scholarly journals Can Top-Down Controls Expand the Ecological Niche of Marine N2 Fixers?

2021 ◽  
Vol 12 ◽  
Author(s):  
Angela Landolfi ◽  
A. E. Friederike Prowe ◽  
Markus Pahlow ◽  
Christopher J. Somes ◽  
Chia-Te Chien ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Ecological Niches ◽  
Ecological Interactions ◽  
Top Down ◽  
Viral Lysis ◽  
Controlled Systems ◽  
Trade Offs ◽  
Limiting Nutrient ◽  
Resource Levels ◽  
Critical Process

The ability of marine diazotrophs to fix dinitrogen gas (N2) is one of the most influential yet enigmatic processes in the ocean. With their activity diazotrophs support biological production by fixing about 100–200 Tg N/year and turning otherwise unavailable dinitrogen into bioavailable nitrogen (N), an essential limiting nutrient. Despite their important role, the factors that control the distribution of diazotrophs and their ability to fix N2 are not fully elucidated. We discuss insights that can be gained from the emerging picture of a wide geographical distribution of marine diazotrophs and provide a critical assessment of environmental (bottom-up) versus trophic (top-down) controls. We expand a simplified theoretical framework to understand how top-down control affects competition for resources that determine ecological niches. Selective mortality, mediated by grazing or viral-lysis, on non-fixing phytoplankton is identified as a critical process that can broaden the ability of diazotrophs to compete for resources in top-down controlled systems and explain an expanded ecological niche for diazotrophs. Our simplified analysis predicts a larger importance of top-down control on competition patterns as resource levels increase. As grazing controls the faster growing phytoplankton, coexistence of the slower growing diazotrophs can be established. However, these predictions require corroboration by experimental and field data, together with the identification of specific traits of organisms and associated trade-offs related to selective top-down control. Elucidation of these factors could greatly improve our predictive capability for patterns and rates of marine N2 fixation. The susceptibility of this key biogeochemical process to future changes may not only be determined by changes in environmental conditions but also via changes in the ecological interactions.

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 Microbiomes attached to fresh perennial ryegrass are temporally resilient and adapt to changing ecological niches

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sharon A. Huws ◽  
Joan E. Edwards ◽  
Wanchang Lin ◽  
Francesco Rubino ◽  
Mark Alston ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Perennial Ryegrass ◽  
Transcriptional Activity ◽  
Ecological Niches ◽  
Ecological Interactions ◽  
Carbohydrate Degradation ◽  
Host Nutrition ◽  
Role Based ◽  
Insight Into

Abstract Background Gut microbiomes, such as the rumen, greatly influence host nutrition due to their feed energy-harvesting capacity. We investigated temporal ecological interactions facilitating energy harvesting at the fresh perennial ryegrass (PRG)-biofilm interface in the rumen using an in sacco approach and prokaryotic metatranscriptomic profiling. Results Network analysis identified two distinct sub-microbiomes primarily representing primary (≤ 4 h) and secondary (≥ 4 h) colonisation phases and the most transcriptionally active bacterial families (i.e Fibrobacteriaceae, Selemondaceae and Methanobacteriaceae) did not interact with either sub-microbiome, indicating non-cooperative behaviour. Conversely, Prevotellaceae had most transcriptional activity within the primary sub-microbiome (focussed on protein metabolism) and Lachnospiraceae within the secondary sub-microbiome (focussed on carbohydrate degradation). Putative keystone taxa, with low transcriptional activity, were identified within both sub-microbiomes, highlighting the important synergistic role of minor bacterial families; however, we hypothesise that they may be ‘cheating’ in order to capitalise on the energy-harvesting capacity of other microbes. In terms of chemical cues underlying transition from primary to secondary colonisation phases, we suggest that AI-2-based quorum sensing plays a role, based on LuxS gene expression data, coupled with changes in PRG chemistry. Conclusions In summary, we show that fresh PRG-attached prokaryotes are resilient and adapt quickly to changing niches. This study provides the first major insight into the complex temporal ecological interactions occurring at the plant-biofilm interface within the rumen. The study also provides valuable insights into potential plant breeding strategies for development of the utopian plant, allowing optimal sustainable production of ruminants.

scholarly journals Defining the niche for niche construction: evolutionary and ecological niches

2021 ◽  
Vol 36 (3) ◽  
Author(s):  
Rose Trappes
Keyword(s):  
Evolutionary Biology ◽  
Ecological Niche ◽  
Niche Construction ◽  
Habitat Degradation ◽  
Ecological Niches ◽  
Niche Concept ◽  
Definition Of ◽  
Compare And Contrast ◽  
Extreme Habitat

AbstractNiche construction theory (NCT) aims to transform and unite evolutionary biology and ecology. Much of the debate about NCT has focused on construction. Less attention has been accorded to the niche: what is it, exactly, that organisms are constructing? In this paper I compare and contrast the definition of the niche used in NCT with ecological niche definitions. NCT’s concept of the evolutionary niche is defined as the sum of selection pressures affecting a population. So defined, the evolutionary niche is narrower than the ecological niche. Moreover, when contrasted with a more restricted ecological niche concept, it has a slightly different extension. I point out three kinds of cases in which the evolutionary niche does not coincide with realized ecological niches: extreme habitat degradation, commensalism, and non-limiting or super-abundant resources. These conceptual differences affect the role of NCT in unifying ecology and evolutionary biology.

scholarly journals An ecological niche shift for Neanderthal populations in Western Europe 70,000 years ago

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
William E. Banks ◽  
Marie-Hélène Moncel ◽  
Jean-Paul Raynal ◽  
Marlon E. Cobos ◽  
Daniel Romero-Alvarez ◽  
...  
Keyword(s):  
Material Culture ◽  
Ecological Niche ◽  
Western Europe ◽  
Ecological Niche Modeling ◽  
Climatic Variability ◽  
Niche Shift ◽  
Ecological Niches ◽  
Middle Paleolithic ◽  
Niche Dynamics ◽  
Anatomically Modern Humans

AbstractMiddle Paleolithic Neanderthal populations occupied Eurasia for at least 250,000 years prior to the arrival of anatomically modern humans. While a considerable body of archaeological research has focused on Neanderthal material culture and subsistence strategies, little attention has been paid to the relationship between regionally specific cultural trajectories and their associated existing fundamental ecological niches, nor to how the latter varied across periods of climatic variability. We examine the Middle Paleolithic archaeological record of a naturally constrained region of Western Europe between 82,000 and 60,000 years ago using ecological niche modeling methods. Evaluations of ecological niche estimations, in both geographic and environmental dimensions, indicate that 70,000 years ago the range of suitable habitats exploited by these Neanderthal populations contracted and shifted. These ecological niche dynamics are the result of groups continuing to occupy habitual territories that were characterized by new environmental conditions during Marine Isotope Stage 4. The development of original cultural adaptations permitted this territorial stability.

Distribution Patterns and Ecological Niches of the Red-tongued Pit Viper (Gloydius ussuriensis) and the Central Asian Pit Viper (Gloydius intermedius) in Cheonmasan Mountain, South Korea

2021 ◽  
Vol 28 (6) ◽  
pp. 348-354
Author(s):  
Min Seock Do ◽  
Ki-Baek Nam
Keyword(s):  
South Korea ◽  
Ecological Niche ◽  
Distribution Patterns ◽  
Niche Differentiation ◽  
Habitat Characteristics ◽  
Ecological Niches ◽  
Mountainous Area ◽  
Dry Land ◽  
Central Asian ◽  
Geographical Environment

Studies on the distribution of species are important to understanding the interspecific ecological niche and habitat selection through geographic environmental information. Particularly, vipers in the same genus have been an important topic because they show differences in the preferred geographical environment, depending on the distance of the phylogenetic relationship. This study investigated the geographical environment of red-tongued pit vipers (Gloydius ussuriensis) and Central Asian pit vipers (Gloydius intermedius) in the mountainous area, Cheonmasan Mountain County Park, South Korea, from April 2012 to October 2014, to understand the relationships among their habitat characteristics and ecological niche. Red-tongued pit vipers mainly lived in low altitude, wet valley areas with a low solar reflectance, while Central Asian pit vipers inhabited high altitude, dry land with large amounts of sunshine. As a result, our study supports that the ecological niche of red-tongued pit vipers and Central Asian pit vipers, inhibiting in Cheonmasan Mountain was overlapped low according to the majority of geographical environmental variables. The differentiated diet preference might be took into consideration as one of the potential key factors to the ecological niche differentiation among two species.

Introduction

2011 ◽  
Author(s):  
A. Townsend Peterson ◽  
Jorge Soberón ◽  
Richard G. Pearson ◽  
Robert P. Anderson ◽  
Enrique Martínez-Meyer ◽  
...  
Keyword(s):  
Conceptual Framework ◽  
Species Distribution ◽  
Ecological Niche ◽  
Ecological Niche Modeling ◽  
Species Distribution Modeling ◽  
Niche Modeling ◽  
Ecological Niches ◽  
Distribution Modeling ◽  
Geographic Distributions ◽  
Complex Relationships

This book deals with ecological niche modeling and species distribution modeling, two emerging fields that address the ecological, geographic, and evolutionary dimensions of geographic distributions of species. It provides a conceptual overview of the complex relationships between ecological niches and geographic distributions of species, both across space and (perhaps to a lesser degree) through time. The emphasis is on how that conceptual framework relates to ecological niche modeling and species distribution modeling, which the book argues are complementary and are most broadly applicable to diverse questions regarding the ecology and geography of biodiversity phenomena. Part I of the book introduces the conceptual framework for thinking about and discussing the distributional ecology of species, Part II is concerned with the data and tools that have been used in the early development of the field, and Part III focuses on real-world situations to which these tools have been applied.

The Biography of the Earth

2021 ◽  
pp. 200-213
Author(s):  
Elisabeth Ervin-Blankenheim
Keyword(s):  
Small Mammals ◽  
Ecological Niche ◽  
Late Jurassic ◽  
Big Bang ◽  
Ecological Niches ◽  
Asteroid Impact ◽  
The Earth ◽  
The One ◽  
Extinction Events ◽  
The Universe

The story of the Phanerozoic Eon continues in this chapter with the Mesozoic Era. The first period in the Mesozoic, the Triassic, was bookended by two extinction events, the one at the beginning, discussed in the prior chapter at the end of the Permian Period, the Great Dying, and then another at the end of the period, related to the further breakup of Pangea. Dinosaurs evolved and diversified during the Mesozoic to occupy nearly each and every ecological niche on the planet, with large dinosaurs and small dinosaurs, ones that flew, those that ate vegetation, and those that preyed upon the herbivores—making this time a dino-dominated age. In the late Jurassic Period, small mammals, many of them insectivores, were starting to become prevalent. The era ended with a “big bang” of a different type than is theorized as the start of the universe—with the Chicxulub asteroid impact 66 million years ago that ended the lives of most of the dinosaurs, the non-avian lines, and opened up new ecological niches for the next “masters of the universe,” the mammals.

Biology of pathogenic microorganisms

2020 ◽  
pp. 651-656
Author(s):  
Duncan J. Maskell ◽  
James L.N. Wood
Keyword(s):  
Gene Expression ◽  
Ecological Niche ◽  
Rich Source ◽  
Ecological Niches ◽  
Pathogenic Microorganisms ◽  
Evolutionary Processes ◽  
Host Animal ◽  
Host Environment ◽  
The Rich

Microorganisms are present at most imaginable sites on the planet, and have evolved to occupy these ecological niches successfully. A host animal is simply another ecological niche to be occupied. This chapter describes how the ability to cause disease may in some cases be an accidental bystander event, or it may be the result of evolutionary processes that have led to specific mechanisms allowing the pathogen to exploit the rich source of nutrients present in the host, and then be transmitted to another fresh host. Pathogenicity often relies on a series of steps, with specific and often distinct mechanisms operating at each of them. Some types of pathogen must adapt to the host environment by altering gene expression, and most must retain the ability to be transmitted readily between hosts.

Effect of Ecological Pressures on Brains: Examples from Avian Neuroethology and General Meanings

1998 ◽  
Vol 53 (7-8) ◽  
pp. 560-581 ◽  
Author(s):  
Hermann Wagner ◽  
Harald Luksch
Keyword(s):  
Ecological Niche ◽  
Bird Song ◽  
Avian Species ◽  
Ecological Niches ◽  
Ecological Situation ◽  
Life Styles ◽  
Attentional Switching ◽  
Food Storing ◽  
Barn Owls

Abstract Comparative neuroethological research emphasizes that brains of animals have been shaped by the specific demands and constraints imposed by the ecological niche that a species occupies. Since avian species have developed very diverse life styles and occupy extreme ecological niches, bird brains should show many specializations, which may be revealed in species that have survived under high ecological pressures. In this paper, we will give several examples of adaptations, in which we are able to correlate structural and physiological spe­cializations to the specific ecological demands: adaptations found to nocturnal hunting in barn owls, the characteristics of bird song and its underlying neurobiological correlates, retinopetal projections and their relation to peripheral attentional switching, looming detection, and adaptations related to memory capacities of food-storing birds. We stress especially that the analysis of the animal’s ecological situation is important in understanding the factors that shaped both behavior and the neuronal substrate.

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