A5032432193- Wildlife Ecology and Conservation
- Ecology and Vegetation Dynamics Studies
- Animal Ecology and Behavior Studies
- Species Distribution and Climate Change
- Avian ecology and behavior
- Plant and animal studies
- Genetic and phenotypic traits in livestock
- Animal Behavior and Reproduction
- Isotope Analysis in Ecology
- Evolution and Genetic Dynamics
- Ecology and biodiversity studies
- Ecosystem dynamics and resilience
- Fish Ecology and Management Studies
- Genetic diversity and population structure
- Indigenous Studies and Ecology
- Rangeland and Wildlife Management
- Marine Biology and Ecology Research
- Land Use and Ecosystem Services
- Yersinia bacterium, plague, ectoparasites research
- Marine and fisheries research
- Climate variability and models
- Marine and coastal plant biology
- Marine Bivalve and Aquaculture Studies
- Animal Behavior and Welfare Studies
- Evolutionary Game Theory and Cooperation
Norwegian University of Science and Technology
2014-2025
Norwegian Biodiversity Information Centre
2020-2023
University of Groningen
2022
Norwegian Institute for Nature Research
2005-2022
Norwegian Polar Institute
2022
Balancing Act Life cycles are strongly influenced by seasonal and interannual environmental climate events. Such phenological timings likely to shift as our changes, but species exist in communities, not all can be expected concert. Reed et al. (p. 488 ) used long-term data on European great tits reveal how the negative consequences of mismatch buffered: Lower fitness individuals subject mismatch-driven reductions food availability was balanced competition. Thus, overall, population is...
All Together Now Environmental drivers, such as extreme weather events, impact population dynamics and can synchronize across populations within a species. Given that many species depend on similar resources, events might also be expected to species, but the complexity of multispecies communities makes it difficult reveal potential drivers in common. Hansen et al. (p. 313 ) took advantage simplicity year-round community high-arctic island Spitsbergen test for presence synchrony. Population...
A major question in ecology is how age-specific variation demographic parameters influences population dynamics. Based on long-term studies of growing populations birds and mammals, we analyze dynamics by using fluctuations the total reproductive value population. This enables us to account for random age distribution. The influence environmental stochasticity a species decreased with generation time. Variation contributions stochastic components was correlated position along slow-fast...
Estimation of intra- and interspecific interactions from time-series on species-rich communities is challenging due to the high number potentially interacting species pairs. The previously proposed sparse model overcomes this challenge by assuming that most pairs do not interact. We propose an alternative does assume any are necessarily zero, but summarizes influences individual a small community-level drivers. drivers defined as linear combinations abundances, they may thus represent e.g....
Summary 1. Studies of seasonality in ecological diversity rarely extend over more than a few years, and studies seasonal have explicitly investigated the influence environmental factors on community composition, especially tropical communities. 2. Our 10 years monthly sampling Amazonian Ecuador yielded 20 996 individuals 137 fruit‐feeding butterfly species. Seasonal cycles rainfall drive annual species similarity. Undetermined processes operating most strongly during dry season maintain high...
Abstract Extreme climate events often cause population crashes but are difficult to account for in population-dynamic studies. Especially long-lived animals, density dependence and demography may induce lagged impacts of perturbations on growth. In Arctic ungulates, extreme rain-on-snow ice-locked pastures have led severe crashes, indicating that increasingly frequent could destabilize populations. Here, using empirically parameterized, stochastic models High-Arctic wild reindeer, we show...
Abstract There is large interspecific variation in the magnitude of population fluctuations, even among closely related species. The factors generating this are not well understood, primarily because challenges separating relative impact size from fluctuations environment. Here, we show using demographic data 13 bird populations that magnitudes mainly driven by stochastic Regulation towards an equilibrium occurs through density-dependent mortality. At small sizes, dynamics environment-driven...
The world is spatially autocorrelated. Both abiotic and biotic properties are more similar among neighboring than distant locations, their temporal co‐fluctuations also decrease with distance. P. A. Moran realized the ecological importance of such ‘spatial synchrony’ when he predicted that isolated populations subject to identical log‐linear density‐dependent processes should have same correlation in fluctuations abundance as environmental noise. contribution from correlated weather...
Abstract 1. The availability and quantity of observational species occurrence records have greatly increased due to technological advancements the rise online portals, such as Global Biodiversity Information Facility (GBIF), coalescing from multiple datasets. It is well‐established that are biased in time, space taxonomy, but whether these datasets differ relation origin not been assessed. If biases specific different types datasets, relative contribution changed over shifting will...
Mountains are particularly exposed to climate change, and empirical studies have shown that montane bird species highly sensitive the ongoing changes. Modelling mortality risks under climatic variation will give insight into species‐specific sensitivity. Willow ptarmigan Lagopus l. lagopus is a common resident in many northern alpine ecosystems, with an important role predator–prey dynamics. moult white feathers during autumn, which provides camouflage winter snow. With shorter periods of...
Theoretical analyses have shown that the spatial scaling of environmental autocorrelation, strength density regulation, and dispersal individuals determine synchrony in population fluctuations. By modeling separate effects stochasticity, demographic we estimate component is due to stochasticity dynamics roe deer (Capreolus capreolus) Norway. The estimated noise was ∼200 km. An examination how different weather variables influenced indicated snow depth major variable affecting fluctuations,...
Climate change will affect the population dynamics of many species, yet consequences for long-term persistence populations are poorly understood. A major reason this is that density-dependent feedback effects caused by fluctuations in size considered independent stochastic variation environment. We show an interplay between winter temperature and density can influence a small passerine under global warming. Although warmer winters favor increased mean size, cause local to be less buffered...
The 'Moran effect' predicts that dynamics of populations a species are synchronized over similar distances as their environmental drivers. Strong population synchrony reduces viability, but spatial heterogeneity in density dependence, the environment, or its ecological responses may decouple space, preventing extinctions. How such buffers impacts global change on large-scale is not well studied. Here, we show spatially autocorrelated fluctuations annual winter weather synchronize wild...
Understanding the variation in selection pressure on key life-history traits is crucial our rapidly changing world. Density rarely considered as a selective agent. To study its importance, we partition phenotypic fluctuating environments into components representing population growth rate at low densities and strength of density dependence, using new stochastic modelling framework. We analysed number eggs laid per season small song-bird, great tit, found balancing favouring large clutch...
1. Synchronous fluctuations of geographically separated populations are in general explained by the Moran effect, i.e. a common influence on local population dynamics environmental variables that correlated space. Empirical support for such effect has been difficult to provide, mainly due problems separating out effects dynamics, demographic stochasticity and dispersal also spatial scaling processes. Here we generalize decomposing autocorrelation function size great tit Parus major blue...
Summary Development of population projections requires estimates observation error, parameters characterizing expected dynamics such as the specific growth rate and form density regulation, influence stochastic factors on dynamics, quantification uncertainty in parameter estimates. Here we construct a Population Prediction Interval (PPI) based Bayesian state space modelling future 28 reintroduced ibex populations Switzerland that have been censused for up to 68 years. Our aim is examine...
1. Geographic gradients in population dynamics may occur because of spatial variation resources that affect the deterministic components (i.e. carrying capacity, specific growth rate at small densities or strength density regulation) effects environmental stochasticity. To evaluate these, we used a hierarchical Bayesian approach to estimate parameters characterizing and stochastic influences on eight species ducks (mallard, northern pintail, blue-winged teal, gadwall, shoveler, American...
1 The aim of the present study is to model stochastic variation in size five populations great tit Parus major Netherlands, using a combination individual-based demographic data and time series population fluctuations. We will examine relative contribution density-dependent effects, climate winter food on local dynamics as well number immigrants. 2 Annual changes were strongly affected by temporal recruits produced locally individuals recruited from one breeding season next was mainly...
We develop an integrated population model for Svalbard reindeer Rangifer tarandus platyrhynchus , and demonstrate how this type of can be used to extract more information from the data separate different sources variability in estimates. Our combines individual mark–recapture with counts harvesting within a Bayesian framework, accounts observation error, environmental demographic stochasticity, age structure. From we obtain annual estimates age‐specific size, survival fecundity. The provides...
Despite the importance of understanding effects tropical seasonality on ecological diversity, few studies have investigated influence environmental factors seasonal community composition, and even fewer use standardized sampling robust analytical methods that are directly comparable. Our 104 months in Costa Rican lowland rainforest yielded 12 757 individuals 106 fruit‐feeding butterfly species demonstrated biannual cycles but similarity showed an annual cycle peaked driest months. We found...
Abstract Aim Forest fragmentation is among the principal causes of global biodiversity loss, yet how it affects mutualistic interactions between plants and animals at large spatial scale poorly understood. In particular, tropical forest regeneration depends on animal‐mediated seed dispersal, but seed‐dispersing face rapid decline due to defaunation. Here, we assess influences pairwise 407 disperser 1,424 tree species in a highly fragmented hotspot. Location Atlantic Forest, South America....
Climate change is most rapid in the Arctic, posing both benefits and challenges for migratory herbivores. However, population-dynamic responses to climate are generally difficult predict, due concurrent changes other trophic levels. Migratory species also exposed contrasting trends density regimes over annual cycle. Thus, determining how impacts their population dynamics requires an understanding of weather directly or indirectly (through interactions carryover effects) affects reproduction...
1. A central question in ecology is to separate the relative contribution of density dependence and stochastic influences annual fluctuations population size. Here we estimate deterministic components dynamics different European populations white stork Ciconia ciconia. We then examined whether changes size was related climate during breeding period (the 'tap hypothesis' sensu Saether, Sutherland & Engen (2004, Advances Ecological Research, 35, 185 209) or nonbreeding period, especially...
We examined whether differences in life-history characteristics can explain interspecific variation stochastic population dynamics nine marine fish species living the Barents Sea system. After observation errors estimates were accounted for, temporal variability natural mortality rate, annual recruitment, and growth rate was negatively related to generation time. Mean lower long-lived than short-lived species. Thus, important species-specific of position along slow-fast continuum variation....