The role of large-scale spatially explicit and small-scale localized processes on the population dynamics of cereal aphids

2005 ◽  
Vol 95 (6) ◽  
pp. 579-587 ◽  
Author(s):  
L. Winder ◽  
G.J.K. Griffiths ◽  
J.N. Perry ◽  
C.J. Alexander ◽  
J.M. Holland ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Spatial Pattern ◽  
Large Scale ◽  
Aphid Population ◽  
Small Scale ◽  
Spatially Explicit ◽  
Cereal Aphids ◽  
Field Scale ◽  
Crop Density ◽  
Activity Density

AbstractA field-scale study of the spatially explicit interaction between the carabid Poecilus cupreus Linnaeus, and two common aphid species (Sitobion avenae (Fabricius) and Metopolophium dirhodum (Walker)) in winter wheat was conducted. All three species showed considerable spatial pattern at the field scale. Activity-density of P. cupreus was an order of magnitude higher in the central part of the field compared to its periphery. Where P. cupreus activity-density was highest, S. avenae and M. dirhodum population peaks were delayed. Additionally, in the case of M. dirhodum, lower maximum counts were evident where P. cupreus activity-density was highest. An analysis of the movement of individual P. cupreus using release–recapture indicated that those beetles within the centre of the field exhibited reduced displacement, which may have caused the generation or maintenance of spatial pattern. Crop density was also measured throughout the field. Although crop density had no large-scale spatial pattern, its variability at the small-scale was consistent with an influence on aphid population dynamics. This study demonstrates empirically that both large-scale spatially explicit and small-scale localized processes influenced aphid population dynamics simultaneously.

Experimental small-scale grassland fragmentation alters aphid population dynamics

Oikos ◽  
2003 ◽  
Vol 100 (3) ◽  
pp. 581-591 ◽  
Author(s):  
Brigitte Braschler ◽  
Gerolf Lampel ◽  
Bruno Baur
Keyword(s):  
Population Dynamics ◽  
Aphid Population ◽  
Small Scale

Simulating Large-Scale Population Dynamics Using Small-Scale Data

2002 ◽  
pp. 275-301 ◽  
Author(s):  
Graham E. Forrester ◽  
Mark A. Steele ◽  
Richard R. Vance
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Small Scale ◽  
Scale Population ◽  
Scale Data

scholarly journals Small-scale spatial structure influences large-scale invasion rates

2019 ◽  
Author(s):  
Michael J. Plank ◽  
Matthew J. Simpson ◽  
Rachelle N. Binny
Keyword(s):  
Population Dynamics ◽  
Spatial Structure ◽  
Large Scale ◽  
Spatial Scales ◽  
Mean Field ◽  
Average Density ◽  
Small Scale ◽  
Local Interactions ◽  
Mean Field Model ◽  
Species Invasions

AbstractLocal interactions among individual members of a population can generate intricate small-scale spatial structure, which can strongly influence population dynamics. The two-way interplay between local interactions and population dynamics is well understood in the relatively simple case where the population occupies a fixed domain with a uniform average density. However, the situation where the average population density is spatially varying is less well understood. This situation includes ecologically important scenarios such as species invasions, range shifts, and moving population fronts. Here, we investigate the dynamics of the spatial stochastic logistic model in a scenario where an initially confined population subsequently invades new, previously unoccupied territory. This simple model combines density-independent proliferation with dispersal, and density-dependent mortality via competition with other members of the population. We show that, depending on the spatial scales of dispersal and competition, either a clustered or a regular spatial structure develops over time within the invading population. In the short-range dispersal case, the invasion speed is significantly lower than standard predictions of the mean-field model. We conclude that mean-field models, even when they account for non-local processes such as dispersal and competition, can give misleading predictions for the speed of a moving invasion front.

AN AGENT-BASED MODEL OF HUMAN DISPERSALS AT A GLOBAL SCALE

2013 ◽  
Vol 16 (04n05) ◽  
pp. 1350023 ◽  
Author(s):  
SIMONE CALLEGARI ◽  
JOHN DAVID WEISSMANN ◽  
NATALIE TKACHENKO ◽  
WESLEY P. PETERSEN ◽  
GEORGE LAKE ◽  
...  
Keyword(s):  
Population Dynamics ◽  
High Performance ◽  
Large Scale ◽  
Global Scale ◽  
Small Scale ◽  
Emergent Properties ◽  
Agent Based ◽  
Human Dispersal ◽  
Model Hierarchy ◽  
Empirical Context

In this paper, we report on the theoretical foundations, empirical context and technical implementation of an agent-based modeling (ABM) framework, that uses a high-performance computing (HPC) approach to investigate human population dynamics on a global scale, and on evolutionary time scales. The ABM-HPC framework provides an in silico testbed to explore how short-term/small-scale patterns of individual human behavior and long-term/large-scale patterns of environmental change act together to influence human dispersal, survival and extinction scenarios. These topics are currently at the center of the Neanderthal debate, i.e., the question why Neanderthals died out during the Late Pleistocene, while modern humans dispersed over the entire globe. To tackle this and similar questions, simulations typically adopt one of two opposing approaches, top-down (equation-based) and bottom-up (agent-based) models of population dynamics. We propose HPC technology as an essential computational tool to bridge the gap between these approaches. Using the numerical simulation of worldwide human dispersals as an example, we show that integrating different levels of model hierarchy into an ABM-HPC simulation framework provides new insights into emergent properties of the model, and into the potential and limitations of agent-based versus continuum models.

scholarly journals Influence Mechanism of Production-Living-Ecological Space Changes in the Urbanization Process of Guangdong Province, China

Land ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1357
Author(s):  
Yingxian Deng ◽  
Ren Yang
Keyword(s):  
Spatial Pattern ◽  
Pearl River Delta ◽  
Large Scale ◽  
Guangdong Province ◽  
River Delta ◽  
Pearl River ◽  
Small Scale ◽  
The Pearl River Delta ◽  
The Pearl River ◽  
Point Type

Referencing the land use classification system of the “production-living-ecological” space and using 1 km × 1 km grids, this study examines the spatial pattern changes of “production-living-ecological” space in Guangdong Province, China, from 1990 to 2017. In the study, a multiple linear regression analysis model was constructed to explore the influencing factors and attribution mechanism of the changes. The results showed that between 1990 and 2017, the production spaces were mainly distributed in the Pearl River Delta and other coastal areas, showing a slight expansion trend (1). The expansion of production spaces mainly gathered in the Pearl River Delta, while the reduction was characterized by point-type dispersed. Living spaces were mainly distributed in the Pearl River Delta, the Shantou–Shanwei–Chaozhou–Jieyang urban agglomeration, the Zhanjiang-Maoming–Yangjiang urban agglomeration, and other rapidly growing urbanized areas. They showed a spatial pattern of “large scale agglomeration and small scale dispersion” with a trend towards expansion. Living spaces in urban agglomerations such as the Pearl River Delta showed a large-scale expansion from the core to the peripheral area, while expansion in other areas was small-scale and point-type. The reduction of living spaces was point-type dispersed. The ecological spaces were mainly distributed in mountainous and hilly areas in eastern, western, and northern Guangdong and showed a “regional agglomeration and partially fragmented” spatial pattern. Ecological spaces in urban agglomerations showed large-scale and regional reductions, while reductions in other areas were small-scale and point-type. Ecological space expansions were point-type dispersed. Human, natural, and especially land-use type factors drove the changes of Guangdong’s production-living-ecological spaces (2). The changes of the production-living-ecological space pattern resulted from the interaction between human society, nature, and politics (3).

FIELD-SCALE ROLES OF DENSITY, TEMPERATURE, NITROGEN, AND PREDATION ON APHID POPULATION DYNAMICS

Ecology ◽  
2008 ◽  
Vol 89 (2) ◽  
pp. 532-541 ◽  
Author(s):  
Perry de Valpine ◽  
Jay A. Rosenheim
Keyword(s):  
Population Dynamics ◽  
Aphid Population ◽  
Field Scale

Small-Scale Science to Large-Scale Profession

2000 ◽  
Vol 45 (4) ◽  
pp. 396-398
Author(s):  
Roger Smith
Keyword(s):  
Large Scale ◽  
Small Scale

Development of Physics Learning Module Based on Guided Inquiry with Light Wave Material in Class XI of Senior High School

2020 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Evi Rahmawati ◽  
Irnin Agustina Dwi Astuti ◽  
N Nurhayati
Keyword(s):  
Large Scale ◽  
Learning Strategy ◽  
Student Response ◽  
Average Score ◽  
Small Scale ◽  
Design Development ◽  
Teacher Response ◽  
Student Responses ◽  
Analysis Design ◽  
Scientific Skills

IPA Integrated is a place for students to study themselves and the surrounding environment applied in daily life. Integrated IPA Learning provides a direct experience to students through the use and development of scientific skills and attitudes. The importance of integrated IPA requires to pack learning well, integrated IPA integration with the preparation of modules combined with learning strategy can maximize the learning process in school. In SMP 209 Jakarta, the value of the integrated IPA is obtained from 34 students there are 10 students completed and 24 students are not complete because they get the value below the KKM of 68. This research is a development study with the development model of ADDIE (Analysis, Design, Development, Implementation, and Evaluation). The use of KPS-based integrated IPA modules (Science Process sSkills) on the theme of rainbow phenomenon obtained by media expert validation results with an average score of 84.38%, average material expert 82.18%, average linguist 75.37%. So the average of all aspects obtained by 80.55% is worth using and tested to students. The results of the teacher response obtained 88.69% value with excellent criteria. Student responses on a small scale acquired an average score of 85.19% with highly agreed criteria and on the large-scale student response gained a yield of 86.44% with very agreed criteria. So the module can be concluded receiving a good response by the teacher and students.

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