نتایج جستجو برای: population growth rate
تعداد نتایج: 2249231 فیلتر نتایج به سال:
A matrix population model is a convenient tool for summarizing per capita survival and reproduction rates (collectively vital rates) of a population and can be used for calculating an asymptotic finite population growth rate (λ) and generation time. These two pieces of information can be used for determining the status of a threatened species. The use of stage-structured population models has i...
1. Researchers often use the spatial distribution of insect offspring as a measure of adult oviposition preferences, and then make conclusions about the consequences of these preferences for population growth and the relationship between life-history traits (e.g. oviposition preference and offspring performance). However, several processes other than oviposition preference can generate spatial ...
It is often presumed that infertility is not a problem in resource-poor areas where fertility rates are high. This is challenged by consistent evidence that the consequences of childlessness are very severe in low-income countries, particularly for women. In these settings, childless women are frequently stigmatized, isolated, ostracized, disinherited and neglected by the family and local commu...
Fertility rates in other developing regions have continuously declined, except subSaharan Africa, with the fastest population growth (5.2 children per woman – WDI, 2004); this is so, despite high mortality levels due to AIDS pandemics, decline in per capita income and the relatively high contraceptive availability and knowledge. This pattern of events has consequently, reduced productivity and ...
Background Studies directed at understanding the demography and population dynamics of corals are relatively scarce. This limits our understanding of both the dynamics of coral populations and our capacity to develop management and conservation initiatives directed at conserving such ecosystems. Methods From 2012 to 2014, we collected data on the growth, survival, and recruitment rates of two...
In the context of ongoing world population growth, no permanent growth in materials consumption can be sustained into the future. A sustainable future requires that the world's population stabilize. The author considers the possible coupling of the annual energy use per capita and the population growth rate for each region, and the consequences of such a connection if the world's population i...
Across Europe, rapid population declines are ongoing in many Afro-Palaearctic migratory bird species, but the development of appropriate conservation actions across such large migratory ranges is severely constrained by lack of understanding of the demographic drivers of these declines. By constructing regional integrated population models (IPMs) for one of the suite of migratory species that i...
Niger—with the world’s fastest growing population, its highest total fertility rate (TFR), a small and diminishing amount of arable land, low annual rainfall, a high level of malnutrition, extremely low levels of education, gross gender inequities and an uncertain future in the face of climate change—is the most extreme example of a catastrophe that is likely to overtake the Sahel. The policies...
Connecting isolated patches of habitat in fragmented landscapes with corridors is a popular conservation strategy. This strategy is also controversial in large part because of uncertainty about what characteristics of a species and its environment promote corridor use. In this article we address the question, For what types of species will populations benefit from corridors? We asked this quest...
Human consumption is depleting the Earth's natural resources and impairing the capacity of life-supporting ecosystems. Humans have changed ecosystems more rapidly and extensively over the past 50 years than during any other period, primarily to meet increasing demands for food, fresh water, timber, fibre and fuel. Such consumption, together with world population increasing from 2.6 billion in 1...
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