska, Elga Apsite, Didzis Elferts, Liga Kurpniece

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Changes in climatic signals of English oak tree-ring width and cross-section area of earlywood vessels in Latvia during the period 1900-2009

We investigated changes in response of wood formation in English oak (Quercus robur L.) to climatic factors since 1900. It was …

Roberts Matisons, Didzis Elferts, Guntis Brumelis

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Changes in climate and discharge regime in Latvia at the End of the 21st century

Inese Latkovska, Elga Apsīte, Līga Kurpniece, Didzis Elferts

The link between mitochondrial DNA hypervariable segment I heteroplasmy and ageing among genetically unrelated Latvians

Various studies have demonstrated that mitochondrial DNA (mtDNA) heteroplasmy tends to increase with age and that the observed …

Liana Pliss, Andis Brakmanis, Renate Ranka, Didzis Elferts, Astrida Krumina, Viesturs Baumanis

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Preliminary Characteristics of Ecological and Socioeconomic Components and their Interaction within the Long Term Socioecological Research Platform of Latvia

Review of previous ecological and socioeconomic studies performed in the drainage basin of Lake Engure - the long-term socioecological …

Viesturs Melecis, Zaiga Krisjane, Maris Klavins, Juris Aigars, Didzis Elferts, Janis Viksne

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