scholarly journals Environmental variability uncovers disruptive effects of species' interactions on population dynamics

2015 ◽  
Vol 282 (1812) ◽  
pp. 20151126 ◽  
Author(s):  
Sara Gudmundson ◽  
Anna Eklöf ◽  
Uno Wennergren
Keyword(s):  
Population Dynamics ◽  
White Noise ◽  
Food Webs ◽  
Species Interactions ◽  
Environmental Variability ◽  
Single Species ◽  
Ecological Communities ◽  
Species Response ◽  
To Come ◽  
Isolated Species

How species respond to changes in environmental variability has been shown for single species, but the question remains whether these results are transferable to species when incorporated in ecological communities. Here, we address this issue by analysing the same species exposed to a range of environmental variabilities when (i) isolated or (ii) embedded in a food web. We find that all species in food webs exposed to temporally uncorrelated environments (white noise) show the same type of dynamics as isolated species, whereas species in food webs exposed to positively autocorrelated environments (red noise) can respond completely differently compared with isolated species. This is owing to species following their equilibrium densities in a positively autocorrelated environment that in turn enables species–species interactions to come into play. Our results give new insights into species' response to environmental variation. They especially highlight the importance of considering both species' interactions and environmental autocorrelation when studying population dynamics in a fluctuating environment.

Host-Parasitoid Interactions

Ecology ◽  
2013 ◽  
Author(s):  
Jeffrey A. Harvey
Keyword(s):  
Population Dynamics ◽  
Food Webs ◽  
20Th Century ◽  
Host Species ◽  
Trophic Levels ◽  
Diverse Group ◽  
Ecological Communities ◽  
Major Focus ◽  
Species Identity ◽  
Wide Range

Insects are a highly diverse group due to their ability to exploit a wide range of niches. Each plant is attacked by multiple herbivores and these in turn may harbor a bewildering complexity of natural enemies, particularly parasitoids, which are often quite specialized in terms of the host species identity (and stage of attack) of their hosts. Furthermore, these parasitoids have their own parasitoids that attack them, meaning that food webs including these insects may go up to five trophic levels (or even more). Due to their diversity and strong link population dynamics, parasitoids comprise important aspects of ecological communities. Because of this and their potential as biocontrol agents, host-parasitoid dynamics have been a major focus of ecological and evolutionary study since the beginning of the 20th century.

scholarly journals The impacts of different management strategies and environmental forcing in ecological communities

2006 ◽  
Vol 273 (1600) ◽  
pp. 2491-2499 ◽  
Author(s):  
Katja Enberg ◽  
Mike S Fowler ◽  
Esa Ranta
Keyword(s):  
Species Interactions ◽  
Management Strategies ◽  
Single Species ◽  
Target Population ◽  
Population Management ◽  
Community Response ◽  
Ecological Communities ◽  
Target Species ◽  
Community Members ◽  
Environmental Forcing

Understanding the effects of population management on the community a target species belongs to is of key importance for successful management. It is known that the removal or extinction of a single species in a community may lead to extinctions of other community members. In our study, we assess the impacts of population management on competitive communities, studying the response of both locally stable and unstable communities of varying size (between four and 10 species) to three different management strategies; harvesting of a target species, harvesting with non-targeted catch, and stocking of the target species. We also studied the consequences of selecting target species with different relative abundances, as well as the effects of varying environmental conditions. We show here how the effects of management in competitive communities extend far beyond the target population. A crucial role is played by the underlying stability properties of the community under management. In general, locally unstable communities are more vulnerable to perturbation through management. Furthermore, the community response is shown to be sensitive to the relative density of the target species. Of considerable interest is the result that even a small (2.5%) increase in the population size of the target species through stocking may lead to extinction of other community members. These results emphasize the importance of considering and understanding multi-species interactions in population management.

scholarly journals Thermal acclimation of interactions: differential responses to temperature change alter predator–prey relationship

2012 ◽  
Vol 279 (1744) ◽  
pp. 4058-4064 ◽  
Author(s):  
Veronica S. Grigaltchik ◽  
Ashley J. W. Ward ◽  
Frank Seebacher
Keyword(s):  
Species Interactions ◽  
Prey Capture ◽  
Thermal Sensitivity ◽  
Single Species ◽  
Thermal Acclimation ◽  
Interspecific Difference ◽  
Ecological Communities ◽  
Predator Prey ◽  
Eastern Mosquitofish ◽  
Species Performance

Different species respond differently to environmental change so that species interactions cannot be predicted from single-species performance curves. We tested the hypothesis that interspecific difference in the capacity for thermal acclimation modulates predator–prey interactions. Acclimation of locomotor performance in a predator (Australian bass, Macquaria novemaculeata ) was qualitatively different to that of its prey (eastern mosquitofish, Gambusia holbrooki ). Warm (25°C) acclimated bass made more attacks than cold (15°C) acclimated fish regardless of acute test temperatures (10–30°C), and greater frequency of attacks was associated with increased prey capture success. However, the number of attacks declined at the highest test temperature (30°C). Interestingly, escape speeds of mosquitofish during predation trials were greater than burst speeds measured in a swimming arena, whereas attack speeds of bass were lower than burst speeds. As a result, escape speeds of mosquitofish were greater at warm temperatures (25°C and 30°C) than attack speeds of bass. The decline in the number of attacks and the increase in escape speed of prey means that predation pressure decreases at high temperatures. We show that differential thermal responses affect species interactions even at temperatures that are within thermal tolerance ranges. This thermal sensitivity of predator–prey interactions can be a mechanism by which global warming affects ecological communities.

scholarly journals Drifting Phenologies Cause Reduced Seasonality of Butterflies in Response to Increasing Temperatures

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 174 ◽  
Author(s):  
Zachariah Gezon ◽  
Rebekah Lindborg ◽  
Anne Savage ◽  
Jaret Daniels
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Single Species ◽  
Trophic Levels ◽  
Butterfly Species ◽  
Similar Species ◽  
Ecological Communities ◽  
Science Data ◽  
Data Set ◽  
Ecological Changes

Climate change has caused many ecological changes around the world. Altered phenology is among the most commonly observed effects of climate change, and the list of species interactions affected by altered phenology is growing. Although many studies on altered phenology focus on single species or on pairwise species interactions, most ecological communities are comprised of numerous, ecologically similar species within trophic groups. Using a 12-year butterfly monitoring citizen science data set, we aimed to assess the degree to which butterfly communities may be changing over time. Specifically, we wanted to assess the degree to which phenological sensitivities to temperature could affect temporal overlap among species within communities, independent of changes in abundance, species richness, and evenness. We found that warming winter temperatures may be associated with some butterfly species making use of the coldest months of the year to fly as adults, thus changing temporal co-occurrence with other butterfly species. Our results suggest that changing temperatures could cause immediate restructuring of communities without requiring changes in overall abundance or diversity. Such changes could have fitness consequences for individuals within trophic levels by altering competition for resources, as well as indirect effects mediated by species interactions across trophic levels.

Climate-associated trends and variability in ichthyoplankton phenology from the longest continuous larval fish time series on the east coast of the United States

2020 ◽  
Vol 650 ◽  
pp. 269-287
Author(s):  
WC Thaxton ◽  
JC Taylor ◽  
RG Asch
Keyword(s):  
United States ◽  
Environmental Variability ◽  
Larval Fish ◽  
Interspecific Interactions ◽  
River Estuary ◽  
Atlantic Multidecadal Oscillation ◽  
The United States ◽  
Larval Survival ◽  
Ecological Communities ◽  
Northerly Wind

As the effects of climate change become more pronounced, variation in the direction and magnitude of shifts in species occurrence in space and time may disrupt interspecific interactions in ecological communities. In this study, we examined how the fall and winter ichthyoplankton community in the Newport River Estuary located inshore of Pamlico Sound in the southeastern United States has responded to environmental variability over the last 27 yr. We relate the timing of estuarine ingress of 10 larval fish species to changes in sea surface temperature (SST), the Atlantic Multidecadal Oscillation, the North Atlantic Oscillation, wind strength and phenology, and tidal height. We also examined whether any species exhibited trends in ingress phenology over the last 3 decades. Species varied in the magnitude of their responses to all of the environmental variables studied, but most shared a common direction of change. SST and northerly wind strength had the largest impact on estuarine ingress phenology, with most species ingressing earlier during warm years and delaying ingress during years with strong northerly winds. As SST warms in the coming decades, the average date of ingress of some species (Atlantic croaker Micropogonias undulatus, summer flounder Paralichthys dentatus, pinfish Lagodon rhomboides) is projected to advance on the order of weeks to months, assuming temperatures do not exceed a threshold at which species can no longer respond through changes in phenology. These shifts in ingress could affect larval survival and growth since environmental conditions in the estuarine and pelagic nursery habitats of fishes also vary seasonally.

scholarly journals Evaluating Coexistence of Fish Species with Coastal Cutthroat Trout in Low Order Streams of Western Oregon and Washington, USA

Fishes ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Kyle D. Martens ◽  
Jason Dunham
Keyword(s):  
Pacific Northwest ◽  
Species Interactions ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
Single Species ◽  
The Pacific ◽  
Small Streams ◽  
Coastal Cutthroat Trout ◽  
Multiple Species ◽  
Low Order

When multiple species of fish coexist there are a host of potential ways through which they may interact, yet there is often a strong focus on studies of single species without considering these interactions. For example, many studies of forestry–stream interactions in the Pacific Northwest have focused solely on the most prevalent species: Coastal cutthroat trout. To examine the potential for interactions of other fishes with coastal cutthroat trout, we conducted an analysis of 281 sites in low order streams located on Washington’s Olympic Peninsula and along the central Oregon coast. Coastal cutthroat trout and juvenile coho salmon were the most commonly found salmonid species within these streams and exhibited positive associations with each other for both presence and density. Steelhead were negatively associated with the presence of coastal cutthroat trout as well as with coho salmon and sculpins (Cottidae). Coastal cutthroat trout most frequently shared streams with juvenile coho salmon. For densities of these co-occurring species, associations between these two species were relatively weak compared to the strong influences of physical stream conditions (size and gradient), suggesting that physical conditions may have more of an influence on density than species interactions. Collectively, our analysis, along with a review of findings from prior field and laboratory studies, suggests that the net effect of interactions between coastal cutthroat trout and coho salmon do not appear to inhibit their presence or densities in small streams along the Pacific Northwest.

Single-species models for many-species food webs

Nature ◽  
2002 ◽  
Vol 417 (6887) ◽  
pp. 541-543 ◽  
Author(s):  
W. W. Murdoch ◽  
B. E. Kendall ◽  
R. M. Nisbet ◽  
C. J. Briggs ◽  
E. McCauley ◽  
...  
Keyword(s):  
Food Webs ◽  
Single Species

scholarly journals Sustainable exploitation of temperate fish stocks

2009 ◽  
Vol 6 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Henrik Sparholt ◽  
Robin M. Cook
Keyword(s):  
Species Interactions ◽  
Fishery Management ◽  
Regional Scale ◽  
Single Species ◽  
Fishing Effort ◽  
Theoretical Concept ◽  
Maximum Sustainable Yield ◽  
Production Model ◽  
The Status ◽  
Long Time

The theory of maximum sustainable yield (MSY) underpins many fishery management regimes and is applied principally as a single species concept. Using a simple dynamic biomass production model we show that MSY can be identified from a long time series of multi-stock data at a regional scale in the presence of species interactions and environmental change. It suggests that MSY is robust and calculable in a multispecies environment, offering a realistic reference point for fishery management. Furthermore, the demonstration of the existence of MSY shows that it is more than a purely theoretical concept. There has been an improvement in the status of stocks in the Northeast Atlantic, but our analysis suggests further reductions in fishing effort would improve long-term yields.

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