scholarly journals Life on the edge: diet preferences reflect adaptation to drought in Neotoma fuscipes

2016 ◽  
Author(s):  
Brendan J Barrett ◽  
Arielle Crews ◽  
Mary Brooke McElreath
Keyword(s):  
Environmental Changes ◽  
Behavioral Flexibility ◽  
Food Preferences ◽  
Ecological Change ◽  
Generalist Herbivores ◽  
Edge Habitat ◽  
Neotoma Fuscipes ◽  
Dietary Flexibility ◽  
Drought Tolerant ◽  
Diet Preferences

ABSTRACTEcological change due to habitat fragmentation and climate change can decrease population viability, especially in herbivores and the plant communities upon which they depend. Behavioral flexibility is one important adaptation to both patchy or edge habitats undergoing rapid environmental change. This is true in many generalist herbivores, whose diet preferences can vary substantially, both geographically and over time. Little is known about what plants allow generalist herbivores to respond to rapid environmental changes, and whether these responses are due to variability in diet preference in a population, or individual dietary flexibility. We investigated how the diet preferences of dusky-footed woodrats (Neotoma fuscipes) might allow them to respond to drought in a spatially heterogeneous environment. We conducted cafeteria trials on woodrats during a year of extreme drought to assess individual preferences for locally available plants compared to more drought-tolerant edge vegetation. Our results show that woodrats sample a number of plants, but tend to prefer scrub oak, a dominant plant species in the available habitat, as well as chamise- a highly drought-tolerant plant predominantly present in the surrounding edge habitat. No difference in food preferences was detected between sexes, but we found evidence for an effect based on age and proximity to edge habitat. Juveniles who lived closer to the habitat edge were more likely to consume, and consumed greater amounts of plants in cafeteria trials compared to adults and juveniles living further from the edge. In addition to oak and chamise, adults sampled large quantities of other plants such as poison oak and California buckeye, and in general included a wider array of plants in their preferred diets compared to juveniles. We conclude with a discussion of the management implications and outlook for woodrats in the Coast Range of northern California.

A simple method to assess macrofungal sporocarp biomass for investigating ecological change

2007 ◽  
Vol 85 (7) ◽  
pp. 652-658 ◽  
Author(s):  
B.B. Tóth ◽  
A. Feest
Keyword(s):  
Environmental Changes ◽  
Fine Root ◽  
Dry Mass ◽  
Accurate Estimation ◽  
Ecological Change ◽  
Fruiting Bodies ◽  
Ectomycorrhizal Community ◽  
Simple Method ◽  
Area Index ◽  
Forested Areas

The methodologies used for studying macrofungal communities are an eclectic assemblage of many different and unstandardized approaches. In this study we propose a simple, nondestructive but still informative method to assess fungal sporocarp biomass in forested areas. We use the number of fruiting bodies found in the surveyed plot, and data on cap diameter of the species from the literature to calculate a cap area index. We show that this index very strongly correlates with the measured total dry mass of the species obtained from the same plot. We point out that the cap area index provides a more accurate estimation of the epigeous fungal sporocarp biomass than do the species sporocarp numbers. This new methodology allows the spatiotemporal distribution of a fungal community in an ecosystem to be followed. Since sporocarp production responds much more sensitively to environmental changes than does the fine-root vegetative ectomycorrhizal community, it may more quickly reflect whether an ecosystem has been perturbed. It will also allow us to collect data on saprotrophic species. A sporocarp survey can be useful for detecting early changes in the habitat and environment, and give an easily applicable method for conservation biology and ecosystem management.

scholarly journals A picture of change: using photovoice to explore social and environmental change in coastal communities on the Andaman Coast of Thailand

2018 ◽  
Author(s):  
Nathan Bennett ◽  
Philip Dearden
Keyword(s):  
Environmental Change ◽  
Environmental Changes ◽  
Coastal Communities ◽  
Ecological Change ◽  
Social Changes ◽  
Scientific Methods ◽  
Social Trends ◽  
Macro Scale ◽  
Social And Environmental Change ◽  
Social Environmental

Coastal communities experience a wide array of environmental and social changes to which they must constantly adapt. Further, a community's perception of change and risk has significant implications for a community's willingness and ability to adapt to both current and future changes. As part of a larger study focusing on the adaptive capacity of communities on the Andaman Coast of Thailand, we used Photovoice to open a dialogue with communities about changes in the marine environment and in coastal communities. This article presents the results of two exploratory Photovoice processes and discusses prospects for using the Photovoice method for exploring social and environmental change. Changes examined included a number of broader environmental and social trends as well as ecological specifics and social particularities in each site. Participants also explored the social implications of environmental changes, the impacts of macro-scale processes on local outcomes, and emotive and active responses of individuals and communities to change. Photovoice is deemed a powerful method for: examining social, environmental, and socio-ecological change, triangulating to confirm the results of other scientific methods, revealing novel ecological interactions, and providing input into community processes focusing on natural resource management, community development, and climate change adaptation.

scholarly journals Water deficit in the soybean breeding

2021 ◽  
Vol 7 ◽  
pp. 1-20
Author(s):  
João Roberto Pimentel ◽  
Ivan Ricardo Carvalho ◽  
Cristian Troyjack ◽  
Gilberto Troyjack Junior ◽  
Vinicius Jardel Szareski ◽  
...  
Keyword(s):  
Abiotic Stresses ◽  
Genetic Improvement ◽  
Environmental Changes ◽  
Complex Phenomenon ◽  
Main Risk Factor ◽  
Drought Tolerant ◽  
Technological Advances ◽  
Wide Range ◽  
Growth Constraints ◽  
Sessile Organisms

The climate unpredictability causes long periods of drought, becoming the main risk factor in soybeans production fields and consequent losses to farmers in Brazil and worldwide. As sessile organisms, plants are constantly challenged by a wide range of environmental stresses, including drought. Growth constraints and stress due to these environmental changes result in reduced yield and significant harvesting losses. The response to abiotic stresses is a very complex phenomenon, since several stages of plant development can be affected by a particular stress and often several stresses affect the plant simultaneously. In order to mitigate the damages caused by the climate, new soybean cultivars adapted to the drought and the diversified climate are necessary, as well as technological advances in the production of soybeans that must advance with the increase of cultivated area. Therefore, the mechanisms underlying tolerance and adaptation to stress have been the focus of intensive research. In this sense, the objective of this review is to provide an overview of the evolution of genetic improvement regarding the search for more drought-tolerant cultivars, as well as to verify which strategies are used in the genetic improvement of soybean in the search of these genotypes.

Late Pleistocene environments of the Bighorn Basin, Wyoming-Montana, USA

2020 ◽  
pp. 1-14
Author(s):  
Thomas A. Minckley ◽  
Mark Clementz ◽  
Marcel Kornfeld ◽  
Mary Lou Larson ◽  
Judson B. Finley
Keyword(s):  
Late Pleistocene ◽  
Environmental Changes ◽  
Isotope Analysis ◽  
Younger Dryas ◽  
Ecological Change ◽  
Bighorn Basin ◽  
Bulk Organic Matter ◽  
Intermontane Basins ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract Limited numbers of high-resolution records predate the Last Glacial Maximum (LGM) making it difficult to quantify the impacts of environmental changes prior to peak glaciation. We examined sediments from Last Canyon Cave in the Pryor Mountains of Montana and Wyoming to construct a >45 ka environmental record from pollen and stable isotope analysis. Artemisia pollen was hyper-abundant at the beginning of the record. Carbon isotope values of bulk organic matter (>40 ka) showed little variation (-25.3 ± 0.4‰) and were consistent with a arid C3 environment, similar to today. After 40 cal ka BP, Artemisia pollen decreased as herbaceous taxa increased toward the LGM. A significant decrease in δ13C values from 40–30 cal ka BP (~1.0‰) established a new baseline (-26.6 ± 0.2‰), suggesting cooler, seasonally wetter conditions prior to the LGM. These conditions persisted until variation in δ13C values increased significantly with post-glacial warming, marked by two spikes in values at 14.4 (-25.2‰) and 13.5 cal ka BP (-25.4‰) before δ13C values dropped to their lowest values (-26.9 ± 0.2‰) at the onset of the Younger Dryas (12.8 ka). These results provide insights into late Pleistocene conditions and ecological change in arid intermontane basins of the Rocky Mountains.

scholarly journals Similar foraging energetics of two sympatric albatrosses despite contrasting life histories and wind-mediated foraging strategies

2020 ◽  
Vol 223 (23) ◽  
pp. jeb228585 ◽  
Author(s):  
Caitlin E. Kroeger ◽  
Daniel E. Crocker ◽  
Rachael A. Orben ◽  
David R. Thompson ◽  
Leigh G. Torres ◽  
...  
Keyword(s):  
Energy Balance ◽  
Life Histories ◽  
Behavioral Plasticity ◽  
Environmental Changes ◽  
Behavioral Flexibility ◽  
Mass Gain ◽  
Central Place ◽  
Foraging Strategies ◽  
Wind Speeds ◽  
Ocean Environment

ABSTRACTUnderstanding the environmental and behavioral factors that influence how organisms maintain energy balance can inform us about their potential resiliency to rapid environmental changes. Flexibility in maintaining energy balance is particularly important to long-lived, central-place foraging seabirds that are constrained when locating food for offspring in a dynamic ocean environment. To understand the role of environmental interactions, behavioral flexibility and morphological constraints on energy balance, we used doubly labeled water to measure the at-sea daily energy expenditure (DEE) of two sympatrically breeding seabirds, Campbell (Thalassarche impavida) and grey-headed (Thalassarchechrysostoma) albatrosses. We found that species and sexes had similar foraging costs, but DEE varied between years for both species and sexes during early chick rearing in two consecutive seasons. For both species, greater DEE was positively associated with larger proportional mass gain, lower mean wind speeds during water take-offs, greater proportions of strong tailwinds (>12 m s−1), and younger chick age. Greater proportional mass gains were marginally more costly in male albatrosses that already have higher wing loading. DEE was higher during flights with a greater proportion of strong headwinds for grey-headed albatrosses only. Poleward winds are forecasted to intensify over the next century, which may increase DEE for grey-headed albatrosses that heavily use this region during early chick rearing. Female Campbell albatrosses may be negatively affected by forecasted slackening winds at lower latitudes due to an expected greater reliance on less energy efficient sit-and-wait foraging strategies. Behavioral plasticity associated with environmental variation may influence future population responses to climate change of both species.

scholarly journals Allelic Variation in Taste Genes Is Associated with Taste and Diet Preferences and Dental Caries

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1491 ◽  
Author(s):  
Linda Eriksson ◽  
Anders Esberg ◽  
Simon Haworth ◽  
Pernilla Lif Holgerson ◽  
Ingegerd Johansson
Keyword(s):  
Food Intake ◽  
Food Preference ◽  
Glucose Transporter ◽  
Allelic Variation ◽  
Food Selection ◽  
Taste Receptor ◽  
Food Preferences ◽  
Sweet Taste ◽  
Taste Perception ◽  
Diet Preferences

Taste and diet preferences are complex and influenced by both environmental and host traits while affecting both food selection and associated health outcomes. The present study genotyped 94 single nucleotide polymorphisms (SNPs) in previously reported taste and food intake related genes and assessed associations with taste threshold (TT) and preferred intensity (PT) of sweet, sour and bitter, food preferences, habitual diet intake, and caries status in healthy young Swedish men and women (n = 127). Polymorphisms in the GNAT3, SLC2A4, TAS1R1 and TAS1R2 genes were associated with variation in TT and PT for sweet taste as well as sweet food intake. Increasing PT for sweet was associated with increasing preference and intake of sugary foods. Similarly, increasing TT for sour was associated with increasing intake of sour foods, whereas the associations between food preference/intake and TT/PT for bitter was weak in this study group. Finally, allelic variation in the GNAT3, SLC2A2, SLC2A4, TAS1R1 and TAS1R2 genes was associated with caries status, whereas TT, PT and food preferences were not. It was concluded that variations in taste receptor, glucose transporter and gustducin encoding genes are related to taste perception, food preference and intake as well as the sugar-dependent caries disease.

Using zooplankton biomass size spectra to assess ecological change in a well-studied freshwater lake ecosystem: Oneida Lake, New York

2006 ◽  
Vol 63 (12) ◽  
pp. 2687-2699 ◽  
Author(s):  
Allison E Gamble ◽  
Russ Lloyd ◽  
John Aiken ◽  
Ora E Johannsson ◽  
Edward L Mills
Keyword(s):  
New York ◽  
Linear Model ◽  
Environmental Changes ◽  
General Linear Model ◽  
Zooplankton Biomass ◽  
Freshwater Lake ◽  
General Linear ◽  
Ecological Change ◽  
Size Spectra ◽  
Oneida Lake

We explored the sensitivity of three descriptors of zooplankton size spectra (slope, periodic, and Pareto II models) to environmental changes in Oneida Lake, New York, and then used documented environmental changes to model the responses of zooplankton biomass using a general linear model. Using multiple regressions, we identified significant ecological events in Oneida Lake that could affect zooplankton biomass before actual model testing and assessed the three size spectrum models based on their sensitivity to these known variables. The intercept of the slope (linear regression) model was responsive to changes, but the slope was not. The periodic (quadratic) model showed no sensitivity in detecting ecological change. The Pareto II model (probability distribution function) demonstrated the most sensitivity to all ecological variables but was complex to model and there was no direct relationship between its parameters and biological events. The general linear model regression approach proved relatively sensitive to environmental change and had the added benefit of providing a graphical means of biologically assessing differences between years. In general, zooplankton biomass size spectra were responsive to changes in conditions in the Oneida Lake environment, and we believe that size-based approaches have potential as a biotic index in freshwater lake ecosystems.

scholarly journals Cultural selection and human food preferences

2019 ◽  
Vol 92 (1) ◽  
Author(s):  
Ani Bajrami
Keyword(s):  
Energy Storage ◽  
Positive Selection ◽  
Genetic Drift ◽  
Dietary Habits ◽  
Environmental Changes ◽  
Food Preferences ◽  
Overweight And Obesity ◽  
High Rate ◽  
Cultural Selection ◽  
Selection For

Genes and culture co-evolve to determine variations in dietary habits. Our evolutionary heritage regarding food choice and food preferences is responsible for the mismatch with the food environments we have created, which leads to problems such as overweight and obesity. Several hypotheses have attempted to explain the high rate of obesity present in today’s world. The thrifty genotype hypothesis suggested that obesity today is a throwback to our ancestors having undergone positive selection for genes that favored energy storage. The drifty genotype hypothesis contends that the prevalence of thrifty genes is not a result of positive selection for energy-storage genes but, rather, is attributable to genetic drift resulting from the removal of predatory selection pressures. Both hypotheses focus on environmental changes over time, positive selection and genetic drift. While genetics plays a significant role, we believe that cultural selection is also responsible for the spread of obesogenic phenomena in Albania. The high rates of overweight and obesity among Albanians today can be explained as a mismatch between our evolutionary past and maladaptive behaviors.

scholarly journals Individual Variation in Dietary Wariness Is Predicted by Head Color in a Specialist Feeder, the Gouldian Finch

2021 ◽  
Vol 9 ◽  
Author(s):  
Georgina R. Eccles ◽  
Emily J. Bethell ◽  
Alison L. Greggor ◽  
Claudia Mettke-Hofmann
Keyword(s):  
Environmental Changes ◽  
Ecological Change ◽  
Generalist Species ◽  
Novel Food ◽  
Individual Level ◽  
Adaptive Combination ◽  
Dietary Breadth ◽  
The Social ◽  
Gouldian Finch ◽  
The Individual

Shifts in resource availability due to environmental change are increasingly confronting animals with unfamiliar food types. Species that can rapidly accept new food types may be better adapted to ecological change. Intuitively, dietary generalists are expected to accept new food types when resources change, while dietary specialists would be more averse to adopting novel food. However, most studies investigating changes in dietary breadth focus on generalist species and do not delve into potential individual predictors of dietary wariness and the social factors modulating these responses. We investigated dietary wariness in the Gouldian finch, a dietary specialist, that is expected to avoid novel food. This species occurs in two main head colors (red, black), which signal personality in other contexts. We measured their initial neophobic responses (approach attempts before first feed and latency to first feed) and willingness to incorporate novel food into their diet (frequency of feeding on novel food after first feed). Birds were tested in same-sex pairs in same and different head color pairings balanced across experiments 1 and 2. Familiar and novel food (familiar food dyed) were presented simultaneously across 5 days for 3 h, each. Gouldian finches fed on the familiar food first demonstrating food neophobia, and these latencies were repeatable. Birds made more approach attempts before feeding on novel than familiar food, particularly red-headed birds in experiment 1 and when partnered with a black-headed bird. Individuals consistently differed in their rate of incorporation of novel food, with clear differences between head colors; red-headed birds increased their feeding visits to novel food across experimentation equaling their familiar food intake by day five, while black-headed birds continually favored familiar food. Results suggest consistent among individual differences in response to novel food with red-headed birds being adventurous consumers and black-headed birds dietary conservatives. The differences in food acceptance aligned with responses to novel environments on the individual level (found in an earlier study) providing individuals with an adaptive combination of novelty responses across contexts in line with potential differences in movement patterns. Taken together, these novelty responses could aid in population persistence when faced with environmental changes.

Animal origins and the Tonian Earth system

2018 ◽  
Vol 2 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Daniel B. Mills ◽  
Warren R. Francis ◽  
Donald E. Canfield
Keyword(s):  
Cellular Differentiation ◽  
Environmental Changes ◽  
Three Dimensional ◽  
Global Ocean ◽  
Ecological Change ◽  
Earth System ◽  
Developmental Constraints ◽  
Low Latitude ◽  
Ecological Changes ◽  
Neoproterozoic Era

The Neoproterozoic Era (1000–541 million years ago, Ma) was characterized by dramatic environmental and evolutionary change, including at least two episodes of extensive, low-latitude glaciation, potential changes in the redox structure of the global ocean, and the origin and diversification of animal life. How these different events related to one another remains an active area of research, particularly how these environmental changes influenced, and were influenced by, the earliest evolution of animals. Animal multicellularity is estimated to have evolved in the Tonian Period (1000–720 Ma) and represents one of at least six independent acquisitions of complex multicellularity, characterized by cellular differentiation, three-dimensional body plans, and active nutrient transport. Compared with the other instances of complex multicellularity, animals represent the only clade to have evolved from wall-less, phagotrophic flagellates, which likely placed unique cytological and trophic constraints on the evolution of animal multicellularity. Here, we compare recent molecular clock estimates with compilations of the chromium isotope, micropaleontological, and organic biomarker records, suggesting that, as of now, the origin of animals was not obviously correlated to any environmental–ecological change in the Tonian Period. This lack of correlation is consistent with the idea that the evolution of animal multicellularity was primarily dictated by internal, developmental constraints and occurred independently of the known environmental–ecological changes that characterized the Neoproterozoic Era.

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