scholarly journals Seasonal dynamics of a generalist and a specialist predator on a single prey

2021 ◽  
pp. 1-20
Author(s):  
Noah Bolohan ◽  
Victor LeBlanc ◽  
Frithjof Lutscher
Keyword(s):  
Seasonal Variation ◽  
Community Dynamics ◽  
Alternative Prey ◽  
Ecological Communities ◽  
Season Length ◽  
Simplified Models ◽  
Hunting Behaviour ◽  
Temporal Averaging ◽  
Invasion Analysis ◽  
Insight Into

In ecological communities, the behaviour of individuals and the interaction between species may change between seasons, yet this seasonal variation is often not represented explicitly in mathematical models. As global change is predicted to alter season length and other climatic aspects, such seasonal variation needs to be included in models in order to make reasonable predictions for community dynamics. The resulting mathematical descriptions are nonautonomous models with a large number of parameters, and are therefore challenging to analyze. We present a model for two predators and one prey, whereby one predator switches hunting behaviour to seasonally include alternative prey when available. We use a combination of temporal averaging and invasion analysis to derive simplified models and determine the behaviour of the system, in particular to gain insight into conditions under which the two predators can coexist in a changing climate. We compare our results with numerical simulations of the temporally varying model.

Large Surface Effect Ship Size Limits

2013 ◽  
Vol 29 (02) ◽  
pp. 84-91
Author(s):  
Stefanos Koullias ◽  
Santiago Balestrini Robinson ◽  
Dimitri N. Mavris
Keyword(s):  
Historical Data ◽  
Surface Effect ◽  
Advanced Materials ◽  
Complex Structures ◽  
First Principle ◽  
Simplified Models ◽  
Surface Effect Ship ◽  
Size Limits ◽  
Technology Level ◽  
Insight Into

The purpose of this study is to obtain insight into surface effect ship (SES) endurance without reliance on historical data as a function of geometry, displacement, and technology level. First-principle models of the resistance, structures, and propulsion system are developed and integrated to predict large SES endurance and to suggest the directions that future large SESs will take. It is found that large SESs are dominated by structural weight, which indicates the need for advanced materials and complex structures, and that advanced propulsion cycles can increase endurance by up to 33%. SES endurance is shown to be a nonlinear discontinuous function of geometry, displacement, and technology level that cannot be predicted by simplified models or assumptions.

scholarly journals Responsive Parametric Building Free Forms Determined by Their Elastically Transformed Steel Shell Roofs

Buildings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 46 ◽  
Author(s):  
Aleksandra Prokopska ◽  
Jacek Abramczyk
Keyword(s):  
Static Strength ◽  
Computer Applications ◽  
Steel Shell ◽  
Mutual Position ◽  
Simplified Models ◽  
Architectural Form ◽  
Parametric Description ◽  
Thin Walled ◽  
Interdisciplinary Study ◽  
Insight Into

The article concerns the unconventional architectural forms of buildings roofed with transformed shells made up of thin-walled steel fold sheets, and a parametric description of how they are shaped. Complicated deformations of flanges and webs, as well as the complex static–strength work of the folds in a shell roof, demand the creation of simplified models regarding the parameterization of such shells and their integration with the general forms of the buildings. To obtain favorable results, it was necessary to write computer applications because of both the complicated problems related to the significant limitations of the transformations, as well as the great possibilities of shaping shell roofs by means of directrices of almost free shape and mutual position. The developed procedures enable the prediction of shapes and states of all the folds in the designed shell. They take account of two basic conditions related to these restrictions, which guarantee that the folds encounter little resistance when matching their transformed forms to the roof directrices, and that their initial effort was as low as possible. The developed procedures required solving a number of issues in the fields of architecture, civil engineering, and structures, and are illustrated with an example of shaping one unconventional architectural form. The interdisciplinary study explains a new insight into shaping such forms.

scholarly journals Plankton community dynamics in a subtropical lagoonal system and related factors

2016 ◽  
Vol 88 (1) ◽  
pp. 249-267 ◽  
Author(s):  
LETÍCIA DONADEL ◽  
LUCIANA DE S. CARDOSO ◽  
LEZILDA C. TORGAN
Keyword(s):  
Seasonal Variation ◽  
National Park ◽  
Community Dynamics ◽  
Narrow Channel ◽  
Plankton Community ◽  
Related Factors ◽  
Temporary Connection ◽  
Salinity Changes ◽  
Spatial And Seasonal Variation ◽  
A Site

ABSTRACT Changes of the plankton community in a shallow, subtropical lagoonal system and its relation to environmental conditions were investigated during an annual cycle to provide information on its spatial and seasonal variation pattern. The study carried out at four sites (three in the Peixe lagoon and one in the Ruivo lagoon), which are located in the Lagoa do Peixe National Park, southern Brazil. The system has a temporary connection to the Atlantic Ocean by a narrow channel. The phytoplankton density was higher in the Peixe lagoon whereas the specific richness was higher in the Ruivo lagoon which is also a site with the lower salinity. The phytoplankton biomass near the channel showed seasonal variation with the highest value in fall and lowest in winter. Zooplankton richness was inversely correlated with salinity, and had the highest values in the Ruivo lagoon. Ordination analysis indicated seasonal and spatial patterns in plankton community in this lagoonal system, related to variation in salinity. In addition, the wind action and precipitation were important factors on the spatial and seasonal salinity changes in the lagoon with direct influence on the plankton community dynamics.

scholarly journals Erratum: A pyrosequencing insight into sprawling bacterial diversity and community dynamics in decaying deadwood logs of Fagus sylvatica and Picea abies

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Björn Hoppe ◽  
Dirk Krüger ◽  
Tiemo Kahl ◽  
Tobias Arnstadt ◽  
François Buscot ◽  
...  
Keyword(s):  
Picea Abies ◽  
Bacterial Diversity ◽  
Fagus Sylvatica ◽  
Community Dynamics ◽  
Insight Into

scholarly journals The macroecology of rapid evolutionary radiation

2011 ◽  
Vol 278 (1717) ◽  
pp. 2486-2494 ◽  
Author(s):  
Nicholas F. Parnell ◽  
J. Todd Streelman
Keyword(s):  
Adaptive Radiation ◽  
Species Interactions ◽  
Spatial Scales ◽  
Ecological Communities ◽  
Core Set ◽  
Evolutionary Radiation ◽  
Local Species ◽  
Entire Lake ◽  
Insight Into ◽  
Occurrence Of Species

A long-standing debate in ecology addresses whether community composition is the result of stochastic factors or assembly rules. Non-random, over-dispersed patterns of species co-occurrence have commonly been attributed to competition—a particularly important force in adaptive radiation. We thus examined the macroecology of the recently radiated cichlid rock-fish assemblage in Lake Malawi, Africa at a spectrum of increasingly fine spatial scales (entire lake to depth within rock-reef sites). Along this range of spatial scales, we observed a signal of community structure (decreased co-occurrence of species) at the largest and smallest scales, but not in between. Evidence suggests that the lakewide signature of structure is driven by extreme endemism and micro-allopatric speciation, while patterns of reduced co-occurrence with depth are indicative of species interactions. We identified a ‘core’ set of rock-reef species, found in combination throughout the lake, whose depth profiles exhibited replicated positive and negative correlation. Our results provide insight into how ecological communities may be structured differently at distinct spatial scales, re-emphasize the importance of local species interactions in community assembly, and further elucidate the processes shaping speciation in this model adaptive radiation.

scholarly journals Citizen-science data provides new insight into annual and seasonal variation in migration patterns

Ecosphere ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. art15 ◽  
Author(s):  
S. R. Supp ◽  
Frank A. La Sorte ◽  
Tina A. Cormier ◽  
Marisa C.W. Lim ◽  
Donald R. Powers ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Citizen Science ◽  
Science Data ◽  
Migration Patterns ◽  
Insight Into

scholarly journals Fish assemblage in a temperate estuary on the uruguayan coast: seasonal variation and environmental influence

2010 ◽  
Vol 58 (4) ◽  
pp. 299-314 ◽  
Author(s):  
Alicia Acuña Plavan ◽  
Cecilia Passadore ◽  
Luis Gimenez
Keyword(s):  
Seasonal Variation ◽  
Environmental Variables ◽  
Fish Community ◽  
Community Dynamics ◽  
Environmental Influence ◽  
Abundant Species ◽  
Multivariate Techniques ◽  
Micropogonias Furnieri ◽  
Definition Of ◽  
Paralichthys Orbignyanus

The seasonal dynamics of the fish community in the Pando estuary on the Uruguayan coast were studied in relation to environmental sampled monthly between May 2002 and June 2003. Individuals collected were identified, and classified into stages (juveniles, adults) and functional groups. Relationships between community dynamics and environmental variables were evaluated using uni- and multivariate techniques. Twenty-one species, mostly freshwater stragglers, estuarine and marine migrants were collected. The most abundant species were Micropogonias furnieri, Mugil platanus, Paralichthys orbignyanus and Brevoortia aurea and were represented by juveniles. The community varied seasonally with rapid shifts in spring and autumn associated with changes in temperature and salinity. Significant correlations between abundance and temperature may be related to the timing of life cycle events. In this estuary, the salinity appears to play a key role in the functional structure and in the use of the habitat by juveniles. This is relevant for the definition of estuaries as nursery areas: this definition is context-dependent and is determined by the salinity conditions.

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