Chapter 2- Populations and Sustainable Ecosystems Glossary Terms

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Chapter 2- Populations and Sustainable Ecosystems Glossary Terms
2015-09-29 22:20:08
glossary terms

Definition and explanation of each term in chapter 2. This will also be used for tests and the final exam.
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  1. Population
    • All the individuals of a species that live in the same area at the same time 
    • There are many factors that can influence population growth; if there are unlimited resources, the population will tend to increase and if there are limited resources, the population would tend to decrease   
    • A growth curve can be used to to show the increase/decrease in population; broken down into 3 parts, which is the log phase (point where population increases), exponential growth and carrying capacity (refer to definition 2 and 4 for the meanings)
    • A typical growth curve

  2. Exponential Growth
    • This growth of a population usually occurs under certain conditions like introduction to a new habitat with unlimited resources and for a short period of time
    • It produces a J-like curve when the population is graphed over time 
    • Exponential growth can be restricted from limiting factors
    • Cannot be sustained in nature and this growth does not last long because no ecosystem has a unlimited supply of resources for oganisms (limiting factors)
    • A growth curve showing where the exponential growth is located

  3. Limiting Factors
    • A factor that limits the growth, distribution or amount of population in an ecosystem
    • Prevents exponential growth 
    • When the population increases, the fewer resources there are for each organism, limiting the population and restricting it from growing any larger
    • The factors can both be abiotic or biotic
    • Limiting factors could be food, water, temperature, light and shelter
    • For example, there are 30 flying squirrels and there is enough water and space for 50 of them but there is a limiting factor on food which is preventing the population from growing
  4. Carrying Capacity
    • The size of a population that can be supported indefinitely by the resources and conditions of a given ecosystem 
    • Population size is at a steady rate (equilibrium) or in balance at carrying capacity 
    • If a resource is used that is going over the ecosystem's carrying capacity, then the population would tend to decrease but it will drop to a new carrying capacity 
    • If the resources used are below the carrying capacity, then the population would tend to increase as well as the carrying capacity
    • Carrying capacity

  5. Ecological Niche
  6. Predator
    • It is an organism that kills and consumes other organisms for survival (prey)
    • Predator influence prey in population size, so there is the bottom-up population regulation, which is when a species at a lower trophic level decreases due to lack of resources causing declines in the number of animals in higher trophic levels 
    • There is also the top-down population regulation which is when a prey species increases also causing an increase of predators at higher trophic levels and then at some point, there will be a decrease in prey and that would result in a decrease of predator species; this causes a repeating cycle between the two  
    • Examples of predators would be lions, sharks, humans and owls (most predators are animals)
  7. Prey
    • Is the organism the predator kills and consumes for food
    • Influence the amount of predators there are in the food chain (refer to predator definition for both sets of population regulations)
    • Usually at the bottom of the food chain and most prey are herbivores 
    • Examples would be a moose, rabbit, deer, insects and the snowshoe hare
  8. Mutualism
    • Is symbiosis in which both of the species benefit from the relationship
    • For example the oxpecker and the zebra because the bird eats ticks off the zebra and they get food from that OR a bee and a flower because the bees pollinate the flowers and the bees get the nectar to make honey
  9. Parasite
    • An organism who's niche is dependent on a close association with a larger host organism 
    • For example the deer and the brain worm, the worm lays eggs in the deer's brain which travels to the lungs where they hatch and after they are excreted, the deer eats a slug which contains the worm
  10. Competition
    • Is when two or more organisms compete for the same resources in the same area and time 
    • Can also limit population size; the more energy used for competition, the less time for growth and reproduction
    • For example, sparrows because as they compete for food due to a large population, the average number of eggs laid are decreased 
    • May also influence an organisms ecological niche 
    • For example, cheetahs and lions compete because they have the same prey and the amount of that food is limited for them so they fight for it
  11. Sustainable Use
    • Use that does not lead to long term depletion of a resource or affect the diversity of the ecosystem from which the resource is obtained 
    • Whether it is water or an entire ecosystem, it allows the resource to meet the needs of present and future generations
    • If humans don't use resources in a sustainable way, our niche may shrink again over time
  12. Doubling Time
    Period of time required for a population to double in size
  13. Ecological Footprint
    • A measure of the impact of an individual or population on the environment in terms of energy consumption, land use, and waste production
    • Reflects the behavior of individuals and the communities they live in
    • A way to reduce ecological footprint is to consume fewer resources or using existing resources more efficiently through technological innovation, energy efficiency and recycling
  14. Unsustainable
    • A pattern of activity that leads to a decline in the function of an ecosystem 
    • There aren't many resources for present and future generations 
    • The ecosystem is not able to sustain 
    • Things are mostly unsustainable because of the increase in population since more resources have to be used and more energy has to be consumed to survive
  15. Sustainability
    • The use of Earth's resources such as land and water at levels that can continue forever 
    • Use them at a rate that the Earth can renew them
  16. Ecosystem Services
    • The benefits experienced by organisms like humans, that are provided by sustainable ecosystems 
    • They provide provision of food and clean water, cycling of nutrients, conversion of atmospheric carbon into biomass, pollination of crops and natural vegetation, the balance of processes such as growth and decomposition and the provision of beauty and spirituality  
    • Allow ecosystems to function which is important for sustainability
    • Examples could be a forest and insects
  17. Desertification
    • The change of non-desert land into a desert
    • Reasons could be from climate change, unsustainable farming or water use
    • Loses its body of water, vegetation and wildlife
    • Some areas in Ontario have desert land because trees where cut down for lumber and all the land was cleared for agriculture 
    • Some ways to prevent desertification is to plant more trees, farmers can sustain more of their land
  18. Ecotourism
    A form of tourism that is sensitive to the health of an ecosystem and involves recreational activities provided by sustainable ecosystems