scholarly journals Physiology provides a window into how the multi-stressor environment contributes to amphibian declines

2020 ◽  
pp. 165-182
Author(s):  
Michel E.B. Ohmer ◽  
Lesley A. Alton ◽  
Rebecca L. Cramp
Keyword(s):  
Immune Function ◽  
Fungal Pathogens ◽  
Biodiversity Loss ◽  
Amphibian Declines ◽  
Stress Physiology ◽  
Amphibian Conservation ◽  
Environmental Drivers ◽  
Amphibian Disease ◽  
And Shifts ◽  
Conservation And Management

The amphibian disease chytridiomycosis, caused by two fungal pathogens in the genus Batrachochytrium, has caused the greatest vertebrate biodiversity loss due to disease in recorded history. Both the pathogens and their amphibian hosts are impacted by biotic and abiotic conditions that are rapidly changing due to anthropogenic causes, challenging our understanding of how the host–pathogen relationship will shift in the future. By examining this problem through a physiological lens, we can elucidate the mechanisms driving increased susceptibility to disease. This chapter first examines the physiological tools that can be used by amphibian biologists to measure aspects of immune function, stress physiology, and energy expenditure, and the main environmental drivers of these physiological shifts. Then, we explore case studies that have linked environmental change, immune function, and shifts in disease susceptibility to inform amphibian conservation and management.

scholarly journals Effects of ultraviolet-B radiation on physiology, immune function and survival is dependent on temperature: implications for amphibian declines

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Niclas U Lundsgaard ◽  
Rebecca L Cramp ◽  
Craig E Franklin
Keyword(s):  
Low Temperature ◽  
Immune Function ◽  
Disease Susceptibility ◽  
Environmental Changes ◽  
Amphibian Declines ◽  
Ultraviolet B ◽  
Environmental Drivers ◽  
Conservation Strategies ◽  
Ultraviolet B Radiation ◽  
Mechanistic Basis

Abstract Multiple environmental changes are thought to be contributing to the widespread decline of amphibians in montane regions, but interactions between drivers of decline are not well understood. It has been proposed previously that elevated ultraviolet-B radiation (UBVR) and low temperatures may interact in their negative effects on health, immune function and disease susceptibility in exposed amphibians. In the present study, we chronically exposed larvae of the striped-marsh frog (Limnodynastes peronii) to a factorial combination of high and low UVBR and high and low temperature to assess interactive effects on growth, survival and indices of immune function. The high UVBR treatment reduced growth and survival of larvae compared to the low UVBR treatment at both temperatures, but the effects were significantly enhanced at low temperature. High UVBR exposure also induced a chronic inflammatory response as evidenced by an increase in the leucocyte proportion of total cells and altered the ratio of neutrophils to lymphocytes in the blood, highlighting a potential mechanistic basis for increased disease susceptibility in amphibians living at high altitudes. Our findings stress the importance of investigating environmental factors in combination when assessing their effects and highlight the mechanistic basis for how key environmental drivers in montane regions affect amphibian health. Continuation of this work is necessary for the development of targeted conservation strategies that tackle the root causes of montane amphibian declines.

Contrasting research approaches to managing mistletoes in commercial forests and wooded pasturesThis minireview is one of a collection of papers based on a presentation from the Stem and Shoot Fungal Pathogens and Parasitic Plants: the Values of Biological Diversity session of the XXII International Union of Forestry Research Organization World Congress meeting held in Brisbane, Queensland, Australia, in 2005.

Botany ◽  
2009 ◽  
Vol 87 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Nick Reid ◽  
Simon F. Shamoun
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Biological Diversity ◽  
Management Strategies ◽  
Biodiversity Loss ◽  
Classical Biological Control ◽  
Dwarf Mistletoe ◽  
Silvicultural Treatments ◽  
Inundative Biological Control

Many mistletoe species are pests in agricultural and forest ecosystems throughout the world. Mistletoes are unusual “weeds” as they are generally endemic to areas where they achieve pest status and, therefore, classical biological control and broad-scale herbicidal control are usually impractical. In North American coniferous forests, dwarf mistletoe ( Arceuthobium spp.) infection results in major commercial losses and poses a public liability in recreation settings. Hyperparasitic fungi have potential as biological control agents of dwarf mistletoe, including species which attack shoots, berries, and the endophytic systems of dwarf mistletoe. Development of an inundative biological control strategy will be useful in situations where traditional silvicultural control is impractical or undesirable. In southern Australia, farm eucalypts are often attacked and killed by mistletoes ( Amyema spp.) in grazed landscapes where tree decline and biodiversity loss are major forms of land degradation. Although long-term strategies to achieve a balance between mistletoe and host abundance are promoted, many graziers want short-term options to treat severely infected trees. Recent research has revisited the efficiency and efficacy of silvicultural treatments and selective herbicides in appropriate situations. The results of recent research on these diverse management strategies in North America and Australia are summarized.

Cognitively Based Compassion Training

2017 ◽  
Author(s):  
Jennifer S. Mascaro ◽  
Lobsang Tenzin Negi ◽  
Charles L. Raison
Keyword(s):  
Immune Function ◽  
Neural Activity ◽  
Well Being ◽  
Stress Physiology ◽  
Future Research ◽  
Beneficial Impact ◽  
The Brain ◽  
Health And Well Being ◽  
Initial Research

Recent research has examined the beneficial impact of kindness-based meditation practices, including cognitively-based compassion training (CBCT). Here we provide a theoretical and practical account of CBCT and review the emerging evidence that it affects the brain and body in ways that are relevant for health. Initial research demonstrated that CBCT alters immune function and stress physiology, and augments empathy as well as the neural activity supporting it. More recent studies indicate that CBCT is differentially effective, depending on the population that practices. We suggest directions for future research to best examine the apparently complex effects of CBCT on health and well-being.

Applying GLOBIO at Different Geographical Levels

2011 ◽  
pp. 150-170 ◽  
Author(s):  
Rob Alkemade ◽  
Jan Janse ◽  
Wilbert van Rooij ◽  
Yongyut Trisurat
Keyword(s):  
River Flow ◽  
Human Impacts ◽  
Biodiversity Loss ◽  
Environmental Drivers ◽  
Infrastructure Development ◽  
Response Options ◽  
Biodiversity Changes ◽  
Original Species ◽  
Terrestrial Biodiversity ◽  
Meta Analyses

Biodiversity is decreasing at high rates due to a number of human impacts. The GLOBIO3 model has been developed to assess human-induced changes in terrestrial biodiversity at national, regional, and global levels. Recently, GLOBIO-aquatic has been developed for inland aquatic ecosystems. These models are built on simple cause–effect relationships between environmental drivers and biodiversity, based on meta-analyses of literature data. The mean abundance of original species relative to their abundance in undisturbed ecosystems (MSA) is used as the indicator for biodiversity. Changes in drivers are derived from the IMAGE 2.4 model. Drivers considered are land-cover change, land-use intensity, fragmentation, climate change, atmospheric nitrogen deposition, excess of nutrients, infrastructure development, and river flow deviation. GLOBIO addresses (1) the impacts of environmental drivers on MSA and their relative importance; (2) expected trends under various future scenarios; and (3) the likely effects of various policy-response options. The changes in biodiversity can be assessed by the GLOBIO model at different geographical levels. The application depends largely on the availability of future projections of drivers. From the different analyses at the different geographical levels, it can be seen that biodiversity loss, in terms of MSA, will continue, and current policies may only reduce the rate of loss.

scholarly journals Biodiversity and conservation of terricolous lichens and bryophytes in continental lowlands of northern Italy: the role of different dry habitat types

2020 ◽  
Vol 29 (13) ◽  
pp. 3533-3550
Author(s):  
Gabriele Gheza ◽  
Silvia Assini ◽  
Chiara Lelli ◽  
Lorenzo Marini ◽  
Helmut Mayrhofer ◽  
...  
Keyword(s):  
Species Richness ◽  
Vegetation Dynamics ◽  
Biodiversity Loss ◽  
Northern Italy ◽  
Environmental Drivers ◽  
Dry Grasslands ◽  
Species Of Conservation Concern ◽  
Terricolous Lichens ◽  
Landscape Scales

Abstract In dry habitats of European lowlands terricolous lichens and bryophytes are almost neglected in conservation practises, even if they may strongly contribute to biodiversity. This study aims at (a) testing the role of heathlands, acidic and calcareous dry grasslands for lichen and bryophyte diversity and conservation in lowland areas of northern Italy characterized by high human impact and habitat fragmentation; (b) detecting the effect of environmental drivers and vegetation dynamics on species richness and composition. Lichens, bryophytes, vascular plants, and environmental variables were recorded in 287 circular plots for 75 sites. Our results indicate that heathlands, acidic and calcareous dry grasslands host peculiar terricolous lichen and bryophyte communities that include several species of conservation concern. Thus, each habitat provides a complementary contribution to lichen and bryophyte diversity in continental lowland landscapes. Furthermore, in each habitat different factors drive species richness and composition with contrasting patterns between lichens and bryophytes. In terms of conservation, our results indicate that management of lowland dry habitats should act at both local and landscape scales. At local scale, vegetation dynamics should be controlled in order to avoid biodiversity loss due to vegetation dynamics and wood encroachment. At the landscape scale, patches of all the three habitats should be maintained to maximize regional diversity.

scholarly journals Tracking, Synthesizing, and Sharing Global Batrachochytrium Data at AmphibianDisease.org

2021 ◽  
Vol 8 ◽  
Author(s):  
Michelle S. Koo ◽  
Vance T. Vredenburg ◽  
John B. Deck ◽  
Deanna H. Olson ◽  
Kathryn L. Ronnenberg ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
New Technologies ◽  
Abiotic Factors ◽  
Emerging Infectious Diseases ◽  
Host Community ◽  
Biological Knowledge ◽  
Published Data ◽  
Wildlife Diseases ◽  
Amphibian Disease ◽  
Metadata Standards

Emerging infectious diseases have been especially devastating to amphibians, the most endangered class of vertebrates. For amphibians, the greatest disease threat is chytridiomycosis, caused by one of two chytridiomycete fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Research over the last two decades has shown that susceptibility to this disease varies greatly with respect to a suite of host and pathogen factors such as phylogeny, geography (including abiotic factors), host community composition, and historical exposure to pathogens; yet, despite a growing body of research, a comprehensive understanding of global chytridiomycosis incidence remains elusive. In a large collaborative effort, Bd-Maps was launched in 2007 to increase multidisciplinary investigations and understanding using compiled global Bd occurrence data (Bsal was not discovered until 2013). As its database functions aged and became unsustainable, we sought to address critical needs utilizing new technologies to meet the challenges of aggregating data to facilitate research on both Bd and Bsal. Here, we introduce an advanced central online repository to archive, aggregate, and share Bd and Bsal data collected from around the world. The Amphibian Disease Portal (https://amphibiandisease.org) addresses several critical community needs while also helping to build basic biological knowledge of chytridiomycosis. This portal could be useful for other amphibian diseases and could also be replicated for uses with other wildlife diseases. We show how the Amphibian Disease Portal provides: (1) a new repository for the legacy Bd-Maps data; (2) a repository for sample-level data to archive datasets and host published data with permanent DOIs; (3) a flexible framework to adapt to advances in field, laboratory, and informatics technologies; and (4) a global aggregation of Bd and Bsal infection data to enable and accelerate research and conservation. The new framework for this project is built using biodiversity informatics best practices and metadata standards to ensure scientific reproducibility and linkages across other biological and biodiversity repositories.

Coral reef fishes reveal strong divergence in the prevalence of traits along the global diversity gradient

2021 ◽  
Vol 288 (1961) ◽  
Author(s):  
V. Parravicini ◽  
M. G. Bender ◽  
S. Villéger ◽  
F. Leprieur ◽  
L. Pellissier ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Species Distribution Models ◽  
Human Impacts ◽  
Biodiversity Loss ◽  
Reef Fishes ◽  
Climatic Conditions ◽  
Taxonomic Structure ◽  
Distribution Models ◽  
Diversity Gradient ◽  
And Shifts

Coral reefs are experiencing declines due to climate change and local human impacts. While at a local scale these impacts induce biodiversity loss and shifts in community structure, previous biogeographical analyses recorded consistent taxonomic structure of fish communities across global coral reefs. This suggests that regional communities represent a random subset of the global species and traits pool, whatever their species richness. Using distributional data on 3586 fish species and latest advances in species distribution models, we show marked gradients in the prevalence of size classes and diet categories across the biodiversity gradient. This divergence in trait structure is best explained by reef isolation during past unfavourable climatic conditions, with large and piscivore fishes better represented in isolated areas. These results suggest the risk of a global community re-organization if the ongoing climate-induced reef fragmentation is not halted.

scholarly journals Exotic species invasions undermine regional functional diversity of freshwater fish

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marco Milardi ◽  
Anna Gavioli ◽  
Janne Soininen ◽  
Giuseppe Castaldelli
Keyword(s):  
Exotic Species ◽  
Functional Diversity ◽  
Current Knowledge ◽  
Biodiversity Loss ◽  
Taxonomic Diversity ◽  
Environmental Drivers ◽  
Ecological Traits ◽  
Species Invasions ◽  
Temporal And Spatial ◽  
Fine Resolution

AbstractExotic species invasions often result in native biodiversity loss, i.e. a lower taxonomic diversity, but current knowledge on invasions effects underlined a potential increase of functional diversity. We thus explored the connections between functional diversity and exotic species invasions, while accounting for their environmental drivers, using a fine-resolution large dataset of Mediterranean stream fish communities. While functional diversity of native and exotic species responded similarly to most environmental constraints, we found significant differences in the effects of altitude and in the different ranking of constraints. These differences suggest that invasion dynamics could play a role in overriding some major environmental drivers. Our results also showed that a lower diversity of ecological traits in communities (about half of less disturbed communities) corresponded to a high invasion degree, and that the exotic component of communities had typically less diverse ecological traits than the native one, even when accounting for stream order and species richness. Overall, our results suggest that possible outcomes of severe exotic species invasions could include a reduced functional diversity of invaded communities, but analyzing data with finer ecological, temporal and spatial resolutions would be needed to pinpoint the causal relationship between invasions and functional diversity.

scholarly journals Infectious disease threats to amphibian conservation

2018 ◽  
Vol 27 (Supplement) ◽  
pp. 81-90
Author(s):  
A.A. Cunningham
Keyword(s):  
Infectious Disease ◽  
Batrachochytrium Dendrobatidis ◽  
Biodiversity Loss ◽  
Amphibian Conservation ◽  
Disease Spread ◽  
Population Declines ◽  
Amphibian Species ◽  
Late 20Th Century ◽  
Amphibian Population ◽  
In The Wild

The unexplained decline of amphibian populations across the world was first recognised in the late 20th century. When investigated, most of these “enigmatic” declines have been shown to be due to one of two types of infectious disease: ranavirosis caused by infection with FV3-like ranavirus or with common midwife toad virus, or chytridiomycosis caused by infection with Batrachochytrium dendrobatidis or B. salamandrivorans. In all cases examined, infection has been via the human-mediated introduction of the pathogen to a species or population in which it has not naturally co-evolved. While ranaviruses and B. salamandrivorans have caused regionally localised amphibian population declines in Europe, the chytrid fungus, B. dendrobatidis, has caused catastrophic multi-species amphibian population declines and species extinctions globally. These diseases have already caused the loss of amphibian biodiversity, and over 40% of known amphibian species are threatened with extinction. If this biodiversity loss is to be halted, it is imperative that regulations are put in place – and enforced – to prevent the spread of known and yet-to-be discovered amphibian pathogens. Also, it is incumbent on those who keep or study amphibians to take measures to minimise the risk of disease spread, including from captive animals to those in the wild.

scholarly journals Archaeobotanical evidence for a massive loss of epiphyte species richness during industrialization in southern England

2011 ◽  
Vol 278 (1724) ◽  
pp. 3482-3489 ◽  
Author(s):  
Christopher J. Ellis ◽  
Rebecca Yahr ◽  
Brian J. Coppins
Keyword(s):  
Species Richness ◽  
Biodiversity Loss ◽  
Reference Points ◽  
Environmental Drivers ◽  
Southern England ◽  
Vernacular Buildings ◽  
Industrial Landscapes ◽  
Post Industrial ◽  
First Time ◽  
Epiphyte Species

This paper describes a novel archaeological resource—preserved epiphytes on the timber structure of vernacular buildings—used, to our knowledge, for the first time to quantify a loss of biodiversity between pre-industrial and post-industrial landscapes. By matching the confirmed occurrence of epiphyte species for the pre-industrial period, with a statistical likelihood for their absence in the present-day landscape (post-1960), we robustly identified species that have been extirpated across three contrasting regions in southern England. First, the scale of biodiversity loss observed—up to 80 per cent of epiphytes—severely challenges biodiversity targets and environmental baselines that have been developed using reference points in the post-industrial period. Second, we examined sensitivity in the present-day distribution of extirpated species, explained by three environmental drivers: (i) pollution regime, (ii) extent of ancient woodland, and (iii) climatic setting. Results point to an interacting effect between the pollution regime (sulphur dioxide) and changed woodland structure, leading to distinctive regional signatures in biodiversity loss.

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