Environmental control of community organisation on ocean-exposed sandy beaches

2013 ◽  
Vol 64 (2) ◽  
pp. 119 ◽  
Author(s):  
Thomas A. Schlacher ◽  
Luke Thompson

Models of faunal communities on open-coast beaches emphasise the primacy of environmental conditions in determining species richness and abundance. What remains unresolved under this ‘physical-control paradigm’ includes the following two aspects: (1) how habitat properties relate to structural traits of communities; and (2) how environmental conditions shape communities when habitat properties change over time. Here, we test these by modelling the relationship between a broad range of environmental drivers and assemblage structure. Our models draw on a sizeable dataset (15 600 cores collected over 4 years) of benthic invertebrates from beaches in eastern Australia; we also include a test of whether human disturbance (vehicles) alters the relationships between environmental predictors and faunal communities. A suite of physical factors, comprising habitat features (i.e. moisture level, grain size, beach slope) and wave parameters, explained variation in community structure. Novel aspects are the role of sea-surface temperature (SST) as a driver of biological structure on beaches, and that human impacts can override the sediment–animal relationships that are normally important. More generally, theoretical and empirical models of beach-community organisation should incorporate multiple environmental drivers, include broader structural aspect of assemblages, and recognise the role of human habitat alterations in shaping these fauna–environment links.

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.


Author(s):  
Natalia Bryniarska-Kubiak ◽  
Andrzej Kubiak ◽  
Małgorzata Lekka ◽  
Agnieszka Basta-Kaim

AbstractNervous system diseases are the subject of intensive research due to their association with high mortality rates and their potential to cause irreversible disability. Most studies focus on targeting the biological factors related to disease pathogenesis, e.g. use of recombinant activator of plasminogen in the treatment of stroke. Nevertheless, multiple diseases such as Parkinson’s disease and Alzheimer’s disease still lack successful treatment. Recently, evidence has indicated that physical factors such as the mechanical properties of cells and tissue and topography play a crucial role in homeostasis as well as disease progression. This review aims to depict these factors’ roles in the progression of nervous system diseases and consequently discusses the possibility of new therapeutic approaches. The literature is reviewed to provide a deeper understanding of the roles played by physical factors in nervous system disease development to aid in the design of promising new treatment approaches. Graphic abstract


2002 ◽  
Vol 15 (2) ◽  
pp. 205 ◽  
Author(s):  
Christina Flann ◽  
Pauline Y. Ladiges ◽  
Neville G. Walsh

A study of morphological variation in Leptorhynchos squamatus (Labill.) Less. across its range in south-eastern Australia was undertaken to test the hypothesis that L. squamatus includes two taxa. Phenetic pattern analyses of both field-collected and herbarium specimens on the basis of morphology confirmed two major groups. Bract, cypsela, pappus bristle and leaf characters were particularly important in separating the two groups. The taxa are separated by altitude differences with one being a low-altitude plant found in many habitats and the other being a high-altitude taxon that is a major component of alpine meadows. Lowland plants have dark bract tips, fewer and wider pappus bristles than alpine plants, papillae on the cypselas and more linear leaves. A somewhat intermediate population from the Major Mitchell Plateau in the Grampians shows some alpine and some lowland characters but is included in the lowland taxon. Seeds from five populations (two alpine, two lowland and Major Mitchell) were germinated and plants grown for 18 weeks under four controlled sets of environmental conditions. The experiment showed that leaf size and some other characters are affected by environmental conditions, but that there are underlying genetic differences between the lowland and alpine forms. Leptorhynchos squamatus subsp. alpinus Flann is described here to accommodate the highland taxon.


1985 ◽  
Vol 66 (4) ◽  
pp. 318-318
Author(s):  
L. V. Chernetsova ◽  
A. G. Ibragimova

The comparative analysis of treatment of 76 patients with rheumatoid arthritis using electromagnetic waves of the decimeter range and lithium electrophoresis, depending on the activity of the process and the type of drug therapy.


2021 ◽  
Vol 18 (1) ◽  
pp. 52-65
Author(s):  
P. N. Mikheev

The article discusses issues related to the impact of climate change on the objects of the oil and gas industry. The main trends in climate change on a global and regional (on the territory of Russian Federation) scale are outlined. Possible approaches to the identification and assessment of climate risks are discussed. The role of climatic risks as physical factors at various stages of development and implementation of oil and gas projects is shown. Based on the example of oil and gas facilities in the Tomsk region, a qualitative assessment of the level of potential risk from a weather and climatic perspective is given. Approaches to creating a risk management and adaptation system to climate change are presented.


2021 ◽  
Author(s):  
Steven Most ◽  
Kim Curby

Although physical salience looms large in the attentional capture literature, stimuli can also capture attention via salience deriving from non-physical factors. Such psychological salience can stem, for example, from the emotional resonance of stimuli or their relevance to a person’s expertise. We consider how insights from a recently proposed framework for attentional capture can be used to advance theory and drive research on the role of emotion-driven attentional biases in clinical disorders and on how attentional allocation changes with the development of perceptual expertise. In return, we wonder how their common framework can be enriched through considerations of psychological salience.


2017 ◽  
pp. 71
Author(s):  
Alma Orozco-Segovia

Phytochrome is the plant pigment which participate in several developmental processes regulated by light. In recent years this pigment has been associated with the detection of the environmental conditions but there is still a gap of information concerning the physioecological role of the pigment. In this paper the knowledge of the role of phytochrome on seed photoblastism is analysed based on several recent works done on the subject mainly with pioneer rain forest plants from Los Tuxtlas, Veracruz.


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