0000000000416374
AUTHOR
Agnija Skuja
showing 8 related works from this author
Maksteņu kāpuru (Trichoptera) sabiedrību ekoloģija Latvijas vidēja lieluma ritrāla tipa upēs
2011
Elektroniskā versija nesatur pielikumus
How to Assess the Ecological Status of Highly Humic Lakes? Development of a New Method Based on Benthic Invertebrates
2021
Highly humic lakes are typical for the boreal zone. These unique ecosystems are characterised as relatively undisturbed habitats with brown water, high acidity, low nutrient content and lack of macrophytes. Current lake assessment methods are not appropriate for ecological assessment of highly humic lakes because of their unique properties and differing human pressures acting on these ecosystems. This study proposes a new approach suitable for the ecological status assessment of highly humic lakes impacted by hydrological modifications. Altogether, 52 macroinvertebrate samples from 15 raised bog lakes were used to develop the method. The studied lakes are located in the raised bogs at the c…
Effects of changing climate on European stream invertebrate communities : A long-term data analysis
2018
Long-term observations on riverine benthic invertebrate communities enable assessments of the potential impacts of global change on stream ecosystems. Besides increasing average temperatures, many studies predict greater temperature extremes and intense precipitation events as a consequence of climate change. In this study we examined long-term observation data (10-32years) of 26 streams and rivers from four ecoregions in the European Long-Term Ecological Research (LTER) network, to investigate invertebrate community responses to changing climatic conditions. We used functional trait and multi-taxonomic analyses and combined examinations of general long-term changes in communities with deta…
Seasonal and diel patterns of mayfly (Ephemeroptera) drift in Korge stream, Latvia
2009
A complex set of biotic and abiotic factors affects a drift. Mayfly drift has been extensively studied worldwide, but the manner in which the environmental factors interact is not completely clear. The aim of the present study was to characterise mayfly seasonal and diel drift patterns in relation to abiotic factors in a medium-sized lowland stream in Latvia. Drift samples were collected at three-hour intervals in a riffle section in May, August and September 2007. Distinct seasonal and diel patterns of the mayfly drift were observed in the Korge stream. These were not directly infuenced by primary hydraulic factors e.g. current velocity and discharge, but depended on the active growth peri…
Biological quality metrics: their variability and appropriate scale for assessing Streams
2006
The concept of spatial scale is at the research frontier in ecology, and although focus has been placed on trying to determine the role of spatial scale in structuring communities, there still is a further need to standardize which organism groups are to be used at which scale and under which circumstances in environmental assessment. This paper contributes to the understanding of the variability at different spatial scales (reach, stream, river basin) of metrics characterizing communities of different biological quality elements (macrophytes, fishes, macroinvertebrates and benthic diatoms) as defined by the Water Framework Directive. For this purpose, high-quality reaches from medium-sized…
<strong>Microhabitat preference of caddisfly (Trichoptera) communities in a medium-sized lowland stream in Latvia</strong>
2011
The microhabitat preference of caddisfly (Trichoptera) communities was studied in 8 types of microhabitats in a fast-flowing, medium-sized, lowland stream in Latvia. A total 36 caddisfly taxa belonging to 14 families were recorded in microhabitat samples. A PCA biplot of caddisfly taxa abundance in microhabitats showed 3 distinct caddisfly taxa groups: depositional [Limnephilidae Gen. sp., Anabolia laevis (Zetterstedt) and Lasiocephala basalis (Kolenati)], lithal [ Agapetus ochripes Curtis and Psychomyia pusilla (Fabricius)], and submerged macrophyte and water moss caddisfly microhabitat communities ( Ithytrichia lamellaris Eaton, Hydropsyche siltalai Dohler and Hydropsyche spp. juv.). The …
Water quality in cutaway peatland lakes in Seda mire, Latvia
2011
Remediation of industrially-milled peatland is an important task in the sustainable management of natural resources. Several approaches for wetland restoration, depending on local climatic and hydrological conditions, topography, physico-chemical properties of peat, as well as peat mining techniques, have been developed worldwide. However, most of the restoration activities include regulation of hydrological regime and surface topography in order to reintroduce typical bog vegetation, especially, Sphagnum cover, and to restore the peatland’s ecosystem close to its original conditions (Gorham and Rochefort, 2003; Farrell and Doyle, 2003; Lamers et al., 2002). In many countries, a significant…
Science Advances
2019
River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constrai…