Results 251 to 260 of about 4,888,453 (287)

The spatial structure of populations

Journal of Animal Ecology, 1999
1. Studies of the spatio‐temporal dynamics and structure of populations have identified many categories of population type. However, recognized categories intergrade, making it difficult to assign empirical population systems to single categories. 2.
Chris D. Thomas, William E. Kunin
openaire   +1 more source

Tests of homogeneity for spatial populations

Statistics & Probability Letters, 2002
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +3 more sources

Spatial population dynamics

2019
Abstract This chapter considers populations structured in a different dimension: space. This begins by representing population dynamics with a spatial continuity equation (analogous to the M’Kendrick/von Foerster model for continuity in age or size). If organisms move at random, this motion can be approximated as diffusion.
Louis W. Botsford, J. Wilson White, Alan Hastings   +2 more
openaire   +1 more source

Spatial spread of a population

2014
After age structure, considered in Sect. 2.5 of Chap. 2, another source of heterogeneity in a population is the fact that individuals are located at different positions in the geographical region occupied by the population. Thus the description of the spatial structure of the population may become important if the habitat is not spatially homogeneous ...
Mimmo Iannelli, Andrea Pugliese
openaire   +1 more source

The Spatial Structure of Populations

2013
The area occupied by the free-ranging population is seen to have increased with numbers and hence density. For example, in Poland’s Bialowieza Forest, the area ranged over was three times as great in the 1990s as in the 1970s (when it was 130 km2), and six times as great by 2010. That period coincided with an increase in numbers from 200 to almost 500.
Małgorzata Krasińska, Zbigniew A. Krasiński   +1 more
openaire   +1 more source

Spatially implicit plankton population models: Transient spatial variability

Journal of Theoretical Biology, 2008
Ocean plankton models are useful tools for understanding and predicting the behaviour of planktonic ecosystems. However, when the regions represented by the model grid cells are not well mixed, the population dynamics of grid cell averages may differ from those of smaller scales (such as the laboratory scale). Here, the 'mean field approximation' fails
Wallhead, Philip J., Martin, Adrian P., Srokosz, Meric A.   +2 more
openaire   +4 more sources

On spatial population dynamics

Chaos, Solitons & Fractals, 2003
In economics, two-dimensional flow models have been studied for: 1) transport commodities, 2) interregional trade in extended markets, 3) expenditure diffusion, 4) migration, 5) population reproduction and redistribution. In this paper, the author studies the dynamics of population reproduction and spatial distribution in terms of a two-dimensional ...
openaire   +2 more sources

Spatial pattern and the mechanism of population regulation

Journal of Theoretical Biology, 1976
It has been suggested that the saturation density of many populations is adjusted to match environmental conditions by indirect controls rather than by direct physiological response to lack of some critical resource. This hypothesis is widely regarded as untestable since the observable effects of direct and indirect regulation have been held to be ...
Gurney, William, Nisbet, R.M.
openaire   +4 more sources

Spatially Balanced Sampling of Continuous Populations

Scandinavian Journal of Statistics, 2018
AbstractWhen sampling from a continuous population (or distribution), we often want a rather small sample due to some cost attached to processing the sample or to collecting information in the field. Moreover, a probability sample that allows for design‐based statistical inference is often desired.
Anton Grafström, Alina Matei
openaire   +1 more source

Spatial structure of populations

1999
Abstract Some species have practically continuous populations over large areas of suitable habitat; one example is the common shrew (Sorex araneus) in coniferous forests in Fennoscandia. Even in these cases, the environment is not quite as continuous as it might seem at first, and population density is likely to vary from one place to ...
openaire   +1 more source