A fundamental characteristic of any biological invasion is the speed at which the geographic range of the population expands. This invasion speed is determined by both population growth and dispersal. We construct a discrete-time model for biological invasions that couples matrix population models (for population growth) with integrodifference equations (for dispersal). This model captures the ...

This paper shows, in a two-sector Malthusian model of endogenous population growth, that output per capita, population density, and industrialization depend upon the labor intensity of agricultural production. Because the diminishing returns to labor are less pronounced, high labor intensity (as in rice production) leads not only to a larger population density but also to lower output per capit...

T he Netherlands is a small country in Western Europe, located on the North Sea coastal area at the mouth of the rivers Rhine and Meuse, bordering Belgium and Germany. The territory of the Netherlands covers 41,574 km of which 7,636 km are water. About one-quarter of the country, especially the western part where land has been reclaimed from the sea since the 16th century, actually lies below s...

This paper extends the Lotka system of stable population equations to any population. The authors present this new general system and describe its duality with the recent Preston-Coale system. They derive these results by considering the calculus of change on the surface of population density defined over age and time. They show that analysis of this Lexis surface leads to all the known fund...

Dispersal is a context-dependent adaptive trait. Different dispersal strategies arise as species need to optimize their fitness in the ever changing quality of habitats further imposed by abiotic and biotic factors. This work reviews the spread of populations under different dispersal strategies. Namely, we address the spread of a population when dispersal is driven by habitat fragmentations, d...

1. As plant invasions pose one of the greatest threats to biodiversity, it is critical to improve both our understanding of invasiveness and strategies for control. Much research into plant invasions and their management, including biological control, assumes strong demographic effects by natural enemies, including herbivores. However, the importance of natural enemies in the regulation of plan...

African cities face immense challenges over the coming decades. As countries urbanize, African cities must maintain service provision for rapidly increasing populations, yet with limited resources. In particular, urban food systems must be able to cope with regional food shortages and catalyze (or at least enable) the distribution of food from diverse sources in order to ensure that the cost of...

In this paper theory from population biology is combined with stochastic differential equations. The aim is to compare previously studied deterministic population models with corresponding stochastic population models. As an illustrative example the models are applied to a classical dataset (Gause, 1934). The first half of the paper gives a brief review of the theoretical background needed in o...

We study a population model in which there are two species, one of which has a juvenile and adult life stage. The adults of the first species prey on the second species, which in turn preys on the juveniles of the first. One version of the model represents systems where neither species can survive on its own, although we find that both can survive through mutual predation. To avoid extinction, ...

In this work, we analyzed the impact of interventions on populations which exhibit unimodal dynamics. The six landmarks that characterize the “shape” of the unimodal reproduction curve   f x of the difference equation,   1 n n X f X   , are defined and used in order to examine and determine the behavior of dynamics of populations. By using the Li-Yorke criterion for determination of chaos...