SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "hsv:(NATURVETENSKAP) hsv:(Biologiska vetenskaper) hsv:(Ekologi) "

Sökning: hsv:(NATURVETENSKAP) hsv:(Biologiska vetenskaper) hsv:(Ekologi)

  • Resultat 51-60 av 81
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
51.
  • Holopainen, Sari, et al. (författare)
  • Sustainable management of migratory European ducks : finding model species
  • 2018
  • Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research (NKV). - 0909-6396 .- 1903-220X.
  • Tidskriftsartikel (refereegranskat)abstract
    • Eurasian migratory duck species represent a natural resource shared between European countries. As is evident throughout human harvest history, lack of coordinated management and monitoring at appropriate levels often leads to ‘the tragedy of the commons’, where shared populations suffer overexploitation. Effective management can also be hampered by poor understanding of the factors that limit and regulate migratory populations throughout their flyways, and over time. Following decades of population increase, some European duck populations now show signs of levelling off or even decline, underlining the need for more active and effective management. In Europe, the existing mechanisms for delivering effective management of duck populations are limited, despite the need and enthusiasm for establishing adaptive management (AM) schemes for wildlife populations. Existing international legal agreements already oblige European countries to sustainably manage migratory waterbirds. Although the lack of coordinated demographic and hunting data remains a challenge to sustainable management planning, AM provides a robust decision-making framework even in the presence of uncertainty regarding demographic and other information. In this paper we investigate the research and monitoring needs in Europe to successfully apply AM to ducks, and search for possible model species, focusing on freshwater species (in contrast to sea duck species) in the East Atlantic flyway. Based on current knowledge, we suggest that common teal Anas crecca, Eurasian wigeon Mareca penelope and common goldeneye Bucephala clangula represent the best species for testing the application of an AM modelling approach to duck populations in Europe. Applying AM to huntable species with relatively good population data as models for broader implementation represents a cost effect to develop AM on a European flyway scale for ducks, and potentially other waterbirds in the future.
  •  
52.
  • Holopainen, Sari, et al. (författare)
  • Sustainable management of migratory European ducks : finding model species
  • 2018
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Eurasian migratory ducks are a natural resource shared between multiple European countries. Due to lack of flyway-level management and monitoring, there is a risk of “the tragedy of the commons” arising, where populations are overexploited. Effective management may also be hindered by a poor understanding of the factors that limit and regulate migratory populations throughout their flyways, and over time. Following decades of population increase, some European duck populations now show signs of levelling off or even decline, underlining the need for more active management. In Europe, we lack effective common tools to manage duck populations, despite the need and enthusiasm for establishing flyway-level adaptive management (AM) schemes for migratory birds. There are several international legal agreements (e.g. EEC Birds Directive, AEWA) that oblige European countries to sustainably manage migratory birds and their habitats. Although the lack of coordinated demographic and hunting data remains a challenge to sustainable management planning for waterfowl, AM provides a robust decision-making framework even in the presence of uncertainty.We investigate the research and monitoring needs in Europe to successfully apply AM to ducks, and search for possible model species, focusing on freshwater duck species.  Our geographical focus is NW Europe (excluding Russia), the area utilized by ducks in the East-Atlantic flyway. Based on current knowledge and their wide distribution, we suggest that Common Teal Anas crecca, Eurasian Wigeon Mareca penelopeand Common Goldeneye Bucephala clangulawould be the best species for testing the application of an AM modelling approach for ducks in Europe. Applying AM to huntable species with relatively good population data as models for broader implementation represents a cost effective way of starting to develop AM on a European flyway scale for ducks and other harvested waterbirds.
  •  
53.
  • Jönsson, K. Ingemar, 1959-, et al. (författare)
  • Experimentally induced anhydrobiosis in the tardigrade Richtersius coronifer : phenotypic factors affecting survival
  • 2002
  • Ingår i: Journal of Experimental Zoology. - : John Wiley & Sons Inc.. - 0022-104X .- 1097-010X. ; 293:6, s. 578-584
  • Tidskriftsartikel (refereegranskat)abstract
    • The ability of some animal taxa (e.g., nematodes, rotifers, and tardigrades) to enter an ametabolic (cryptobiotic) state is well known. Nevertheless, the phenotypic factors affecting successful anhydrobiosis have rarely been investigated. We report a laboratory study on the effects of body size, reproductive condition, and energetic condition on anhydrobiotic survival in a population of the eutardigrade Richtersius coronifer. Body size and energetic condition interacted in affecting the probability of survival, while reproductive condition had no effect. Large tardigrades had a lower probability of survival than medium-sized tardigrades and showed a positive response in survival to energetic condition. This suggests that energy constrained the possibility for large tardigrades toenter and to leave anhydrobiosis. As a possible alternative explanation for low survival in the largest specimens we discuss the expression of senescence. In line with the view that processes related to anhydrobiosis are connected with energetic costs we documented a decrease in the size of storage cells over a period of anhydrobiosis, showing for the first time that energy is consumed in the process of anhydrobiosis in tardigrades.
  •  
54.
  •  
55.
  •  
56.
  • Koons, D. N., et al. (författare)
  • Drivers of waterfowl population dynamics : from teal to swans
  • 2014
  • Ingår i: Wildfowl. - 0954-6324 .- 2052-6458. ; :Special Issue 4, s. 169-191
  • Tidskriftsartikel (refereegranskat)abstract
    • Waterfowl are among the best studied and most extensively monitored species in the world. Given their global importance for sport and subsistence hunting, viewing and ecosystem functioning, great effort has been devoted since the middle part of the 20th century to understanding both the environmental and demographic mechanisms that influence waterfowl population and community dynamics. Here we use comparative approaches to summarise and contrast our understanding of waterfowl population dynamics across species as short-lived as the teal Anas discors and A. crecca to those such as the swans Cygnus sp. which have long life-spans. Specifically, we focuson population responses to vital rate perturbations across life history strategies, discuss bottom-up and top-down responses of waterfowl populations to global change, and summarise our current understanding of density dependence across waterfowl species. We close by identifying research needs and highlight ways to overcome the challenges of sustainably managing waterfowl populations in the 21st century.
  •  
57.
  • Lacoursière, Jean O., 1958- (författare)
  • A laboratory study of fluid flow and microhabitat selection by larvae of Simulium vittatum (Diptera: Simuliidae)
  • 1992
  • Ingår i: Canadian Journal of Zoology. - 0008-4301 .- 1480-3283. ; 70:3, s. 582-596
  • Tidskriftsartikel (refereegranskat)abstract
    • Microhabitat selection by Simulium vittatum Zetterstedt larvae in a flume was studied at different mainstream velocities on two substrates; a thin flat plate parallel to the flow and a cylinder in cross flow. The results do not support the generally accepted assumptions that simuliid larvae keep within the boundary layer to avoid the direct influence of mainstream current and that they select the fastest velocity available when offered a longitudinal velocity gradient within their tolerance range. Instead, larvae gathered along the zone of boundary layer separation and remained along the stagnation line at the leading point of the cylinder when artificially positioned there. Further, under most conditions, larvae avoided zones of maximum surface shear stress. Larval reaction to hydraulic changes was immediate. It is hypothesized that S. vittatum larvae first scan the velocity profile at the substrate, initially moving toward increasing flow velocity (or water acceleration). They than cue on a steep velocity gradient along the body as part of the processes involved in choosing a location for suspension feeding.
  •  
58.
  •  
59.
  • Lacoursière, Jean O., 1958-, et al. (författare)
  • Use of the continuity principle to evaluate water processing rate of suspension-feeding mosquito larvae
  • 1999
  • Ingår i: Journal of the American Mosquito Control Association. - 8756-971X .- 1943-6270. ; 15:2, s. 228-237
  • Tidskriftsartikel (refereegranskat)abstract
    • Water processing rates of active suspension-feeding larvae of Culiseta morsitans and Cities quinquefasciatus 2nd and 4th instars were estimated through video image analysis of the conical jet flow driving the large recirculation patterns surrounding the organisms. In accordance with the principle of continuity, individual processing rates (PRs) were assessed by averaging a series of consecutive flow rates (Q(x)) defined as the product of the water velocity (U-x) and the associated cross-sectional area (A(x)) along a transect passing through the center of the delineated jet flow. Results clearly show very tight adherence to the principle of continuity. They also demonstrate that, although extreme care must be taken when streamtube delineation is performed, the methodology used can generate reliable assessment of individual processing rates regardless of the instars or species studied. The small coefficient of variation observed in assessing PR at the larval level further underlines the consistency of the method. Significant differences in water processing rates were observed for different species and instars. These could partially be related to body size, head width, and the length of the lateral palatal brushes (LPBs, which are the structures involved in the production of the water jet. Assessment of the jet velocity at the feeding groove level suggests the keg role of LPB beating frequency in the jet intensity, and consequently the magnitude of the processing rate. Analysis of data further indicates that obligate suspension feeders such as Cs. morsitans must sustain a larger flow pattern around the larvae to ensure sufficient particle entrapment than facultative suspension feeders (or even brushers) such as Cs. quinquefasciatus.
  •  
60.
  • Liljebäck, Niklas, et al. (författare)
  • Learning from long time series of harvest and population data : Swedish lessons for European goose management
  • 2021
  • Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research (NKV). - 0909-6396 .- 1903-220X. ; 1, s. 1-10
  • Recension (refereegranskat)abstract
    • Goose management in Europe is faced by multiple challenges, as some species are declining and in need of conservation actions, while other populations have become very abundant, resulting in calls for increased harvest. Sweden has long-term series of harvest data and counts of breeding and autumn-staging geese. We used national data (indices) for greylag goose, bean goose and Canada goose to study shifts in temporal trends and correlative patterns, and to infer possible causal links between harvest and population trends. Our study provides an opportunity to guide management given the data collected within the present monitoring, as well as to suggest improvements for future data collection. The populations of greylag and Canada geese increased in Sweden 1979–2018, but this long-term trend included a recent decrease in the latter species. Bean goose breeding index decreased, whilst staging numbers and harvest varied with no clear long-term trend. For Canada goose, our analysis suggests that harvest may affect population growth negatively. For bean goose and greylag goose we could not detect any effect of harvest on autumn counts the following year. We find that the present data and analysis of coherence may suffice as basis for decisions for the current management situation in Sweden with its rather unspecific goals for greylag (very abundant) and Canada goose (invasive species) populations. However, for management of bean geese, with international concerns of over harvest, data lack crucial information. For future management challenges, with more explicit goals, for all goose species we advocate information that is more precise. Data such as hunting effort, age-structure of goose populations and mark–recapture data to estimate survival and population size, is needed to feed predictive population models guiding future Swedish and European goose management.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 51-60 av 81
Typ av publikation
tidskriftsartikel (42)
konferensbidrag (27)
bokkapitel (6)
rapport (3)
doktorsavhandling (1)
forskningsöversikt (1)
visa fler...
recension (1)
visa färre...
Typ av innehåll
refereegranskat (62)
övrigt vetenskapligt/konstnärligt (10)
populärvet., debatt m.m. (9)
Författare/redaktör
Gunnarsson, Gunnar (28)
Elmberg, Johan, 1960 ... (25)
Pöysä, Hannu (20)
Sjöberg, Kjell (19)
Nummi, Petri (18)
Elmberg, Johan (17)
visa fler...
Gunnarsson, Gunnar, ... (15)
Vought, Lena B. M. (10)
Söderquist, Pär (9)
Jönsson, K. Ingemar, ... (8)
Guillemain, Matthieu (8)
Lacoursière, Jean O. ... (8)
Arzel, Céline (7)
Dessborn, Lisa, 1976 ... (6)
Holopainen, Sari (6)
Månsson, Johan (4)
Fox, Anthony D. (4)
Waldenström, Jonas (4)
Herczeg, Gábor (3)
Jönsson, Ingemar (3)
Champagnon, Jocelyn (3)
Hutton, Stephen. A. (3)
Björklund, Erland (2)
Olsen, Björn (2)
Thulin, Carl-Gustaf (2)
Söderman, Fredrik (2)
Merilä, Juha (2)
Merila, Juha (2)
Lehikoinen, Aleksi (2)
Dessborn, Lisa (2)
Latorre-Margalef, Ne ... (2)
Lacoursière, Jean O. (2)
Svahn, Ola, 1970- (2)
Gessner, Mark O. (2)
Kreisinger, Jakub (2)
Moller, Anders Pape (2)
Ferreira, Veronica (2)
Chauvet, Eric (2)
Tiegs, Scott D. (2)
Risnoveanu, Geta (2)
Dalby, Lars (2)
Hessel, Rebecca (2)
Liljebäck, Niklas (2)
Olsson, Camilla (2)
Väänänen, Veli-Matti (2)
Christensen, Thomas ... (2)
Holm, Thomas Eske (2)
Montras Janer, Teres ... (2)
Mckie, Brendan G. (2)
Giller, Paul S. (2)
visa färre...
Lärosäte
Högskolan Kristianstad (81)
Sveriges Lantbruksuniversitet (9)
Lunds universitet (7)
Umeå universitet (1)
Uppsala universitet (1)
Stockholms universitet (1)
visa fler...
Högskolan i Skövde (1)
Linnéuniversitetet (1)
visa färre...
Språk
Engelska (66)
Svenska (14)
Norska (1)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (81)
Lantbruksvetenskap (6)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy