A5090497298- Freshwater macroinvertebrate diversity and ecology
- Fish Ecology and Management Studies
- Aquatic Invertebrate Ecology and Behavior
- Invertebrate Taxonomy and Ecology
- Species Distribution and Climate Change
- Bipolar Disorder and Treatment
- Hydrology and Watershed Management Studies
- Ecology and biodiversity studies
- Physiological and biochemical adaptations
- Geology and Paleoclimatology Research
- Soil and Water Nutrient Dynamics
- Aquatic Ecosystems and Phytoplankton Dynamics
- Environmental DNA in Biodiversity Studies
- Acute Kidney Injury Research
- Hydrology and Sediment Transport Processes
- Lepidoptera: Biology and Taxonomy
- Diatoms and Algae Research
- Wildlife Ecology and Conservation
- Peatlands and Wetlands Ecology
- Cryospheric studies and observations
- Isotope Analysis in Ecology
- Land Use and Ecosystem Services
- Marine and coastal ecosystems
- Forest Ecology and Biodiversity Studies
- Marine and fisheries research
University of Iceland
2014-2024
National University Hospital of Iceland
2023-2024
Akureyri Hospital
2024
John Wiley & Sons (United States)
2020
Ecological Society of America
2020
Westmead Hospital
1997
The University of Sydney
1997
Icelandic Fisheries Laboratories
1994-1996
UiT The Arctic University of Norway
1996
Glaciers cover ∼10% of the Earth's land surface, but they are shrinking rapidly across most parts world, leading to cascading impacts on downstream systems. impart unique footprints river flow at times when other water sources low. Changes in hydrology and morphology caused by climate-induced glacier loss projected be greatest any hydrological system, with major implications for riverine near-shore marine environments. Here, we synthesize current evidence how shrinkage will alter regimes,...
1. It is becoming increasingly clear that fresh waters play a major role in the global C cycle. Stream ecosystem respiration (ER) and gross primary productivity (GPP) exert significant control on organic carbon fluxes fluvial networks. However, little known about how climate change will influence these fluxes. 2. Here, we used ‘natural experiment’ to demonstrate of temperature nutrient cycling whole-system metabolism (ER, GPP net production – NEP), naturally heated geothermal (5–25 °C)...
Summary 1. We studied 10 first‐order Icelandic streams differing in geothermal influence separate catchments. Summer temperature (August–September) ranged between 6 and 23 °C. 2. Macroinvertebrate evenness species overlap decreased significantly with whereas taxon richness showed no response. In total, 35 macroinvertebrate were found Chironomidae the dominant taxonomic group. density increased temperature. Dominant warm Lymnaea peregra Simulium vittatum . Algal biomass, macrophyte cover...
Global warming is widely predicted to reduce the biomass production of top predators, or even result in species loss. Several exceptions this expectation have been identified, however, and it vital that we understand underlying mechanisms if are improve our ability predict future trends. Here, used a natural experiment Iceland quantitative theoretical predictions investigate success brown trout as predators across stream temperature gradient (4-25 °C). Brown at northern limit their...
1. The influence of 11 environmental variables on benthic macroinvertebrate communities was examined in seven glacier‐fed European streams ranging from Svalbard the north to Pyrenees south. Between 4 and near‐pristine reaches were studied each stream 1996–97. 2. Taxonomic richness, measured at family or subfamily (for Chironomidae) levels for insects higher non‐insects, increased with latitude (3 taxa) (29 taxa). 3. A Generalized Additive Model (GAM) incorporating channel stability [Pfankuch...
Abstract The Earth is experiencing historically unprecedented rates of warming, with surface temperatures projected to increase by 3–5 °C globally, and up 7.5 in high latitudes, within the next century. Knowledge how this will affect biological systems still largely restricted lower levels organization (e.g. species range shifts), rather than at community, food web or ecosystem level, where responses cannot be predicted from studying single isolation. Further, many correlational studies are...
Abstract Although much effort has been devoted to quantifying how warming alters carbon cycling across diverse ecosystems, less is known about these changes are linked the of bioavailable nitrogen and phosphorus. In freshwater benthic biofilms (i.e. thin films algae, bacteria, fungi, detrital matter) act as biogeochemical hotspots by controlling important fluxes energy material. Understanding respond thus critical for predicting responses coupled elemental cycles in systems. We developed...
Abstract Climate warming is affecting the structure and function of river ecosystems, including their role in transforming transporting carbon (C), nitrogen (N), phosphorus (P). Predicting how ecosystems respond to has been hindered by a dearth information about otherwise well‐studied physiological responses temperature scale from organismal ecosystem levels. We conducted an ecosystem‐level manipulation quantify coupling stream metabolism nutrient uptake responded realistic scenario. A...
How ecological communities respond to predicted increases in temperature will determine the extent which Earth's biodiversity and ecosystem functioning can be maintained into a warmer future. Warming is alter structure of natural communities, but robust tests such predictions require appropriate large-scale manipulations intact, habitat that open dispersal processes via exchange with regional species pools. Here, we report results two-year whole-stream warming experiment shifted invertebrate...
A central question at the interface of food-web and climate change research is how secondary production, or formation heterotroph biomass over time, will respond to rising temperatures. The metabolic theory ecology (MTE) hypothesizes temperature-invariance driven by matched opposed forces that reduce heterotrophs while increasing their turnover rate (production : biomass, P:B) with warming. To test this prediction whole community level, we used a geothermal heat exchanger experimentally warm...
Abstract Warming can have profound impacts on ecological communities. However, explorations of how differences in biogeography and productivity might reshape the effect warming been limited to theoretical or proxy-based approaches: for instance, studies latitudinal temperature gradients are often conflated with other drivers (e.g., species richness). Here, we overcome these limitations by using local geothermal across multiple high-latitude stream ecosystems. Each suite streams (6-11 warmed...
The ongoing retreat of glaciers driven by climate change is predicted to significantly alter the ecological dynamics glacier-fed streams, including changes in macroinvertebrate community composition. Previous studies suggest that increased water temperatures and altered channel stability due glacial initially decrease α-diversity elevated runoff, followed an eventual rise diversity upstream shifts species. Additionally, β-diversity expected along stream as highly adapted...
Summary Tanytarsus gracilentus population dynamics in Lake Myvatn show a tendency to cycle, with three oscillations occurring between 1977 and 1999 having periods of roughly 7 years. The abundance fluctuated over four orders magnitude. A partial autocorrelation function (PACF) accounting for measurement error revealed strong positive lag‐1 moderate negative lag‐2 autocorrelation. This suggests that the can be explained by simple second‐order autoregressive process. We tested alternative...
SUMMARY. 1. A window trap is described which has been found useful in the study of fight periodicity chironomids and simuliids. simple to construct can be operated high winds. 2. Window traps were 1977 1478 at Lake Myvatn. Iceland, when thirty‐nine chironomid species two simuliid caught. Most had peaks flight activity per year. e.g. Eukiefferietla minor, Cricotftpus tibialis. Pogonocladius consohrinus, Tanytaraus gracilentus Micropsectra airofasciata. Chironomus islandicus...
1. Spring-fed streams, with temperatures ranging from 7.1 to 21.6 °C, in an alpine geothermal area SW Iceland were chosen test hypotheses on the effects of nutrients and temperature stream primary producers. Ammonium nitrate was dripped into lower reaches eight higher being used as controls, during summers 2006 2007. Dry mass larger producers, epilithic chlorophyll a biovolumes algae measured. 2. Bryophyte communities dominated by Fontinalis antipyretica, biomass greatest warmest streams....
Abstract Climate warming and eutrophication are leading drivers of environmental change, both likely to alter the role freshwaters in global carbon cycle. Recent studies demonstrate that streams can increase freshwater contributions CO 2 atmosphere, yet little is known about how such modulated by identity or supply limiting nutrients. We quantified responses ecosystem metabolism metabolic balance whole‐stream enrichments either nitrogen phosphorus across a 5°C range ambient temperature. show...
Abstract Although scientific research has identified the causes of undesirable ecological changes in fresh waters, translating results into practical conservation and management, raising awareness need for action, is often inadequate. This Viewpoint considers present coverage conservation‐related freshwater research, application science to conservation, extent collaboration between international organizations, level ecosystems their conservation. Far greater attention been given marine than...