During which stage of the demographic transition do population growth rates increase?
During the first phase, the population growth rate rises as the death rate declines while the birth rate remains high. In the second phase, the growth rate declines (but remains positive) due to a decline in the birth rate.
Which of the following is the least viable strategy for ensuring adequate nutrition for a population of this size?
Doubling the area of arable land on a global basis is the LEAST viable strategy for ensuring adequate nutrition for a population of this size.
Which age structure diagram best depicts the ages in a population?
However, the use of a population pyramid is considered the best way to graphically illustrate the age and sex distribution of a given population. A population pyramid, using a paired bar chart-type graphic, shows the numbers or percentages of males and females in each age group.
Which of the following best explains why DDT has been found in penguin eggs in the Antarctic?
Which of the following best explains why DDT has been found in penguin eggs in the Antarctic? Chemicals used in one region of Earth can circulate in the biosphere and affect organisms in a distant region. The large number of penguins in Antarctica has resulted in a depletion of their preferred foods.
Why Has DDT been found in penguin eggs?
Adelies feed off tiny creatures called krill that live in melted glacier water, and DDT is transmitted up the food chain directly to the penguins. Warming on the peninsula means “we see more snow and more moisture and these (Adelie) eggs end up getting soaked and frozen,” Geisz said.
Where is desertification occurring most rapidly?
Africa is the continent most affected by desertification, and one of the most obvious natural borders on the landmass is the southern edge of the Sahara desert. The countries that lie on the edge of the Sahara are among the poorest in the world, and they are subject to periodic droughts that devastate their peoples.
Where is desertification occurring today?
Africa is the simple answer to the question: where is desertification happening? More specifically, desertification plays its largest role in the grasslands of East Africa, the Kalahari Desert and the Sahara Desert. These regions span over 65 percent of the land.
What change has occurred in the Sahel due to increasing population and overgrazing?
Between 1959-84, the population in the Sahel doubled so farmers have extended cultivation into marginal areas which are vulnerable to desertification. The livestock populations have also grown tremendously resulting in overgrazing and deforestation.
How is desertification linked to population growth quizlet?
Desertification is causing the droughts to began to get bigger and the people living in the Sahel to begin to be expanded into the desert due to them having no grass or water source. It is very hard for them to keep up with the growing population and not having enough resources.
Which are causes of desertification select three options quizlet?
What are the 3 main causes of desertification? 1) Over-cultivation. 2) Overgrazing. 3) Overuse of fuel wood….
- Over-cultivation means cattle are taken to graze where there is little vegetation cover.
- Dryland pastoral economies rely on grazing.
- Loss of traditional knowledge means cattle are not moved regularly.
Which is the greatest cause of extinction quizlet?
The primary cause of species extinctions is habitat destruction resulting from the expansion of human populations and activities.
What is the process of desertification and what causes it quizlet?
Desertification: the process of fertile land transforming into desert typically as a result of deforestation and dought, improper agricultural practices.
Which is a cause of decertification?
“Desertification is caused by a combination of factors that change over time and vary by location. These include indirect factors such as population pressure, socioeconomic and policy factors, and international trade as well as direct factors such as land use patterns and practices and climate-related processes.”
How is desertification caused by climate?
Both natural variability in climate and global warming can also affect rainfall patterns around the world, which can contribute to desertification. Rainfall has a cooling effect on the land surface, so a decline in rainfall can allow soils to dry out in the heat and become more prone to erosion.
What is the relationship between climate change and desertification?
The relationship between the two processes It is essential to recognise that desertification is essentially a man-made phenomenon which is exacerbated by climate change. This is because an increase in weather extremes such as droughts and heavy rains as a result of climate change will lead to further land degradation.