scholarly journals Memories of Migrations Past: Sociality and Cognition in Dynamic, Seasonal Environments

2021 ◽  
Vol 9 ◽  
Author(s):  
Eliezer Gurarie ◽  
Sriya Potluri ◽  
George Christopher Cosner ◽  
Robert Stephen Cantrell ◽  
William F. Fagan
Keyword(s):  
Environmental Changes ◽  
Animal Movement ◽  
Spatial Scales ◽  
Rapid Change ◽  
Reference Memory ◽  
Migratory Behavior ◽  
Migration Behavior ◽  
Long Distance ◽  
Trade Offs ◽  
Resource Dynamics

Seasonal migrations are a widespread and broadly successful strategy for animals to exploit periodic and localized resources over large spatial scales. It remains an open and largely case-specific question whether long-distance migrations are resilient to environmental disruptions. High levels of mobility suggest an ability to shift ranges that can confer resilience. On the other hand, a conservative, hard-wired commitment to a risky behavior can be costly if conditions change. Mechanisms that contribute to migration include identification and responsiveness to resources, sociality, and cognitive processes such as spatial memory and learning. Our goal was to explore the extent to which these factors interact not only to maintain a migratory behavior but also to provide resilience against environmental changes. We develop a diffusion-advection model of animal movement in which an endogenous migratory behavior is modified by recent experiences via a memory process, and animals have a social swarming-like behavior over a range of spatial scales. We found that this relatively simple framework was able to adapt to a stable, seasonal resource dynamic under a broad range of parameter values. Furthermore, the model was able to acquire an adaptive migration behavior with time. However, the resilience of the process depended on all the parameters under consideration, with many complex trade-offs. For example, the spatial scale of sociality needed to be large enough to capture changes in the resource, but not so large that the acquired collective information was overly diluted. A long-term reference memory was important for hedging against a highly stochastic process, but a higher weighting of more recent memory was needed for adapting to directional changes in resource phenology. Our model provides a general and versatile framework for exploring the interaction of memory, movement, social and resource dynamics, even as environmental conditions globally are undergoing rapid change.

scholarly journals Montane Temperate-Boreal Forests Retain the Leaf Economic Spectrum Despite Intraspecific Variability

2022 ◽  
Vol 4 ◽  
Author(s):  
Matthew J. Hecking ◽  
Jenna M. Zukswert ◽  
John E. Drake ◽  
Martin Dovciak ◽  
Julia I. Burton
Keyword(s):  
Tree Species ◽  
Environmental Changes ◽  
Plant Traits ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
Intraspecific Variability ◽  
Trade Offs ◽  
Species Trait ◽  
Leaf Economic Spectrum ◽  
Trait Variability

Trait-based analyses provide powerful tools for developing a generalizable, physiologically grounded understanding of how forest communities are responding to ongoing environmental changes. Key challenges lie in (1) selecting traits that best characterize the ecological performance of species in the community and (2) determining the degree and importance of intraspecific variability in those traits. Recent studies suggest that globally evident trait correlations (trait dimensions), such as the leaf economic spectrum, may be weak or absent at local scales. Moreover, trait-based analyses that utilize a mean value to represent a species may be misleading. Mean trait values are particularly problematic if species trait value rankings change along environmental gradients, resulting in species trait crossover. To assess how plant traits (1) covary at local spatial scales, (2) vary across the dominant environmental gradients, and (3) can be partitioned within and across taxa, we collected data on 9 traits for 13 tree species spanning the montane temperate—boreal forest ecotones of New York and northern New England. The primary dimension of the trait ordination was the leaf economic spectrum, with trait variability among species largely driven by differences between deciduous angiosperms and evergreen gymnosperms. A second dimension was related to variability in nitrogen to phosphorous levels and stem specific density. Levels of intraspecific trait variability differed considerably among traits, and was related to variation in light, climate, and tree developmental stage. However, trait rankings across species were generally conserved across these gradients and there was little evidence of species crossover. The persistence of the leaf economics spectrum in both temperate and high-elevation conifer forests suggests that ecological strategies of tree species are associated with trade-offs between resource acquisition and tolerance, and may be quantified with relatively few traits. Furthermore, the assumption that species may be represented with a single trait value may be warranted for some trait-based analyses provided traits were measured under similar light levels and climate conditions.

scholarly journals From tree to architecture: how functional morphology of arborescence connects plant biology, evolution and physics

2021 ◽  
Author(s):  
Anita Roth-Nebelsick ◽  
Tatiana Miranda ◽  
Martin Ebner ◽  
Wilfried Konrad ◽  
Christopher Traiser
Keyword(s):  
Land Plant ◽  
Plant Evolution ◽  
Ecological Niches ◽  
Long Distance ◽  
Ongoing Research ◽  
Long Distance Transport ◽  
Theoretical Approaches ◽  
Trade Offs ◽  
Interfacial Physics ◽  
Plant Water Transport

AbstractTrees are the fundamental element of forest ecosystems, made possible by their mechanical qualities and their highly sophisticated conductive tissues. The evolution of trees, and thereby the evolution of forests, were ecologically transformative and affected climate and biogeochemical cycles fundamentally. Trees also offer a substantial amount of ecological niches for other organisms, such as epiphytes, creating a vast amount of habitats. During land plant evolution, a variety of different tree constructions evolved and their constructional principles are a subject of ongoing research. Understanding the “natural construction” of trees benefits strongly from methods and approaches from physics and engineering. Plant water transport is a good example for the ongoing demand for interdisciplinary efforts to unravel form-function relationships on vastly differing scales. Identification of the unique mechanism of water long-distance transport requires a solid basis of interfacial physics and thermodynamics. Studying tree functions by using theoretical approaches is, however, not a one-sided affair: The complex interrelationships between traits, functionality, trade-offs and phylogeny inspire engineers, physicists and architects until today.

scholarly journals Temporal changes in reproductive success and optimal breeding decisions in a long-distance migratory bird

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Cynthia Reséndiz-Infante ◽  
Gilles Gauthier
Keyword(s):  
Reproductive Success ◽  
Clutch Size ◽  
Environmental Changes ◽  
Migratory Bird ◽  
Laying Date ◽  
Negative Consequences ◽  
Breeding Phenology ◽  
Additional Time ◽  
Long Distance ◽  
Seasonal Decline

AbstractMany avian migrants have not adjusted breeding phenology to climate warming resulting in negative consequences for their offspring. We studied seasonal changes in reproductive success of the greater snow goose (Anser caerulescens atlantica), a long-distance migrant. As the climate warms and plant phenology advances, the mismatch between the timing of gosling hatch and peak nutritive quality of plants will increase. We predicted that optimal laying date yielding highest reproductive success occurred earlier over time and that the seasonal decline in reproductive success increased. Over 25 years, reproductive success of early breeders increased by 42%, producing a steeper seasonal decline in reproductive success. The difference between the laying date producing highest reproductive success and the median laying date of the population increased, which suggests an increase in the selection pressure for that trait. Observed clutch size was lower than clutch size yielding the highest reproductive success for most laying dates. However, at the individual level, clutch size could still be optimal if the additional time required to acquire nutrients to lay extra eggs is compensated by a reduction in reproductive success due to a delayed laying date. Nonetheless, breeding phenology may not respond sufficiently to meet future environmental changes induced by warming temperatures.

scholarly journals Limited Access to Food and Physiological Trade‐Offs in a Long‐Distance Migrant Shorebird. I. Energy Metabolism, Behavior, and Body‐Mass Regulation

2009 ◽  
Vol 82 (5) ◽  
pp. 549-560 ◽  
Author(s):  
François Vézina ◽  
Magali Petit ◽  
Deborah M. Buehler ◽  
Anne Dekinga ◽  
Theunis Piersma
Keyword(s):  
Energy Metabolism ◽  
Body Mass ◽  
Long Distance ◽  
Limited Access ◽  
Body Mass Regulation ◽  
Trade Offs ◽  
Access To Food

scholarly journals Economic and ecological trade-offs of agricultural specialization at different spatial scales

2016 ◽  
Vol 122 ◽  
pp. 111-120 ◽  
Author(s):  
Stephan Klasen ◽  
Katrin M. Meyer ◽  
Claudia Dislich ◽  
Michael Euler ◽  
Heiko Faust ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Trade Offs

scholarly journals Limited Access to Food and Physiological Trade‐Offs in a Long‐Distance Migrant Shorebird. II. Constitutive Immune Function and the Acute‐Phase Response

2009 ◽  
Vol 82 (5) ◽  
pp. 561-571 ◽  
Author(s):  
Deborah M. Buehler ◽  
Francisco Encinas‐Viso ◽  
Magali Petit ◽  
François Vézina ◽  
B. Irene Tieleman ◽  
...  
Keyword(s):  
Immune Function ◽  
Acute Phase ◽  
Acute Phase Response ◽  
Phase Response ◽  
Long Distance ◽  
Limited Access ◽  
Trade Offs ◽  
Access To Food

A framework for the Integrated Assessment of SDG trade-offs in the Sundarbans Biosphere Reserve.

2021 ◽  
Author(s):  
Charlotte Marcinko ◽  
Robert Nicholls ◽  
Tim Daw ◽  
Sugata Hazra ◽  
Craig Hutton ◽  
...  
Keyword(s):  
Environmental Change ◽  
Integrated Assessment ◽  
Spatial Scales ◽  
Strong Dependence ◽  
Management Strategies ◽  
Rural Livelihoods ◽  
Biosphere Reserve ◽  
Integrated Analysis ◽  
Trade Offs ◽  
The Sundarbans

<p>The United Nations Sustainable Development Goals (SDGs) and their corresponding targets are significantly interconnected, with many interactions, synergies and trade-offs between individual goals across multiple temporal and spatial scales.  We propose a framework for the Integrated Assessment Modelling (IAM) of a complex deltaic socio-ecological system in order to analyse such SDG interactions. We focus on the Sundarbans Biosphere Reserve (SBR), India within the Ganges-Brahmaputra-Meghna Delta. It is densely populated with 4.4 million people (2011), high levels of poverty and a strong dependence on rural livelihoods. It is only 50 km from the growing megacity of Kolkata (about 15 million people in 2020). The area also includes the Indian portion of the world’s largest mangrove forest – the Sundarbans – hosting the iconic Bengal Tiger. Like all deltaic systems, this area is subject to multiple drivers of environmental change operating across different scales. The IAM framework is designed to investigate current and future trends in socio-environmental change and explore associated policy impacts, considering a broad range of sub-thematic SDG indicators. Integration is achieved through the soft coupling of multiple sub-models, knowledge and data of relevant environmental and socio-economic processes.  The following elements are explicitly considered: (1) agriculture; (2) aquaculture; (3) mangroves; (4) fisheries; and (5) multidimensional poverty. Key questions that can be addressed include the implications of changing monsoon patterns, trade-offs between agriculture and aquaculture, or the future of the Sundarbans mangroves under sea-level rise and different management strategies, including trade-offs with land use to the north.  The novel high-resolution analysis of SDG interactions allowed by the IAM will provide stakeholders and policy makers the opportunity to prioritize and explore the SDG targets that are most relevant to the SBR and provide a foundation for further integrated analysis.</p>

Functional diversity alters the effects of a pulse perturbation on the dynamics of tritrophic food webs

2021 ◽  
Author(s):  
Ruben Ceulemans ◽  
Laurie Anne Myriam Wojcik ◽  
Ursula Gaedke
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Functional Diversity ◽  
Feedback Loop ◽  
Environmental Changes ◽  
Biodiversity Loss ◽  
Trophic Levels ◽  
Nutrient Pulse ◽  
Trade Offs ◽  
Food Web Model

Biodiversity decline causes a loss of functional diversity, which threatens ecosystems through a dangerous feedback loop: this loss may hamper ecosystems' ability to buffer environmental changes, leading to further biodiversity losses. In this context, the increasing frequency of climate and human-induced excessive loading of nutrients causes major problems in aquatic systems. Previous studies investigating how functional diversity influences the response of food webs to disturbances have mainly considered systems with at most two functionally diverse trophic levels. Here, we investigate the effects of a nutrient pulse on the resistance, resilience and elasticity of a tritrophic---and thus more realistic---plankton food web model depending on its functional diversity. We compare a non-adaptive food chain with no diversity to a highly diverse food web with three adaptive trophic levels. The species fitness differences are balanced through trade-offs between defense/growth rate for prey and selectivity/half-saturation constant for predators. We showed that the resistance, resilience and elasticity of tritrophic food webs decreased with larger perturbation sizes and depended on the state of the system when the perturbation occured. Importantly, we found that a more diverse food web was generally more resistant, resilient, and elastic. Particularly, functional diversity dampened the probability of a regime shift towards a non-desirable alternative state. In addition, despite the complex influence of the shape and type of the dynamical attractors, the basal-intermediate interaction determined the robustness against a nutrient pulse. This relationship was strongly influenced by the diversity present and the third trophic level. Overall, using a food web model of realistic complexity, this study confirms the destructive potential of the positive feedback loop between biodiversity loss and robustness, by uncovering mechanisms leading to a decrease in resistance, resilience and elasticity as functional diversity declines.

scholarly journals A multiscale approach to balance trade-offs among dam infrastructure, river restoration, and cost

2018 ◽  
Vol 115 (47) ◽  
pp. 12069-12074 ◽  
Author(s):  
Samuel G. Roy ◽  
Emi Uchida ◽  
Simone P. de Souza ◽  
Ben Blachly ◽  
Emma Fox ◽  
...  
Keyword(s):  
New England ◽  
River Restoration ◽  
Spatial Scales ◽  
Dam Removal ◽  
The United States ◽  
Multiscale Approach ◽  
Funding Policy ◽  
Net Benefit ◽  
Trade Offs ◽  
Aging Infrastructure

Aging infrastructure and growing interests in river restoration have led to a substantial rise in dam removals in the United States. However, the decision to remove a dam involves many complex trade-offs. The benefits of dam removal for hazard reduction and ecological restoration are potentially offset by the loss of hydroelectricity production, water supply, and other important services. We use a multiobjective approach to examine a wide array of trade-offs and synergies involved with strategic dam removal at three spatial scales in New England. We find that increasing the scale of decision-making improves the efficiency of trade-offs among ecosystem services, river safety, and economic costs resulting from dam removal, but this may lead to heterogeneous and less equitable local-scale outcomes. Our model may help facilitate multilateral funding, policy, and stakeholder agreements by analyzing the trade-offs of coordinated dam decisions, including net benefit alternatives to dam removal, at scales that satisfy these agreements.

scholarly journals Use of Citizen Science Data for Characterizing Patterns and Drivers of Avian Altitudinal Migration

2019 ◽  
Vol 3 ◽  
Author(s):  
Pei-Yu Tsai ◽  
Chie-Jen Ko ◽  
Ya-Jung Lu ◽  
Chia Hsieh ◽  
Mao-Ning Tuanmu
Keyword(s):  
Citizen Science ◽  
Environmental Changes ◽  
Global Analysis ◽  
Research Question ◽  
Bird Species ◽  
Migration Behavior ◽  
Mountain Regions ◽  
Science Data ◽  
Essential Information ◽  
Altitudinal Migration

Altitudinal migration, the seasonal and repeateing movement of animal individuals between breeding and non-breeding areas at different elevations, is a common and important but understudied behavior in birds. Difficulty in characterizing avian altitudinal migration has prevented a comprehensive understanding of both patterns and drivers of this behavior. To fill this knowledge gap, we investigated altitudinal migration patterns and underlying mechanisms for a major proportion (~70%) of an entire resident bird community on a subtropical island with an almost 4000-m elevational gradient. We quantified migration tendency of individual bird species based on the seasonal shift in the elevational distribution of their occurrence records in the eBird database. We then built phylogeny-controlled regression models to examine the associations between the birds’ migration tendencies and their functional traits to test major hypotheses on the mechanisms of altitudinal migration. The results showed a common but variable altitudinal migration behavior among the 118 species examined, with 40 and 11 species conducting post-breeding downhill and uphill migration, respectively. The species that have a narrower thermal tolerance range, can tolerate lower temperatures, have a smaller body size, have a more diverse or invertebrate-rich diet, or use an open nest had a higher downhill migration tendency. In contrast, no traits examined showed consistent associations with the uphill migration tendency. This suggests that post-breeding downhill and uphill migrations are driven by different processes and current hypotheses can only explain the former, but not the latter. This relatively comprehensive study demonstrated the power of citizen science data to provide new insights into an old research question from a novel perspective. Using the same approach, we are investigating the behavior in mountain regions around the world. With the global analysis, we will be able to understand the general patterns and mechanisms of avian altitudinal migration and also investigate their variation among mountain regions in different climate zones. In the face of rapid environmental changes in mountain ecosystems, the approach used in this study may also provide essential information for the conservation of mountainous biodiversity.

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