Population, Carrying Capacity, Limiting Factors, & Ecological footprint
Key Definitions • Population • is a summary of all the organisms of the same group or species, who live in the same geographical area, and have the capability of interbreeding • Carrying capacity • The maximum population an environment can sustain • Limiting factors • Factors that limit the growth and development of a species or process
Population • There are three important characteristics of population: geographic distribution, density, and growth rate. • These things will determine how successful your population will be.
Population Increase http://www.youtube.com/watch?v=4BbkQiQyaYc Population Crisis https://www.youtube.com/watch?v=8q0uKxiw4Tk Population Growth → • The growth rate of a population depends on demographic transitions and age structure • Add to population: birth and moving into the area (immigration) • Reduce population: death and moving away from the area (emmigration) • Stable populations have an even spread of ages throughout the population • The human population is currently exponentially increasing in size, which is causing a higher demand of resources • Currently, third world and developing countries are adding the most members to the population
Population Growth based on population changes from 2010-2015 Growing Africa Middle East Constant The US Europe South America Shrinking Japan Eastern Europe
Carrying Capacity→ • A population cannot exceed the carrying capacity of an area due to limits in supplies. • The carrying capacity: • is tied to resource availability: food, land, water, and shelter • can vary from year to year. • If you exceed the carrying capacity of your environment you introduce problems such as disease
Limiting Factors → • Populations are impacted by limiting factors • There are two types of limiting factors: 1. Density-independent factors • This factor is not influenced by population size • Unusual weather, natural disasters, seasonal cycles, and human activities 2. Density-dependent factors • This factor depends on the population size → have a greater impact when the ecosystem is densely populated • Types: Competition, Predation, Parasitism, Disease, and crowding
Ecological footprint → • is a measure of the human demand on resources such as water, land, and food • Footprints vary from person to person and region to region • Areas that are industrialized like the US have a larger footprint than other areas because we have a higher demand of resources