Publikasjoner
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2022
Forfattere
Gunnhild SøgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Roberto Guidetti Łukasz Kaczmarek Milena Roszkowska Terje Meier Tommy Prestø K. Ingemar Jönsson James David Mervyn Speed Elisabeth Stur Ivar Gjerde Lasse Topstad Kristian Hassel Torbjørn EkremSammendrag
Background: Tardigrades are common in most habitats, however few studies have focusedon large faunistic survey, specifically on tardigrade diversity in forests. Up to now, only 61 species have been recorded in different types of forest in Norway with an additional 25 found in limnic environments in forests. Although little is known about the ecological preferences of many species, previous studies have found that tardigrade diversity and community composition are significantly affected by ecological variables. In this study we associate georeferenced tardigrade species records with forest type, substrate type and substrate composition in order to see if tardigrade diversity and species communities can be associated with ecological characteristics of Norwegian forests. Methods: In total 390 moss, lichen and litter samples were collected from 12 forests in central and southern Norway in the summers of 2017 and 2018 and later stored in paper envelopes. For the identification modern literature and keys for specific genera and groups of species were used. For statistical analyses, moss and lichen substrate of each sample was classified according to the main species, life form, growth forms and habitat of substrate and associated with each tardigrade identification and sample metadata. Results: A total of 17 407 specimens were identified, encompassing in total 132 species (including some new species). Species richness increases with precipitation, but does not change with temperature or precipitation seasonality. The distribution of species richness between life forms and forest types showed considerable variation within and among the variables. Disregarding variables with low sample numbers, among life forms only acrocarpous moss samples appeared to deviate with respect to species richness, containing less species than substrates with other life forms. Conclusions: Tardigrades in Norwegian forest are extremely abundant, frequent and diverse. Moreover, it appears that that certain species and/or entire communities prefer specific microhabitats.
Sammendrag
Population densities of several cervid species have increased in recent decades in North America and Europe, and cervids frequently eat and damage agricultural crops. Competition and depletion of natural food resources are the main mechanisms for the density-dependent decline in vital rates of large herbivores. The extent to which access to agricultural crops can buffer density effects in cervid populations, however, is unknown. Agricultural grasslands cover more than a third of the European agricultural area, and red deer (Cervus elaphus) use these grasslands in many European countries. Over the past few decades, such grasslands have been subject to management intensification (with renewal and fertilization) in some areas and abandonment (no longer being harvested) in other areas. We used generalized linear mixed-effects models to examine the development of body masses of red deer in Norway during a period of population density increase in 16 local management units with different availability of cultivated grasslands (0.87–6.44%) in a region with active management of grasslands (Tingvoll, n = 5,780, 2000–2019) and a region with ongoing abandonment (Hitra, n = 10,598, 2007–2020). There was a consistent decline in the body mass of red deer linked to increased population density in both regions. A higher proportion of agricultural grassland was linked to higher body mass and lower density effects in both sexes and across all age classes. There is a link between body mass, survival, and reproduction. Therefore, the buffering of density effects of access to agricultural crops will fuel cervid population growth and lead to less natural regulation of abundance, making it more difficult to control dense cervid populations by harvesting.
Forfattere
Erling MeisingsetSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
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Sammendrag
I denne rapporten viser vi at jegerrapporterte data gir mulighet for robust bestandsestimering av hjort basert på modellgenererte populasjonsforløp og derved mulighet for framskriving av bestandsutvikling som funksjon av jaktuttak. Tidsseriedataene, populasjonsmodellen og metoden for sammenstilling definerer til sammen en estimeringsmodell. Med utgangspunkt i data fra kommunene Averøy, Tingvoll, Surnadal og Sunndal i Møre og Romsdal viser vi hvordan en slik estimeringsmodell kan brukes til å få robuste anslag for størrelse og sammensetning av hjortebestandene på lokalt nivå.
Forfattere
Erling MeisingsetSammendrag
Det er ikke registrert sammendrag
Forfattere
Erling MeisingsetSammendrag
Det er ikke registrert sammendrag
Forfattere
Erling MeisingsetSammendrag
Det er ikke registrert sammendrag