Ecology

2021 ◽  
pp. 417-452
Author(s):  
Paul Schmid-Hempel
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Infectious Diseases ◽  
Food Webs ◽  
Competitive Ability ◽  
Apparent Competition ◽  
Ecological Communities ◽  
Disease Emergence ◽  
Animal Reservoir ◽  
Transient Structure

Host ecological characteristics, such as body size, longevity, or social living, affect parasitism. Host populations can be regulated in size by their parasites; they can even drive host populations to extinction, usually after hosts have been weakened by other factors. Parasites, therefore, threaten endangered populations and species. Parasites also affect host ecological communities and food webs via effects on competitive ability or with apparent competition. In diverse host communities, infectious diseases become ‘diluted’. Parasite ecological communities seem to have a variable and transient structure; no universal explanation for the observed patterns exists. Host migration can transfer parasites to new areas or leave parasites behind. Disease emergence from an animal reservoir (zoonoses) is especially important. Many human diseases have such an origin, and these have repeatedly caused major epidemics. Climate change will also affect parasitism; however, the direction of change is rather complex and depends on the particular systems.

scholarly journals Warming and nitrogen affect size structuring and density dependence in a host–parasitoid food web

2012 ◽  
Vol 367 (1605) ◽  
pp. 3033-3041 ◽  
Author(s):  
Claudio de Sassi ◽  
Phillip P. A. Staniczenko ◽  
Jason M. Tylianakis
Keyword(s):  
Body Size ◽  
Food Web ◽  
Food Webs ◽  
Global Changes ◽  
Ecological Communities ◽  
Food Web Structure ◽  
Bottom Up ◽  
Mediated Effects ◽  
Web Structure ◽  
Nitrogen Treatments

Body size is a major factor constraining the trophic structure and functioning of ecological communities. Food webs are known to respond to changes in basal resource abundance, and climate change can initiate compounding bottom-up effects on food-web structure through altered resource availability and quality. However, the effects of climate and co-occurring global changes, such as nitrogen deposition, on the density and size relationships between resources and consumers are unknown, particularly in host–parasitoid food webs, where size structuring is less apparent. We use a Bayesian modelling approach to explore the role of consumer and resource density and body size on host–parasitoid food webs assembled from a field experiment with factorial warming and nitrogen treatments. We show that the treatments increased resource (host) availability and quality (size), leading to measureable changes in parasitoid feeding behaviour. Parasitoids interacted less evenly within their host range and increasingly focused on abundant and high-quality (i.e. larger) hosts. In summary, we present evidence that climate-mediated bottom-up effects can significantly alter food-web structure through both density- and trait-mediated effects.

Multivariate Climate Change Can Favor Large Herbivore Body Size in Food Webs

2018 ◽  
Vol 191 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Lauren M. Smith-Ramesh ◽  
Adam E. Rosenblatt ◽  
Oswald J. Schmitz
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Food Webs ◽  
Large Herbivore

scholarly journals Climate change in size-structured ecosystems

2012 ◽  
Vol 367 (1605) ◽  
pp. 2903-2912 ◽  
Author(s):  
Ulrich Brose ◽  
Jennifer A. Dunne ◽  
Jose M. Montoya ◽  
Owen L. Petchey ◽  
Florian D. Schneider ◽  
...  
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Size Structure ◽  
The Body ◽  
Size Distributions ◽  
Ecological Communities ◽  
Average Temperature ◽  
Mechanistic Approach ◽  
Effects Of Temperature ◽  
Future Consequences

One important aspect of climate change is the increase in average temperature, which will not only have direct physiological effects on all species but also indirectly modifies abundances, interaction strengths, food-web topologies, community stability and functioning. In this theme issue, we highlight a novel pathway through which warming indirectly affects ecological communities: by changing their size structure (i.e. the body-size distributions). Warming can shift these distributions towards dominance of small- over large-bodied species. The conceptual, theoretical and empirical research described in this issue, in sum, suggests that effects of temperature may be dominated by changes in size structure, with relatively weak direct effects. For example, temperature effects via size structure have implications for top-down and bottom-up control in ecosystems and may ultimately yield novel communities. Moreover, scaling up effects of temperature and body size from physiology to the levels of populations, communities and ecosystems may provide a crucially important mechanistic approach for forecasting future consequences of global warming.

scholarly journals Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pianpian Wu ◽  
Martin J. Kainz ◽  
Fernando Valdés ◽  
Siwen Zheng ◽  
Katharina Winter ◽  
...  
Keyword(s):  
Climate Change ◽  
Fatty Acids ◽  
Organic Matter ◽  
Food Webs ◽  
Essential Fatty Acids ◽  
Trophic Levels ◽  
Climate Change Scenarios ◽  
Essential Nutrients ◽  
Aquatic Food Webs ◽  
Aquatic Food

AbstractClimate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of food webs (i.e. seston; the most edible plankton size for zooplankton) in subalpine lake ecosystems. The interaction of higher temperature and tDOM increased the burden of MeHg in seston (< 40 μm) and larger sized plankton (microplankton; 40–200 μm), while the MeHg content per unit biomass remained stable. However, PUFA decreased in seston, but increased in microplankton, consisting mainly of filamentous algae, which are less readily bioavailable to zooplankton. We revealed elevated dietary exposure to MeHg, yet decreased supply of dietary PUFA to aquatic consumers with increasing temperature and tDOM supply. This experimental study provides evidence that the overall food quality at the base of aquatic food webs deteriorates during ongoing climate change scenarios by increasing the supply of toxic MeHg and lowering the dietary access to essential nutrients of consumers at higher trophic levels.

scholarly journals Chest beats as an honest signal of body size in male mountain gorillas (Gorilla beringei beringei)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Edward Wright ◽  
Sven Grawunder ◽  
Eric Ndayishimiye ◽  
Jordi Galbany ◽  
Shannon C. McFarlin ◽  
...  
Keyword(s):  
Body Size ◽  
Competitive Ability ◽  
Dominance Rank ◽  
Male Body ◽  
Honest Signal ◽  
Sexual Competition ◽  
Mountain Gorillas ◽  
Temporal Characteristics ◽  
Gorilla Beringei Beringei ◽  
Vocal Signals

AbstractAcoustic signals that reliably indicate body size, which usually determines competitive ability, are of particular interest for understanding how animals assess rivals and choose mates. Whereas body size tends to be negatively associated with formant dispersion in animal vocalizations, non-vocal signals have received little attention. Among the most emblematic sounds in the animal kingdom is the chest beat of gorillas, a non-vocal signal that is thought to be important in intra and inter-sexual competition, yet it is unclear whether it reliably indicates body size. We examined the relationship among body size (back breadth), peak frequency, and three temporal characteristics of the chest beat: duration, number of beats and beat rate from sound recordings of wild adult male mountain gorillas. Using linear mixed models, we found that larger males had significantly lower peak frequencies than smaller ones, but we found no consistent relationship between body size and the temporal characteristics measured. Taken together with earlier findings of positive correlations among male body size, dominance rank and reproductive success, we conclude that the gorilla chest beat is an honest signal of competitive ability. These results emphasize the potential of non-vocal signals to convey important information in mammal communication.

scholarly journals Effects of Infectious Diseases on Population Dynamics of Marine Organisms in Chesapeake Bay

2021 ◽  
Author(s):  
Jerelle A. Jesse ◽  
M. Victoria Agnew ◽  
Kohma Arai ◽  
C. Taylor Armstrong ◽  
Shannon M. Hood ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Infectious Diseases ◽  
Chesapeake Bay ◽  
Eastern Oyster ◽  
Marine Organisms ◽  
Ecosystem Dynamics ◽  
Climate Change Effects ◽  
Pathogen Dynamics ◽  
Growth And Reproduction

AbstractDiseases are important drivers of population and ecosystem dynamics. This review synthesizes the effects of infectious diseases on the population dynamics of nine species of marine organisms in the Chesapeake Bay. Diseases generally caused increases in mortality and decreases in growth and reproduction. Effects of diseases on eastern oyster (Crassostrea virginica) appear to be low in the 2000s compared to effects in the 1980s–1990s. However, the effects of disease were not well monitored for most of the diseases in marine organisms of the Chesapeake Bay, and few studies considered effects on growth and reproduction. Climate change and other anthropogenic effects are expected to alter host-pathogen dynamics, with diseases of some species expected to worsen under predicted future conditions (e.g., increased temperature). Additional study of disease prevalence, drivers of disease, and effects on population dynamics could improve fisheries management and forecasting of climate change effects on marine organisms in the Chesapeake Bay.

Preparedness 3.0: Addressing the Future

2015 ◽  
Vol 9 (6) ◽  
pp. 728-729 ◽  
Author(s):  
Georges C. Benjamin
Keyword(s):  
Public Health ◽  
Climate Change ◽  
Social Media ◽  
Infectious Diseases ◽  
Extreme Weather ◽  
Common Occurrence ◽  
Public Health Preparedness ◽  
Public Health Emergencies ◽  
State Sponsorship ◽  
The Future

ABSTRACTThe last 14 years has taught us that that we are facing a new reality; a reality in which public health emergencies are a common occurrence. Today, we live in a world with dangerous people without state sponsorship who are an enormous threat to our safety; one where emerging and reemerging infectious diseases are waiting to break out; a world where the benefits of globalization in trade, transportation, and social media brings threats to our communities faster and with a greater risk than ever before. Even climate change has entered into the preparedness equation, bringing with it the forces of nature in the form of extreme weather and its complications. (Disaster Med Public Health Preparedness. 2015;9:728–729)

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