نتایج جستجو برای: population change

تعداد نتایج: 1241284  

Journal: :international journal of health policy and management 2014
anthony j mcmichael

human-induced climate change, with such rapid and continuing global-scale warming, is historically unprecedented and signifies that human pressures on earth’s life-supporting natural systems now exceed the planet’s bio-geo-capacity. the risks from climate change to health and survival in populations are diverse, as are the social and political ramifications. although attributing observed health...

Journal: :Proceedings. Biological sciences 2005
John M Drake

Global circulation models predict and numerous observations confirm that anthropogenic climate change has altered high-frequency climate variability. However, it is not yet well understood how changing patterns of environmental variation will affect wildlife population dynamics and other ecological processes. Theory predicts that a population's long-run growth rate is diminished and the chance ...

Journal: :Environmental Change and Security Project report 2000
R E Benedick

Human populations have put pressure on their natural surroundings throughout history. Yet the world is now facing truly global environmental challenges and rapid population growth in the final half of the twentieth century is a critical component to understanding these phenomena. In his article, Ambassador Richard Benedick examines a host of population dynamics and their complex interlinkages...

2017
Lars Y. Pomara Benjamin Zuckerberg

Aim There is mounting concern that climate change will lead to the collapse of cyclic population dynamics, yet the influence of climate variability on population cycling remains poorly understood. We hypothesized that variability in survival and fecundity, driven by climate variability at different points in the life cycle, scales up from local populations to drive regional characteristics of p...

2006

The large and productive fishery of Lake Tanganyika is an important source of income and nutrition for the surrounding areas. This fishery, based primarily on pelagic clupeids (Kiswahili: dagaa), is very productive, and provides a readily available, nutritious, and inexpensive source of protein to the rapidly growing human populations in this area. The regional importance of the Lake Tanganyika...

2014
Yaoxian Huang Shiliang Wu Jed O. Kaplan

The occurrence of wildfires is very sensitive to fire meteorology, vegetation type and coverage. We investigate the potential impacts of global change (including changes in climate, land use/land cover, and population density) on wildfire frequencies over the period of 2000e2050. We account for the impacts associated with the changes in fire meteorology (such as temperature, precipitation, and ...

2000
A. J. Bennett

Thomas Malthus, in his ‘Essay on Population’ in 1798, argued that food production would not be able to keep pace with our capacity to produce. Contrary to this prediction there seems to be no evidence that our ability to produce food has been a lasting break on population growth. There are, however, several major areas of concern regarding environmental degradation associated with production ha...

Journal: :Ecology letters 2017
Manuel Massot Stéphane Legendre Pierre Fédérici Jean Clobert

The most documented response of organisms to climate warming is a change in the average timing of seasonal activities (phenology). Although we know that these average changes can differ among species and populations, we do not know whether climate warming impacts within-population variation in phenology. Using data from five study sites collected during a 13-year survey, we found that the incre...

Journal: :Science 2000
B Saether J Tufto S Engen K Jerstad O W Rostad J E Skâtan

Predicting the effects of an expected climatic change requires estimates and modeling of stochastic factors as well as density-dependent effects in the population dynamics. In a population of a small songbird, the dipper (Cinclus cinclus), environmental stochasticity and density dependence both influenced the population growth rate. About half of the environmental variance was explained by vari...

Journal: :Current Biology 2016
Michael Gross

Massive amounts of observation data recorded by amateurs are available for butterfl ies, allowing scientists to study their population dynamics and response to environmental threats. They report serious declines in many rarer species leading to an overall loss in biodiversity. As these declines refl ect the impacts of land use change, climate change and pesticide use, they also provide an alarm...

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