Several predator species at risk of extinction in Southwestern Europe are dependent on the population density of European wild rabbits Oryctolagus cuniculus. Rabbit populations in the region, however, have recently undergone dramatic decreases in population density, which may be exacerbated by hunting. Current hunting policies set the autumn–winter season, just before the start of rabbit reprod...

OBJECTIVES We sought to examine characteristics of neighborhoods with changing older adult populations. METHODS We used 30 years (1980-2011) of data from four U.S. cities (n=392 neighborhoods; Birmingham, AL; Chicago, IL; Minneapolis, MN; Oakland, CA) and finite mixture modeling to identify trajectory classes: neighborhoods with "stable", declining, or increasing older adult populations (≥65 ...

Scholars and activists have hypothesized a connection between environmental change and out-migration. In this paper we test this hypothesis using data from Nepal. We operationalize environmental change in terms of declining land cover, rising times required to gather organic inputs, increasing population density, and perceived declines in agricultural productivity. In general, environmental cha...

Forest conversion for agriculture expansion is the most salient signature of human occupation of the earth's land surface. Although population growth and deforestation are significantly associated at the global and regional scales, evidence for population links to deforestation at micro-scales-where people are actually clearing0020forests-is scant. Much of the planet's forest elimination is pro...

For the majority of species, per capita growth rate correlates negatively with population density. Although the popular logistic equation for the growth of a single species incorporates this intraspecific competition, multi-trophic models often ignore self-limitation of the consumers. Instead, these models often assume that the predator-prey interactions are purely exploitative, employing simpl...

Economic impacts of invasive species worldwide are substantial. Management strategies have been incorporated in population models to assess the effectiveness of management for reducing density, with the implicit assumption that economic impact of the invasive species will also decline. The optimal management effort, however, is that which minimizes the sum of both the management and impact cost...

the objective of this study was to evaluate the effect of plant population and nitrogen rate on yield and yield components of corn (zea mays l, hybrid 704) in 2008 at mamasani region, fars province. the experiment was conducted as a factorial based on randomized complete block design with three replications. experimental factors was four plant population (75000, 90000,105000, and 130000 plant h...

The productivity enhancing capability of cities is widely noted. Yet, while urban innovative capacity is often assumed to arise due to the close proximity of diverse elements within cities, little empirical research has attempted to associate population density with urban innovation. Thus, this research investigates how the density of a specific class of workers, the " creative class " , affect...