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Population geographyis the study of the distribution, composition, migration, and growth of human populations in relation to the geographic characteristics of specific area. It focuses on how populations are distributed across space, the factors influencing these distributions, and the implications for resources, environment, and societal ...
Pollution by heavy metals decreases the soil organic matter composition resulting in a decline in soil nutrients which then leads to a decline in the growth of plants or even death. [198] Besides creating environmental damage, the contamination resulting from leakage of chemicals also affect the health of the local population. [199]
A population ecology concept is r/K selection theory, one of the first predictive models in ecology used to explain life-history evolution. The premise behind the r/K selection model is that natural selection pressures change according to population density. For example, when an island is first colonized, density of individuals is low.
Population pressure, a term summarizing the stress brought about by an excessive population density and its consequences, is used both in conjunction with human overpopulation and with other animal populations that suffer from too many individuals per area (or volume in the case of aquatic organisms).
Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans , but sometimes to other living organisms too. It is a key geographical term.
Most of the exponential human population growth worldwide is occurring in or close to biodiversity hotspots. [6] This may explain why human population density accounts for 87.9% of the variation in numbers of threatened species across 114 countries, providing indisputable evidence that people play the largest role in decreasing biodiversity. [18]
A demographic structure of a population is how populations are often quantified. The total number of individuals in a population is defined as a population size, and how dense these individuals are is defined as population density. There is also a population's geographic range, which has limits that a species can tolerate (such as temperature).
Some climate change effects: wildfire caused by heat and dryness, bleached coral caused by ocean acidification and heating, environmental migration caused by desertification, and coastal flooding caused by storms and sea level rise. Effects of climate change are well documented and growing for Earth's natural environment and human societies. Changes to the climate system include an overall ...