scholarly journals Disentangling environmental drivers of circadian metabolism in desert-adapted mice

2021 ◽  
Vol 224 (18) ◽  
Author(s):  
Jocelyn P. Colella ◽  
Danielle M. Blumstein ◽  
Matthew D. MacManes
Keyword(s):  
Environmental Change ◽  
Environmental Conditions ◽  
Environmental Drivers ◽  
Complex Phenotype ◽  
Metabolic Phenotyping ◽  
New Methods ◽  
Physiological Adaptations ◽  
Peromyscus Eremicus ◽  
Abiotic Controls ◽  
Cool Conditions

ABSTRACT Metabolism is a complex phenotype shaped by natural environmental rhythms, as well as behavioral, morphological and physiological adaptations. Metabolism has been historically studied under constant environmental conditions, but new methods of continuous metabolic phenotyping now offer a window into organismal responses to dynamic environments, and enable identification of abiotic controls and the timing of physiological responses relative to environmental change. We used indirect calorimetry to characterize metabolic phenotypes of the desert-adapted cactus mouse (Peromyscus eremicus) in response to variable environmental conditions that mimic their native environment versus those recorded under constant warm and constant cool conditions, with a constant photoperiod and full access to resources. We found significant sexual dimorphism, with males being more prone to dehydration than females. Under circadian environmental variation, most metabolic shifts occurred prior to physical environmental change and the timing was disrupted under both constant treatments. The ratio of CO2 produced to O2 consumed (the respiratory quotient) reached greater than 1.0 only during the light phase under diurnally variable conditions, a pattern that strongly suggests that lipogenesis contributes to the production of energy and endogenous water. Our results are consistent with historical descriptions of circadian torpor in this species (torpid by day, active by night), but reject the hypothesis that torpor is initiated by food restriction or negative water balance.

scholarly journals Disentangling environmental drivers of circadian metabolism in desert-adapted mice

2020 ◽  
Author(s):  
Jocelyn P. Colella ◽  
Danielle M. Blumstein ◽  
Matthew D. MacManes
Keyword(s):  
Environmental Conditions ◽  
Metabolic Responses ◽  
Environmental Drivers ◽  
Metabolic Phenotyping ◽  
Physiological Adaptations ◽  
Cold Tolerant ◽  
Environmental Transitions ◽  
Summary Statement ◽  
Flow Through ◽  
Peromyscus Eremicus

ABSTRACTMetabolism is a complex phenotype shaped by natural environmental rhythms, as well as behavioral, morphological, and physiological adaptations. Although historically studied under constant environmental conditions, continuous metabolic phenotyping through environmental transitions now offers a window into the physiological responses of organisms to changing environments. Here, we use flow-through respirometry to compare metabolic responses of the desert-adapted cactus mouse (Peromyscus eremicus) between diurnally variable and constant environmental conditions. We contrast metabolic responses to circadian cycles in photoperiod, temperature, and humidity, against those recorded under constant hot-and-dry and constant cold-and-wet conditions. We found significant sexual dimorphism in metabolic responses, despite no measurable difference in body weight. Males seem to be more heat tolerant and females more cold tolerant. Under circadian environmental cycling, the ratio of CO2 produced to O2 consumed (the respiratory quotient or respiratory exchange ratio) reached greater than one, a pattern that strongly suggests that lipogenesis is contributing to the production of energy and endogenous water in this species. This hypothesis is consistent with the results of previous dehydration experiments in this species, which documented significant weight loss in response to dehydration, without other physiological impairment. Our results are also consistent with historical descriptions of circadian torpor in this species (torpid by day, active by night), but reject the hypothesis that this pattern is driven by food restriction or negative water balance, as both resources were available to animals throughout the experiments.SUMMARY STATEMENTContinuous metabolic phenotyping of desert-adapted cactus mice (Peromyscus eremicus) identifies significant metabolic differences between the sexes and circadian patterning consistent with lipogenesis and environmental entrainment.

scholarly journals Understanding the critical rate of environmental change for ecosystems, cyanobacteria as an example

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253003
Author(s):  
Bregje van der Bolt ◽  
Egbert H. van Nes
Keyword(s):  
Environmental Change ◽  
Environmental Conditions ◽  
Environmental Variability ◽  
Initial Conditions ◽  
Gradual Increase ◽  
Environmental Drivers ◽  
Critical Rate ◽  
Rates Of Change ◽  
Rapid Environmental Change ◽  
Fast Rates

Recently it has been show that in some ecosystems fast rates of change of environmental drivers may trigger a critical transition, whereas change of the same magnitude but at slower rates would not. So far, few studies describe this phenomenon of rate-induced tipping, while it is important to understand this phenomenon in the light of the ongoing rapid environmental change. Here, we demonstrate rate-induced tipping in a simple model of cyanobacteria with realistic parameter settings. We explain graphically that there is a range of initial conditions at which a gradual increase in environmental conditions can cause a collapse of the population, but only if the change is fast enough. In addition, we show that a pulse in the environmental conditions can cause a temporary collapse, but that is dependent on both the rate and the duration of the pulse. Furthermore, we study whether the autocorrelation of stochastic environmental conditions can influence the probability of inducing rate-tipping. As both the rate of environmental change, and autocorrelation of the environmental variability are increasing in parts of the climate, the probability for rate-induced tipping to occur is likely to increase. Our results imply that, even though the identification of rate sensitive ecosystems in the real world will be challenging, we should incorporate critical rates of change in our ecosystem assessments and management.

Social Change and Psychological Change in Rural Mali

2016 ◽  
Vol 52 (7) ◽  
pp. 965-981 ◽  
Author(s):  
Carmi Schooler ◽  
Leslie J Caplan ◽  
Pakuy Pierre Mounkoro ◽  
Chiaka Diakité
Keyword(s):  
Social Change ◽  
Environmental Change ◽  
Environmental Conditions ◽  
Economic Hardship ◽  
Psychological Change ◽  
Self Confidence ◽  
Personality Stability ◽  
Psychological Reaction ◽  
Using Data ◽  
Over Time

We examine the effects of socio-environmental change on personality in Mali in three ways, using data from a longitudinal two-wave (1994, 2004) survey conducted in rural Mali. Firstly, we compare the between-wave personality stability of Anxiety, Self-confidence, Mastery/Fatalism, and Authoritarianism with that in USA, Japan, Poland, and Ukraine. Secondly, we examine socio-economic hardship and political instability in pre-industrial Mali. Thirdly, we examine patterns of psychological reaction to political and social change during the study period. Our findings have implications for comparisons and generalizations across times and cultures about the contribution of socio-environmental conditions to over-time change in personality.

scholarly journals Three representative UK moorland soils show differences in decadal release of dissolved organic carbon in response to environmental change

2011 ◽  
Vol 8 (12) ◽  
pp. 3661-3675 ◽  
Author(s):  
M. I. Stutter ◽  
D. G. Lumsdon ◽  
A. P. Rowland
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Environmental Change ◽  
Soil Properties ◽  
Process Models ◽  
Environmental Drivers ◽  
Specific Response ◽  
Soil C ◽  
Doc Concentration ◽  
Mineral Soils

Abstract. Moorland carbon reserves in organo-mineral soils may be crucial to predicting landscape-scale variability in soil carbon losses, an important component of which is dissolved organic carbon (DOC). Surface water DOC trends are subject to a range of scaling, transport and biotic processes that disconnect them from signals in the catchment's soils. Long-term soil datasets are vital to identify changes in DOC release at source and soil C depletion. Here we show, that moorland soil solution DOC concentrations at three key UK Environmental Change Network sites increased between 1993–2007 in both surface- and sub- soil of a freely-draining Podzol (48 % and 215 % increases in O and Bs horizons, respectively), declined in a gleyed Podzol and showed no change in a Peat. Our principal findings were that: (1) considerable heterogeneity in DOC response appears to exist between different soils that is not apparent from the more consistent observed trends for streamwaters, and (2) freely-draining organo-mineral Podzol showed increasing DOC concentrations, countering the current scientific focus on soil C destabilization in peats. We discuss how the key solubility controls on DOC associated with coupled physico-chemical factors of ionic strength, acid deposition recovery, soil hydrology and temperature cannot readily be separated. Yet, despite evidence that all sites are recovering from acidification the soil-specific responses to environmental change have caused divergence in soil DOC concentration trends. The study shows that the properties of soils govern their specific response to an approximately common set of broad environmental drivers. Key soil properties are indicated to be drainage, sulphate and DOC sorption capacity. Soil properties need representation in process-models to understand and predict the role of soils in catchment to global C budgets. Catchment hydrological (i.e. transport) controls may, at present, be governing the more ubiquitous rises in river DOC concentration trends, but soil (i.e. source) controls provide the key to prediction of future C loss to waters and the atmosphere.

scholarly journals The effects of population synchrony, life history, and access constraints on benefits from fishing portfolios

2020 ◽  
Author(s):  
Kiva L. Oken ◽  
André E Punt ◽  
Daniel S. Holland
Keyword(s):  
Environmental Conditions ◽  
Life Histories ◽  
Oncorhynchus Tshawytscha ◽  
Environmental Drivers ◽  
Management Options ◽  
Population Synchrony ◽  
Natural Systems ◽  
Advantages And Disadvantages ◽  
Interannual Fluctuations ◽  
Short Time

Natural resources often exhibit large interannual fluctuations in productivity driven by shifting environmental conditions, and this translates to high variability in the revenue resource users can earn. However, users can dampen this variability by harvesting a portfolio of resources. In the context of fisheries, this means targeting multiple populations, though the ability to actually build diverse fishing portfolios is often constrained by the costs and availability of fishing permits. These constraints are generally intended to prevent overcapitalization of the fleet and ensure populations are fished sustainably. As linked human-natural systems, both ecological and fishing dynamics influence the specific advantages and disadvantages of increasing the diversity of fishing portfolios. Specifically, a portfolio of synchronous populations with similar responses to environmental drivers should reduce revenue variability less than a portfolio of asynchronous populations with opposite responses. We built a bioeconomic model characterized by the Dungeness crab (Metacarcinus magister), Chinook salmon (Oncorhynchus tshawytscha), and groundfish fisheries in the California Current, and used it to explore the influence of population synchrony and permit access on revenue patterns. As expected, synchronous populations reduced revenue variability less than asynchronous populations, but only for portfolios including crab and salmon. Synchrony with longer-lived groundfish populations was not important because environmentally-driven changes in groundfish early life survival were mediated by growth and natural mortality over the full population age structure, and overall biomass was relatively stable across years. Thus, building a portfolio of diverse life histories can buffer against the impacts of extremely poor environmental conditions over short time scales, though not for long-term declines. Increasing access to all permits generally led to increased revenue stability and decreased inequality of the fleet, but also resulted in less revenue earned by an individual from a given portfolio because more vessels shared the available biomass. This means managers are faced with a tradeoff between the average revenue individuals earn and the risk those individuals accept. These results illustrate the importance of considering connections between social and ecological dynamics when evaluating management options that constrain or facilitate fishers’ ability to diversify their fishing.

scholarly journals Ecological specialization, variability in activity patterns and response to environmental change

2018 ◽  
Vol 14 (6) ◽  
pp. 20180115 ◽  
Author(s):  
Talisin T. Hammond ◽  
Rupert Palme ◽  
Eileen A. Lacey
Keyword(s):  
Environmental Change ◽  
Environmental Conditions ◽  
Phenotypic Variability ◽  
Activity Patterns ◽  
Temporal Patterns ◽  
Past Century ◽  
Ambient Conditions ◽  
Ecological Specialization ◽  
Sympatric Populations ◽  
Individual Level

Differences in temporal patterns of activity can modulate the ambient conditions to which organisms are exposed, providing an important mechanism for responding to environmental change. Such differences may be particularly relevant to ecological generalists, which are expected to encounter a wider range of environmental conditions. Here, we compare temporal patterns of activity for partially sympatric populations of a generalist (the lodgepole chipmunk, Tamias speciosus ) and a more specialized congener (the alpine chipmunk, Tamias alpinus ) that have displayed divergent responses to the past century of environmental change. Although mean activity budgets were similar between species, analyses of individual-level variation in locomotion revealed that T. alpinus exhibited a narrower range of activity patterns than T . speciosus . Further analyses revealed that T. alpinus was more active earlier in the day, when temperatures were cooler, and that activity patterns for both species changed with increased interspecific co-occurrence. These results are consistent with the greater responsiveness of T. alpinus to changes in environmental conditions. In addition to highlighting the utility of accelerometers for collecting behavioural data, our findings add to a growing body of evidence, suggesting that the greater phenotypic variability displayed by ecological generalists may be critical to in situ responses to environmental change.

Absolute Dating of the Virje and Hlebine Sites

2021 ◽  
pp. 92-100
Author(s):  
Katarina Botić
Keyword(s):  
Environmental Change ◽  
Bayesian Model ◽  
Radiocarbon Dating ◽  
Iron Formation ◽  
Iron Production ◽  
Formation Processes ◽  
Residential Areas ◽  
Ams Radiocarbon Dating ◽  
Absolute Dating ◽  
Cool Conditions

In this chapter the results of AMS radiocarbon dating of 26 charcoal samples from four sites are discussed. The primary aim was to explore the scope of (dis)continuity of temporally and functionally interconnected types of sites (settlement and iron production workshop). A Bayesian model was created based on the acquired data from excavated sites with three sequences in the model determined. The results show great accordance with the archaeologically based data, with some exceptions that are most probably a result of modelling strategy used. Contemporaneity of all four sites is mostly attested with a possible and very short temporal hiatus around AD 600. Occupation of workshop and residential areas at that time or slightly after may have been linked to the globally attested environmental change during the Bond 1 event when dry and cool conditions prevailed and which could have had an impact on bog iron formation processes.

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 Covariation of metabolic rates and cell size in coccolithophores

2015 ◽  
Vol 12 (15) ◽  
pp. 4665-4692 ◽  
Author(s):  
G. Aloisi
Keyword(s):  
Growth Rate ◽  
Environmental Change ◽  
Cell Size ◽  
Environmental Conditions ◽  
Laboratory Experiments ◽  
Opposite Effect ◽  
Cell Structure ◽  
Metabolic Rates ◽  
The Future ◽  
Phytoplankton Group

Abstract. Coccolithophores are sensitive recorders of environmental change. The size of their coccosphere varies in the ocean along gradients of environmental conditions and provides a key for understanding the fate of this important phytoplankton group in the future ocean. But interpreting field changes in coccosphere size in terms of laboratory observations is hard, mainly because the marine signal reflects the response of multiple morphotypes to changes in a combination of environmental variables. In this paper I examine the large corpus of published laboratory experiments with coccolithophores looking for relations between environmental conditions, metabolic rates and cell size (a proxy for coccosphere size). I show that growth, photosynthesis and, to a lesser extent, calcification covary with cell size when pCO2, irradiance, temperature, nitrate, phosphate and iron conditions change. With the exception of phosphate and temperature, a change from limiting to non-limiting conditions always results in an increase in cell size. An increase in phosphate or temperature (below the optimum temperature for growth) produces the opposite effect. The magnitude of the coccosphere-size changes observed in the laboratory is comparable to that observed in the ocean. If the biological reasons behind the environment–metabolism–size link are understood, it will be possible to use coccosphere-size changes in the modern ocean and in marine sediments to investigate the fate of coccolithophores in the future ocean. This reasoning can be extended to the size of coccoliths if, as recent experiments are starting to show, coccolith size reacts to environmental change proportionally to coccosphere size. The coccolithophore database is strongly biased in favour of experiments with the coccolithophore Emiliania huxleyi (E. huxleyi; 82 % of database entries), and more experiments with other species are needed to understand whether these observations can be extended to coccolithophores in general. I introduce a simple model that simulates the growth rate and the size of cells forced by nitrate and phosphate concentrations. By considering a simple rule that allocates the energy flow from nutrient acquisition to cell structure (biomass) and cell maturity (biological complexity, eventually leading to cell division), the model is able to reproduce the covariation of growth rate and cell size observed in laboratory experiments with E. huxleyi when these nutrients become limiting. These results support ongoing efforts to interpret coccosphere and coccolith size measurements in the context of climate change.

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