scholarly journals Glacier caves: a globally threatened subterranean biome

2021 ◽  
Vol 83 (2) ◽  
pp. 66-70
Author(s):  
Francis Howarth
Keyword(s):  
Global Warming ◽  
Physical Environment ◽  
Ecological Studies ◽  
Invertebrate Fauna ◽  
Common Features ◽  
Endangered Ecosystems

Caves and cave-like voids are common features within and beneath glaciers. The physical environment is harsh and extreme, and often considered barren and devoid of life. However, accumulating evidence indicates that these caves may support a diverse invertebrate fauna with species endemic to each region. As glaciers continue to disappear at an alarming rate due to global warming, they take their largely unknown fauna with them. Thus, glacier caves may harbor one of the most endangered ecosystems globally, and yet their biodiversity is among the least studied or known. Faunal surveys and ecological studies are urgently needed before all examples are lost.

The Arctic: A Very Short Introduction

2021 ◽  
Author(s):  
Klaus Dodds ◽  
Jamie Woodward
Keyword(s):  
Global Warming ◽  
Physical Environment ◽  
Economic Change ◽  
The Arctic ◽  
Short Introduction ◽  
Changing Environment ◽  
Key Issues ◽  
Uncertain Future

The Arctic: A Very Short Introduction provides an account of the Arctic, its physical environment, and its people. The Arctic is demanding global attention as it warms, melts, and thaws in a manner that threatens not just its 4 million inhabitants, but the whole planet. The reduction of the Arctic to its changing environment would ignore the complexities of the region and its potential. This VSI explores key issues facing the region today, from geopolitics to global warming. It examines the causes and effects of cultural, physical, ecological, political, and economic change in the Arctic, and considers its uncertain future.

IV.—Some Ecological Aspects of the Intertidal Area of the Estuary of the Aberdeenshire Dee

1941 ◽  
Vol 60 (1) ◽  
pp. 107-139 ◽  
Author(s):  
Alec Milne
Keyword(s):  
Physical Environment ◽  
Salt Content ◽  
Magnesium Content ◽  
Summer Temperature ◽  
Light Penetration ◽  
Ecological Studies ◽  
Intertidal Area ◽  
Ecological Aspects ◽  
Total Salt Content ◽  
Homogeneous Environment

In the seaward direction in an estuary there are usually the following main gradients:—(a) Increase in osmotic pressure (total salt content, especially chlorides).(b) Increase in calcium and magnesium content.(c) Increase in alkalinity.(d) Increase in winter and decrease in summer temperature.(e) Increase in light penetration.There are other gradients of less importance. The first three are dependent on salinity. Thus, from the ecological standpoint, the three important physical observations relative to the study of estuarine life are the salinity, temperature, and light (silt content) gradients.Ecological studies are directed towards the elucidation of two types of problems:(i) Characteristics of the physical environment relevant to the distribution of specific forms of life.(ii) The growth of mixed populations and their interrelations in a homogeneous environment or in a physical gradient.The present study concerns itself especially with the former, and to a less extent with the latter.

Ecological Studies on a Lowland Evergreen Rain Forest on Maraca Island, Roraima, Brazil. I. Physical Environment, Forest Structure and Leaf Chemistry

1992 ◽  
Vol 80 (4) ◽  
pp. 689 ◽  
Author(s):  
J. Thompson ◽  
J. Proctor ◽  
V. Viana ◽  
W. Milliken ◽  
J. A. Ratter ◽  
...  
Keyword(s):  
Forest Structure ◽  
Physical Environment ◽  
Rain Forest ◽  
Leaf Chemistry ◽  
Ecological Studies

scholarly journals Community structure of invertebrate fauna in Central Chilean Rivers

2019 ◽  
Vol 31 ◽  
Author(s):  
Patricio De los Ríos ◽  
Gustavo Díaz ◽  
Jorge Gonzalez ◽  
Konrad Górski ◽  
Evelyn Habit
Keyword(s):  
Community Structure ◽  
Interspecific Competition ◽  
Niche Overlap ◽  
Null Models ◽  
Ecological Studies ◽  
Invertebrate Fauna ◽  
River Systems ◽  
Central Chile ◽  
Invertebrate Communities ◽  
Ecological Patterns

Abstract Aim River systems of Central Chile are short, steep and fast flowing. They are characterized by discharge regimes dominated by rainfall and snowmelt. Invertebrate fauna is highly endemic. This study aimed to describe the community structure of invertebrate in eight river systems in Central Chile (33-39°S) using species co-occurrence and niche sharing null models. Methods Invertebrate samples were collected from Central Chilean rivers (33-39°S), data were analyzed co-occurrence species and niche sharing null models for determine potential structuring patterns. Results The results revealed the presence of non-structured patterns in co-occurrence considering each site as well as all sites, that is most probably an effect of presence of many repeated species in the studied sites. Furthermore, we found the existence of niche overlap due to interspecific competition at each site and among all sites. The results obtained from these river systems corroborate observations from Chilean Patagonian Rivers. Conclusion This study contributes to understanding of biogeographical and ecological patterns of invertebrate communities in central Chilean Rivers and provide foundations for more complex ecological studies.

scholarly journals Impact of global warming on ENSO phase change

2006 ◽  
Vol 6 ◽  
pp. 103-110 ◽  
Author(s):  
W. Cabos Narvaez ◽  
F. Alvarez-Garcia ◽  
M. J. OrtizBeviá
Keyword(s):  
Global Warming ◽  
Phase Change ◽  
Heat Content ◽  
Tropical Pacific ◽  
Common Features ◽  
Clustering Technique ◽  
Physical Mechanisms ◽  
Enso Events ◽  
Ocean Atmosphere ◽  
The Tropical Pacific

Abstract. We compare the physical mechanisms involved in the generation and decay of ENSO events in a control (present day conditions) and Scenario (Is92a, IPCC 1996) simulations performed with the coupled ocean-atmosphere GCM ECHAM4-OPYC3. A clustering technique which objectively discriminates common features in the evolution of the Tropical Pacific Heat Content anomalies leading to the peak of ENSO events allows us to group into a few classes the ENSO events occurring in 240 years of data in the control and scenario runs. In both simulations, the composites of the groups show differences in the generation and development of ENSO. We present the changes in the statistics of the groups and explore the possible mechanisms involved.

Modelling ecosystem adaptation and dangerous rates of global warming

2019 ◽  
Vol 3 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Rebecca Millington ◽  
Peter M. Cox ◽  
Jonathan R. Moore ◽  
Gabriel Yvon-Durocher
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Diffusion Rate ◽  
Individual Species ◽  
Genetic Evolution ◽  
Rates Of Change ◽  
Rapid Climate Change ◽  
Warming Climate ◽  
Intraspecies Competition ◽  
High Trait

Abstract We are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).

An Application of the HFACS Method to Aviation Accidents in Africa

2016 ◽  
Vol 6 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Isaac Munene
Keyword(s):  
Human Factors ◽  
Physical Environment ◽  
Human Factor ◽  
Flight Training ◽  
African Countries ◽  
Causal Factors ◽  
Aviation Accidents ◽  
Factors Analysis ◽  
Adverse Weather ◽  
Decision Errors

Abstract. The Human Factors Analysis and Classification System (HFACS) methodology was applied to accident reports from three African countries: Kenya, Nigeria, and South Africa. In all, 55 of 72 finalized reports for accidents occurring between 2000 and 2014 were analyzed. In most of the accidents, one or more human factors contributed to the accident. Skill-based errors (56.4%), the physical environment (36.4%), and violations (20%) were the most common causal factors in the accidents. Decision errors comprised 18.2%, while perceptual errors and crew resource management accounted for 10.9%. The results were consistent with previous industry observations: Over 70% of aviation accidents have human factor causes. Adverse weather was seen to be a common secondary casual factor. Changes in flight training and risk management methods may alleviate the high number of accidents in Africa.

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