scholarly journals Shifts in the relative fitness contributions of fecundity and survival in variable and changing environments

2021 ◽  
Vol 224 (Suppl 1) ◽  
pp. jeb228031
Author(s):  
Lauren B. Buckley ◽  
Sean D. Schoville ◽  
Caroline M. Williams
Keyword(s):  
Environmental Conditions ◽  
Energy Use ◽  
Environmental Gradients ◽  
Relative Fitness ◽  
Relative Importance ◽  
Fitness Components ◽  
Climate Variability And Change ◽  
Short Term ◽  
Climate Gradients ◽  
Recent Climate

ABSTRACTOrganisms respond to shifts in climate means and variability via distinct mechanisms. Accounting for these differential responses and appropriately aggregating them is central to understanding and predicting responses to climate variability and change. Separately considering fitness components can clarify organismal responses: fecundity is primarily an integrated, additive response to chronic environmental conditions over time via mechanisms such as energy use and acquisition, whereas survival can be strongly influenced by short-term, extreme environmental conditions. In many systems, the relative importance of fecundity and survival constraints changes systematically along climate gradients, with fecundity constraints dominating at high latitudes or altitudes (i.e. leading range edges as climate warms), and survival constraints dominating at trailing range edges. Incorporating these systematic differences in models may improve predictions of responses to recent climate change over models that assume similar processes along environmental gradients. We explore how detecting and predicting shifts in fitness constraints can improve our ability to forecast responses to climate gradients and change.

scholarly journals Coherent synthesis of genomic associations with phenotypes and home environments

2016 ◽  
Author(s):  
Jesse R. Lasky ◽  
Brenna R. Forester ◽  
Matthew Reimherr
Keyword(s):  
Local Adaptation ◽  
Environmental Gradients ◽  
Common Garden ◽  
Relative Fitness ◽  
Home Environments ◽  
Climate Gradients ◽  
A Genome ◽  
Fitness Tradeoffs ◽  
Common Garden Experiments ◽  
Diverse Data

Local adaptation is often studied via 1) multiple common garden experiments comparing performance of genotypes in different environments and 2) sequencing genotypes from multiple locations and characterizing geographic patterns in allele frequency. Both approaches aim to characterize the same pattern (local adaptation), yet the complementary information from each has not yet been coherently integrated. Here, we develop a genome-wide association model of genotype interactions with continuous environmental gradients (G×E), i.e. reaction norms. We present an approach to impute relative fitness, allowing us to coherently synthesize evidence from common garden and genome-environment associations. Our approach identifies loci exhibiting environmental clines where alleles are associated with higher fitness in home environments. Simulations show our approach can increase power to detect loci causing local adaptation. In a case study on Arabidopsis thaliana, most identified SNPs exhibited home allele advantage and fitness tradeoffs along climate gradients, suggesting selective gradients can maintain allelic clines. SNPs exhibiting G×E associations with fitness were enriched in genic regions, putative partial selective sweeps, and associations with an adaptive phenotype (flowering time plasticity). We discuss extensions for situations where only adaptive phenotypes other than fitness are available. Many types of data may point toward the loci underlying G×E and local adaptation; coherent models of diverse data provide a principled basis for synthesis.

scholarly journals Divergent long- and short-term responses to environmental gradients in specific leaf area of grassland species

2021 ◽  
Vol 130 ◽  
pp. 108058
Author(s):  
Zhaogang Liu ◽  
Ning Dong ◽  
Hongxiang Zhang ◽  
Ming Zhao ◽  
Tingting Ren ◽  
...  
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Environmental Gradients ◽  
Short Term ◽  
Grassland Species

scholarly journals Short term variations of tracer transit speed on alpine glaciers

2010 ◽  
Vol 4 (3) ◽  
pp. 381-396 ◽  
Author(s):  
M. A. Werder ◽  
T. V. Schuler ◽  
M. Funk
Keyword(s):  
Drainage System ◽  
Relative Importance ◽  
Short Term ◽  
Diurnal Variability ◽  
Alpine Glacier ◽  
Two Component ◽  
Transit Speed ◽  
Underlying Processes ◽  
Diurnal Maximum ◽  
Tracer Experiments

Abstract. We first present the results of a series of tracer experiments conducted on an alpine glacier (Gornergletscher, Switzerland) over a diurnal discharge cycle. For these injections, a moulin was used into which an ice marginal lake was draining, providing a relatively constant discharge. The measured tracer transit speeds show two diurnal maxima and minima. These findings are qualitatively different to existing observations from two series of injections conducted at Unteraargletscher (Switzerland) using a moulin fed by supraglacial meltwater having a high diurnal variability, which displayed one diurnal maximum and minimum. We then develop and use a simple two-component model of the glacier drainage system, comprising a moulin and a channel element, to simulate the measured transit speeds for all three injection series. The model successfully reproduces all the observations and shows that the same underlying processes can produce the qualitatively different behaviour depending on the different moulin input discharge regimes. Using the model, we assess the relative importance of the different measurement quantities, show that frequent measurements of moulin input discharge are indispensable and propose an experiment design to monitor the development of the drainage system over several weeks.

scholarly journals The Impact of Economic Growth, Trade Openness and Technological Progress on Renewable Energy Use in Organization for Economic Co-Operation and Development Countries

2021 ◽  
Author(s):  
Md. Mahmudul Alam ◽  
Wahid Murad
Keyword(s):  
Economic Growth ◽  
Renewable Energy ◽  
Least Squares ◽  
Technological Progress ◽  
Energy Use ◽  
Trade Openness ◽  
Oecd Countries ◽  
Ordinary Least Squares ◽  
Short Term

This study investigates the short-term and long-term impacts of economic growth, trade openness and technological progress on renewable energy use in Organization for Economic Co-operation and Development (OECD) countries. Based on a panel data set of 25 OECD countries for 43 years, we used the autoregressive distributed lag (ARDL) approach and the related intermediate estimators, including pooled mean group (PMG), mean group (MG) and dynamic fixed effect (DFE) to achieve the objective. The estimated ARDL model has also been checked for robustness using the two substitute single equation estimators, these being the dynamic ordinary least squares (DOLS) and fully modified ordinary least squares (FMOLS). Empirical results reveal that economic growth, trade openness and technological progress significantly influence renewable energy use over the long-term in OECD countries. While the long-term nature of dynamics of the variables is found to be similar across 25 OECD countries, their short-term dynamics are found to be mixed in nature. This is attributed to varying levels of trade openness and technological progress in OECD countries. Since this is a pioneer study that investigates the issue, the findings are completely new and they make a significant contribution to renewable energy literature as well as relevant policy development.

scholarly journals Plant diversity in sedimentary DNA obtained from high-latitude (Siberia) and high-elevation lakes (China)

2020 ◽  
Vol 8 ◽  
Author(s):  
Kathleen Stoof-Leichsenring ◽  
Sisi Liu ◽  
Weihan Jia ◽  
Kai Li ◽  
Luidmila Pestryakova ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Plant Diversity ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
The Arctic ◽  
Mean Annual Precipitation ◽  
Reference Database ◽  
Mean Annual Temperature ◽  
Diversity Assessment ◽  
Recent Climate

Plant diversity in the Arctic and at high altitudes strongly depends on and rebounds to climatic and environmental variability and is nowadays tremendously impacted by recent climate warming. Therefore, past changes in plant diversity in the high Arctic and high-altitude regions are used to infer climatic and environmental changes through time and allow future predictions. Sedimentary DNA (sedDNA) is an established proxy for the detection of local plant diversity in lake sediments, but still relationships between environmental conditions and preservation of the plant sedDNA proxy are far from being fully understood. Studying modern relationships between environmental conditions and plant sedDNA will improve our understanding under which conditions sedDNA is well-preserved helping to a.) evaluate suitable localities for sedDNA approaches, b.) provide analogues for preservation conditions and c.) conduct reconstruction of plant diversity and climate change. This study investigates modern plant diversity applying a plant-specific metabarcoding approach on sedimentary DNA of surface sediment samples from 262 lake localities covering a large geographical, climatic and ecological gradient. Latitude ranges between 25°N and 73°N and longitude between 81°E and 161°E, including lowland lakes and elevated lakes up to 5168 m a.s.l. Further, our sampling localities cover a climatic gradient ranging in mean annual temperature between -15°C and +18°C and in mean annual precipitation between 36­ and 935 mm. The localities in Siberia span over a large vegetational gradient including tundra, open woodland and boreal forest. Lake localities in China include alpine meadow, shrub, forest and steppe and also cultivated areas. The assessment of plant diversity in the underlying dataset was conducted by a specific plant metabarcoding approach. We provide a large dataset of genetic plant diversity retrieved from surface sedimentary DNA from lakes in Siberia and China spanning over a large environmental gradient. Our dataset encompasses sedDNA sequence data of 259 surface lake sediments and three soil samples originating from Siberian and Chinese lakes. We used the established chloroplastidal P6 loop trnL marker for plant diversity assessment. The merged, filtered and assigned dataset includes 15,692,944 read counts resulting in 623 unique plant DNA sequence types which have a 100% match to either the EMBL or to the specific Arctic plant reference database. The underlying dataset includes a taxonomic list of identified plants and results from PCR replicates, as well as extraction blanks (BLANKs) and PCR negative controls (NTCs), which were run along with the investigated lake samples. This collection of plant metabarcoding data from modern lake sediments is still ongoing and additional data will be released in the future.

Life history and environmental influences on population dynamics in sockeye salmon

2014 ◽  
Vol 71 (8) ◽  
pp. 1198-1208 ◽  
Author(s):  
Douglas C. Braun ◽  
John D. Reynolds
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Population Growth ◽  
Growth Rates ◽  
Environmental Conditions ◽  
Sockeye Salmon ◽  
Life History Traits ◽  
Relative Importance ◽  
Population Growth Rates ◽  
Habitat Variables

Understanding linkages among life history traits, the environment, and population dynamics is a central goal in ecology. We compared 15 populations of sockeye salmon (Oncorhynchus nerka) to test general hypotheses for the relative importance of life history traits and environmental conditions in explaining variation in population dynamics. We used life history traits and habitat variables as covariates in mixed-effect Ricker models to evaluate the support for correlates of maximum population growth rates, density dependence, and variability in dynamics among populations. We found dramatic differences in the dynamics of populations that spawn in a small geographical area. These differences among populations were related to variation in habitats but not life history traits. Populations that spawned in deep water had higher and less variable population growth rates, and populations inhabiting streams with larger gravels experienced stronger negative density dependence. These results demonstrate, in these populations, the relative importance of environmental conditions and life histories in explaining population dynamics, which is rarely possible for multiple populations of the same species. Furthermore, they suggest that local habitat variables are important for the assessment of population status, especially when multiple populations with different dynamics are managed as aggregates.

Ammonium Sulfate Increases Efficacy of Sethoxydim Through Increased Absorption and Translocation

Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 351-358 ◽  
Author(s):  
Anne M. Smith ◽  
William H. Vanden Born
Keyword(s):  
Ammonium Sulfate ◽  
Environmental Conditions ◽  
Dry Weight ◽  
Model Systems ◽  
Short Term ◽  
Wild Oats

The effect of ammonium sulfate (AMS) on efficacy and on absorption and translocation of sethoxydim in wild oats and barley was investigated under controlled environmental conditions. Increases in efficacy in the presence of AMS were relatively small. The rate of sethoxydim required to reduce dry weight 50% was reduced from 0.08 kg a.i. ha−1, for both species, to 0.07 and 0.06 kg ha−1for wild oats and barley, respectively, in the presence of added AMS. In short-term experiments, uptake of14C from14C-labeled sethoxydim 0.5 and 1 h after application was increased approximately twofold with the addition of AMS. AMS had little effect on sethoxydim absorption beyond 1 h after application. Translocation at 1 h after application was unaffected by AMS. However, translocation 12 and 24 h after application was increased with AMS. It is postulated that the translocation increase results indirectly from the increase in absorption. The observed increase in absorption with the addition of AMS is evident only when crop oil concentrate (COC) is also present In model systems, the addition of AMS enhanced sorption of sethoxydim into Isolated cuticles but had no effect on movement into excised roots.

scholarly journals A sensitivity analysis of price formulae

1985 ◽  
Vol 16 (4) ◽  
pp. 181-184
Author(s):  
J. J. Doppegieter ◽  
I. J. Lambrechts
Keyword(s):  
Inflation Rate ◽  
Rate Of Return ◽  
Model Parameters ◽  
Relative Importance ◽  
Internal Rate Of Return ◽  
Short Term ◽  
Tax Rate ◽  
Internal Rate ◽  
Price Formula ◽  
Statutory Tax Rate

This is the last in a series of four articles. In the first article two price formulae were discussed and in the subsequent two articles two methods of analysis were demonstrated. In this article a third method of analysis concerning the sensitivity of some selected model parameters is presented. Four parameters have been selected, i.e. the allowed profitability rate, the inflation rate, the growth rate, and the statutory tax rate. The value of each factor has been increased and decreased by 10% to test the sensitivity of each. In both price formulae the allowed profitability rate has the highest relative importance, followed by the inflation rate. Furthermore, in price formula A some parameters have no or only a small short-term effect on the internal rate of return, e.g. the statutory tax rate. In addition, the internal rate of return of formula A is generally more volatile to changes in the variables analysed than that of formula B. This type of analysis could be very helpful for negotiations between price/tariff-determining bodies and price-controlled undertakings/industries.

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