scholarly journals Environmental drivers of invertebrate population dynamics in Neotropical tank bromeliads

2016 ◽  
Vol 62 (2) ◽  
pp. 229-242 ◽  
Author(s):  
Olivier Dézerald ◽  
Céline Leroy ◽  
Bruno Corbara ◽  
Alain Dejean ◽  
Stanislas Talaga ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Environmental Drivers ◽  
Invertebrate Population ◽  
Tank Bromeliads

scholarly journals Contrasting effects of climate change on seasonal survival of a hibernating mammal

2020 ◽  
Vol 117 (30) ◽  
pp. 18119-18126 ◽  
Author(s):  
Line S. Cordes ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Paul J. CaraDonna ◽  
Dylan Z. Childs ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Life History ◽  
Environmental Conditions ◽  
Temporal Trends ◽  
Life History Strategies ◽  
Environmental Drivers ◽  
Age Classes ◽  
History Of ◽  
Colorado Rocky Mountains

Seasonal environmental conditions shape the behavior and life history of virtually all organisms. Climate change is modifying these seasonal environmental conditions, which threatens to disrupt population dynamics. It is conceivable that climatic changes may be beneficial in one season but result in detrimental conditions in another because life-history strategies vary between these time periods. We analyzed the temporal trends in seasonal survival of yellow-bellied marmots (Marmota flaviventer) and explored the environmental drivers using a 40-y dataset from the Colorado Rocky Mountains (USA). Trends in survival revealed divergent seasonal patterns, which were similar across age-classes. Marmot survival declined during winter but generally increased during summer. Interestingly, different environmental factors appeared to drive survival trends across age-classes. Winter survival was largely driven by conditions during the preceding summer and the effect of continued climate change was likely to be mainly negative, whereas the likely outcome of continued climate change on summer survival was generally positive. This study illustrates that seasonal demographic responses need disentangling to accurately forecast the impacts of climate change on animal population dynamics.

scholarly journals Climatic changes cause synchronous population dynamics and adaptive strategies among coastal hunter-gatherers in Holocene northern Europe

2020 ◽  
pp. 1-16 ◽  
Author(s):  
Erlend Kirkeng Jørgensen ◽  
Petro Pesonen ◽  
Miikka Tallavaara
Keyword(s):  
Population Dynamics ◽  
Environmental Changes ◽  
Environmental Variability ◽  
Temporal Frequency ◽  
Environmental Drivers ◽  
Natural Phenomenon ◽  
Northern Europe ◽  
Human Populations ◽  
Hunter Gatherers ◽  
Human Ecodynamics

Abstract Synchronized demographic and behavioral patterns among distinct populations is a well-known, natural phenomenon. Intriguingly, similar patterns of synchrony occur among prehistoric human populations. However, the drivers of synchronous human ecodynamics are not well understood. Addressing this issue, we review the role of environmental variability in causing human demographic and adaptive responses. As a case study, we explore human ecodynamics of coastal hunter-gatherers in Holocene northern Europe, comparing population, economic, and environmental dynamics in two separate areas (northern Norway and western Finland). Population trends are reconstructed using temporal frequency distributions of radiocarbon-dated and shoreline-dated archaeological sites. These are correlated to regional environmental proxies and proxies for maritime resource use. The results demonstrate remarkably synchronous patterns across population trajectories, marine resource exploitation, settlement pattern, and technological responses. Crucially, the population dynamics strongly correspond to significant environmental changes. We evaluate competing hypotheses and suggest that the synchrony stems from similar responses to shared environmental variability. We take this to be a prehistoric human example of the “Moran effect,” positing similar responses of geographically distinct populations to shared environmental drivers. The results imply that intensified economies and social interaction networks have limited impact on long-term hunter-gatherer population trajectories beyond what is already proscribed by environmental drivers.

scholarly journals Morfologija i ekologija slabo poznatog dinoflagelata Prorocentrum arcuatum (Dinophyceae) iz Medulinskog zaljeva (istočni dio Jadranskog mora)

2017 ◽  
Vol 58 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Sanda Skejić ◽  
Slaven Jozić ◽  
Jacob Larsen ◽  
Olja Vidjak ◽  
Grozdan Kušpilić ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Environmental Drivers ◽  
Natural Conditions ◽  
Sem Images ◽  
Phytoplankton Population ◽  
Narrow Temperature Range ◽  
Physical Conditions ◽  
Field Samples ◽  
General Similarity

The unusual and prolonged occurrence of rare and poorly known dinoflagellate Prorocentrum arcuatum in the phytoplankton of the shallow aquaculture site in Medulin Bay was recorded from July 2013 to October 2014. This enabled us to investigate changes in abundance and environmental drivers of P. arcuatum population dynamics in natural conditions, and to provide first detailed description of P. arcuatum from field samples based on SEM images. During 15 months of observations we also recorded seasonal variability in P. arcuatum cell size. The optimum physical conditions for P. arcuatum proliferation were reached in autumn 2013, during the narrow temperature range between 19.6 oC – 20.4 oC, and salinity between 36.7 - 37.7. Despite the general similarity in physical conditions in autumn 2014, this increase in the abundance of P. arcuatum was not repeated, which might be connected to higher competition due to observed interannual changes in phytoplankton population structure.

Drivers of demography: past challenges and a promise for a changed future

2021 ◽  
pp. 115-130
Author(s):  
Pedro F. Quintana-Ascencio ◽  
Eric S. Menges ◽  
Geoffrey S. Cook ◽  
Johan Ehrlén ◽  
Michelle E. Afkhami
Keyword(s):  
Population Dynamics ◽  
Environmental Variables ◽  
Environmental Drivers ◽  
Factors Affecting ◽  
Future Developments ◽  
Projections And Predictions ◽  
Demographic Modelling ◽  
Experimental Approaches ◽  
Closed Systems ◽  
Metapopulation Models

There is an urgent need to understand how populations and metapopulations respond to shifts in the environment to mitigate the consequences of human actions and global change. Identifying environmental variables/factors affecting population dynamics and the nature of their impacts is fundamental to improve projections and predictions. This chapter examines how environmental drivers, both continuous (stress) and episodic (disturbance), are incorporated in demographic modelling across many types of organisms and environments, using both observational and experimental approaches to characterise drivers. It critically summarises examples of the main approaches and identifies major accomplishments, challenges, and limitations. The chapter points to promising approaches and possible future developments. In the initial sections, models in closed systems without migration among populations are considered. The chapter then focuses on metapopulation models, emphasising the importance of understanding drivers affecting migration and differential extinction among populations. Finally, it concludes with a discussion of some important and general problems associated with assessing how population dynamics may be affected by environmental drivers that are dynamic, nonlinear, and with indirect and/or interacting effects with other drivers..

scholarly journals Environmental drivers of salp Thalia democratica population dynamics from in situ observations

2016 ◽  
Vol 561 ◽  
pp. 189-201 ◽  
Author(s):  
M Pascual ◽  
MG Neubert ◽  
JL Acuña ◽  
AR Solow ◽  
C Dominguez-Carrió ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Environmental Drivers ◽  
In Situ Observations

scholarly journals A simulation framework for evaluating fisheries management decisions using environmental information

2013 ◽  
Vol 70 (4) ◽  
pp. 743-754 ◽  
Author(s):  
Dankert W. Skagen ◽  
Mette Skern-Mauritzen ◽  
Dorothy Dankel ◽  
Katja Enberg ◽  
Olav S. Kjesbu ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Fisheries Management ◽  
Environmental Information ◽  
Environmental Indicators ◽  
Environmental Drivers ◽  
Simulation Framework ◽  
Management Decisions ◽  
Management Scenarios ◽  
Environmental Signals ◽  
Fish Stocks

Abstract Skagen, D. W., Skern-Mauritzen, M., Dankel, D., Enberg, K., Kjesbu, O. S., and Nash, R. D. M. 2013. A simulation framework for evaluating fisheries management decisions using environmental information. – ICES Journal of Marine Science, 70: 743–754. The population dynamics of marine fish stocks are influenced by both physical and biological conditions. Yet, such environmental impacts on stock dynamics, and hence stock production, are rarely included in applied fisheries management. To test the utility of taking ecosystem information into account in management decisions requires efficient tools. We propose a simulation framework for evaluating fisheries management schemes that use environmental information as part of the decision basis. A key feature is to link environmental signals to parameters in functions that define the population dynamics. This allows a direct incorporation of environmental drivers into models of population dynamic processes and emphasizes the need for a quantitative understanding of the influence of environmental drivers on such processes. The utility of the simulation framework is demonstrated through a worked example with different management scenarios, where decisions to increase or decrease the exploitation rely on environmental indicators only, or also on information on stock abundance. In this example, a management that was based on indicators only, without updated measures of the state of the stock itself, failed to respond adequately to changes in stock productivity.

scholarly journals Drivers of large-scale spatial demographic variation in a perennial plant

2020 ◽  
Author(s):  
Gesa Römer ◽  
Ditte M. Christiansen ◽  
Hendrik de Buhr ◽  
Kristoffer Hylander ◽  
Owen R. Jones ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Environmental Factors ◽  
Population Growth ◽  
Spatial Variation ◽  
Population Growth Rate ◽  
Forest Understory ◽  
Environmental Drivers ◽  
Vital Rates ◽  
The Impact

AbstractTo understand how the environment drives spatial variation in population dynamics, we need to assess the effects of a large number of potential drivers on the vital rates (survival, growth and reproduction), and explore these relationships over large geographical areas and long environmental gradients. In this study, we examined the effects of a broad variety of abiotic and biotic environmental factors, including intraspecific density, on the demography of the forest understory herb Actaea spicata between 2017 and 2019 at 40 sites across Sweden, including the northern range margin of its distribution. We assessed the effect of potential environmental drivers on vital rates using generalized linear mixed models (GLMMs), and then quantified the impact of each important driver on population growth rate (λ) using integral projection models (IPMs). Population dynamics of A. spicata were mostly driven by environmental factors affecting survival and growth, such as air humidity, soil depth and forest tree species composition, and thus those drivers jointly determined the realized niche of the species. Soil pH had a strong effect on the flowering probability, while the effect on population growth rate was relatively small. In addition to identifying specific drivers for A. spicata’s population dynamics, our study illustrates the impact that spatial variation in environmental conditions can have on λ. Assessing the effects of a broad range of potential drivers, as done in this study, is important not only to quantify the relative importance of different drivers for population dynamics but also to understand species distributions and abundance patterns.

scholarly journals Nutrient availability and senescence spatially structure the dynamics of a foundation species

2021 ◽  
Vol 119 (1) ◽  
pp. e2105135118
Author(s):  
Tom W. Bell ◽  
David A. Siegel
Keyword(s):  
Population Dynamics ◽  
Physiological Condition ◽  
Regional Scale ◽  
Photosynthetic Pigment ◽  
Terrestrial Ecosystems ◽  
Plant Population ◽  
Environmental Drivers ◽  
Kelp Forests ◽  
Plant Population Dynamics ◽  
Wide Range

Disentangling the roles of the external environment and internal biotic drivers of plant population dynamics is challenging due to the absence of relevant physiological and abundance information over appropriate space and time scales. Remote observations of giant kelp biomass and photosynthetic pigment concentrations are used to show that spatiotemporal patterns of physiological condition, and thus growth and production, are regulated by different processes depending on the scale of observation. Nutrient supply was linked to regional scale (>1 km) physiological condition dynamics, and kelp forest stands were more persistent where nutrient levels were consistently high. However, on local scales (<1 km), internal senescence processes related to canopy age demographics determined patterns of biomass loss across individual kelp forests despite uniform nutrient conditions. Repeat measurements of physiology over continuous spatial fields can provide insights into complex dynamics that are unexplained by the environmental drivers thought to regulate abundance. Emerging remote sensing technologies that provide simultaneous estimates of abundance and physiology can quantify the roles of environmental change and demographics governing plant population dynamics for a wide range of aquatic and terrestrial ecosystems.

scholarly journals Exploring population responses to environmental change when there's never enough data; a factor analytic approach

2017 ◽  
Author(s):  
Bethan J. Hindle ◽  
Mark Rees ◽  
Andy W. Sheppard ◽  
Pedro F. Quintana-Ascencio ◽  
Eric S. Menges ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Latent Variable ◽  
Life History Evolution ◽  
Environmental Drivers ◽  
Time Varying ◽  
Simulation Studies ◽  
Vital Rates ◽  
Time Varying Parameters ◽  
History Evolution

Temporal variability in the environment drives variation in individuals' vital rates, with consequences for population dynamics and life history evolution. Integral projection models (IPMs) are data-driven models widely used to study population dynamics and life history evolution of structured populations in temporally variable environments. However, many data sets have insufficient temporal replication for the environmental drivers of vital rates to be identified with confidence, limiting their use for evaluating population level responses to environmental change. Parameter selection, where the kernel is constructed at each time step by randomly selecting the time-varying parameters from their joint probability distribution, is one approach to including stochasticity in IPMs. We consider a factor analytic (FA) approach for modelling the covariance matrix of time-varying parameters, whereby latent variable(s) describe the covariance among vital rate parameters. This decreases the number of parameters estimated and, where the covariance is positive, the latent variable can be interpreted as a measure of environmental quality. We demonstrate this using simulation studies and two case studies. The simulation studies suggest the FA approach provides similarly accurate estimates of stochastic population growth rate to estimating an unstructured covariance matrix. We demonstrate how the latent parameter can be perturbed to show how selection on reproductive delays in the monocarp Carduus nutans changes under different environmental conditions. We develop a demographic model of the fire dependent herb Eryngium cuneifolium to show how a causal indicator (i.e. a driver of the changes in the environmental quality) can be incorporated with the addition of a single parameter. Using perturbation analyses we determine optimal management strategies for this species. This approach estimates fewer parameters than previous approaches and allows novel eco-evolutionary insights. Predictions on population dynamics and life history evolution under different environmental conditions can be made without necessarily identifying causal factors. Environmental drivers can be incorporated with relatively few parameters, allowing for predictions on how populations will be affected by changes to these drivers.

Daily estimates reveal fine-scale temporal and spatial variation in fish survival across a stream network

2019 ◽  
Vol 76 (8) ◽  
pp. 1446-1458
Author(s):  
Evan S. Childress ◽  
Keith H. Nislow ◽  
Andrew R. Whiteley ◽  
Matthew J. O’Donnell ◽  
Benjamin H. Letcher
Keyword(s):  
Population Dynamics ◽  
Brook Trout ◽  
Low Flow ◽  
Environmental Drivers ◽  
Adult Survival ◽  
Fine Scale ◽  
Vital Rates ◽  
Flow Conditions ◽  
Stream Network ◽  
Spawning Period

Environmental drivers of population vital rates, such as temperature and precipitation, often vary at short time scales, and these fluctuations can have important impacts on population dynamics. However, relationships between survival and environmental conditions are typically modeled at coarse temporal scales, ignoring the role of daily environmental variation in survival. Our goal was to determine the importance of fine-scale temporal variation in survival to population dynamics of stream salmonids. We extended the Cormack–Jolly–Seber model to estimate daily survival rates from seasonal samples of individually marked brook trout (Salvelinus fontinalis) in a stream network. Daily variation in temperature and flow were strongly associated with survival, but relationships varied between juvenile and adult trout and among streams. In all streams, juveniles had higher mortality in warm, low-flow conditions, but in the two larger streams, cold, high-flow conditions also reduced juvenile survival. Adult survival decreased during low flows, particularly in the fall spawning period. Differing survival responses among stream network components to short-term environmental events created shifts in optimal location for maximum survival across life stages, seasons, and years.

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