Søk
Viser treff 21-30 av 36
Contrasting Population and Life History Responses of a Young Morph-Pair of European Whitefish to the Invasion of a Specialised Coregonid Competitor, Vendace
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
Invasions of non-native species represent a global problem of great scientific interest. Here we study in detail the response in population and life history characteristics of closely related native species, with divergent habitat preferences, that are impacted by an invading species over a sufficient time period to allow a new stable state to become established. A time series of 20 years starting ...
A way forward with eco evo devo: an extended theory of resource polymorphism with postglacial fishes as model systems
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-19)
A major goal of evolutionary science is to understand how biological diversity is generated and altered. Despite considerable advances, we still have limited insight into how phenotypic variation arises and is sorted by natural selection. Here we argue that an integrated view, which merges ecology, evolution and developmental biology (eco evo devo) on an equal footing, is needed to understand the ...
From clear lakes to murky waters – tracing the functional response of high-latitude lake communities to concurrent ‘greening’ and ‘browning’
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-21)
Climate change and the intensification of land use practices are causing widespread eutrophication of subarctic lakes. The implications of this rapid change for lake ecosystem function remain poorly understood. To assess how freshwater communities respond to such profound changes in their habitat and resource availability, we conducted a space‐for‐time analysis of food‐web structure in 30 lakes ...
The effect of inter- and intraspecific competition on individual and population niche widths: a four-decade study on two interacting salmonids
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-12)
Competition is assumed to shape niche widths, affecting species survival and coexistence. Expectedly, high interspecific competition will reduce population niche widths, whereas high intraspecific competition will do the opposite. Here we test in situ how intra- and interspecific competition affects trophic resource use and the individual and population niche widths of two lacustrine fish species, ...
The role of gill raker number variability in adaptive radiation of coregonid fish
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010-07-27)
Gill raker divergence is a general pattern in adaptive radiations of postglacial fish, but few studies have addressed the adaptive significance of this morphological trait in foraging and eco-evolutionary interactions among predator and prey. Here, a set of subarctic lakes along a diversifying gradient of coregonids was used as the natural setting to explore correlations between gill raker numbers ...
High parasite diversity in the amphipod Gammarus lacustris in a subarctic lake
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-05)
Amphipods are often key species in aquatic food webs due to their functional roles in the ecosystem and as intermediate hosts for trophically transmitted parasites. Amphipods can also host many parasite species, yet few studies address the entire parasite community of a gammarid population, precluding a more dynamic understanding of the food web. We set out to identify and quantify the parasite ...
Cercarial behaviour alters the consumer functional response of three-spined sticklebacks
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-22)
<ol>
<li>Free-living parasite life stages may contribute substantially to ecosystem biomass and thus represent a significant source of energy flow when consumed by non-host organisms. However, ambient temperature and the predator's own infection status may modulate consumption rates towards parasite prey.</li>
<li>We investigated the combined effects of temperature and predator infection status ...
Taxa-specific activity loss and mortality patterns in freshwater trematode cercariae under subarctic conditions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-11)
Cercarial activity and survival are crucial traits for the transmission of trematodes. Temperature is particularly important, as faster depletion of limited cercarial energy reserves occurs at high temperatures. Seasonal climate conditions in high latitude regions may be challenging to complete trematode life cycle during the 6-month ice-free period, but temperature effects on the activity and ...
Temperature does not influence functional response of amphipods consuming different trematode prey
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-26)
Direct consumption on free-living cercariae stages of trematodes by non-host organisms interferes with trematode transmission and leads to reduced infections in the next suitable hosts. Consumer functional responses provide a useful tool to examine relationships between consumption rates and ecologically relevant prey densities, whilst also accounting for abiotic factors that likely influence ...
Long-term ecological studies in northern lakes – challenges, experiences, and accomplishments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-15)
We review three long‐term research programs performed over the last four decades on the ecology and management of oligotrophic lake systems with different fish communities at 69° N in Norway. Through whole‐lake perturbation experiments, intensive culling of stunted fish removed 35 tons (1984–1991) of Arctic charr <i>Salvelinus alpinus</i> in Takvatn (15 km<sup>2</sup>) and 153 tons (1981–1983, ...