Science Unit One Chapter Two Cards

• A population is the number of reproducing organisms in a group or area
• e.g. human population is an estimated 7,300,000,000

• Exponential growth is growth where the increase in number is proportional to the number itself
• Can also mean the period before a population reaches its carrying capacity
• e.g. most population growth is exponential for a time (until carrying capacity is reached and the population is at an equilibrium)

• Factors which restrict the growth of a population
• e.g. amount of nutrients, amount of space, etc.

• The maximum number of a species which an ecosystem can support indefinitely
• When a population is at carrying capacity, it is at an equilibrium

• The resources used by an organism, as well as the limiting factors upon it and the biotic relationships it has with other organisms
• e.g. the brown bat's niche includes the insects it eats, the caves it nests in, and the birds it competes with for food

• An organism that eats another organism to get energy
• e.g. a wolf

• An organism that is eaten by another organism
• e.g. a moose, which is eaten by the wolf

• A biotic relationship between two organisms in which both organisms benefit
• e.g. coral and algae. The coral provide shelter for the algae, and the algae provide food for the coral.

• An organism which depends on close association with a larger host organism. The relationship benefits the parasite but often harms the host
• e.g brain worms and white-tailed deer

• A biotic relationship between two ore more organisms where said organisms are competing for some resource such as food, water, space, etc.
• e.g. brook and nine-spine stickleback fish. Competition for space has forced the brook stickleback to stick to the lower parts of the bodies of water they live in.

• Sustainable use is use of a resource which does not cause long-term depletion of said resource
• Such use allows the resource to supply future generations
• e.g. sustainable logging operations in which more trees are planted than are cut, and the speed of the logging allows the new trees to grow so the forest remains the same size or even grows

• The amount of time a population will take to double
• e.g. the human doubling time is ~60 years

• A measure of the impact of an individual or a population on the environment
• Includes energy consumption, land use, and waste production
• Is also a measure of the land and water that would be required to support the individual/population's lifestyle indefinitely
• e.g the US has the largest ecological footprint of any country

• A pattern which leads to decline of an ecosystem or population
• e.g. human use of the earth is highly likely to be unsustainable

• Use of resources at levels that can be continued indefinitely
• e.g. using resources at a rate that is equal to the rate at which they are replenished is sustainable

• Benefits experience by organisms which are provided by an ecosystem
• Examples are:
• Provision of resources
• Cycling of Nutrients
• Conversion of Carbon to Biomass
• Pollination of Crops/Vegetation
• Balance of Growth/Decomposition
• Provision of Beauty/Spirituality

• A process where an area which is not a desert becomes one
• e.g. when settlers came into Norfolk, they cut down a large number of trees, causing the land around that area to become a desert

A form of tourism provided by sustainable ecosystems which is sensitive to the health of said ecosystems