1. Changes in Ecosystems
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2. How ecosystems change
Seasonal changes impact food availability, temperature, and density of living things.
Long-term changing of the climate causes shifts in biodiversity
Biodiversity - the variety of life in the world or in a particular habitat or ecosystem
Humans can impact an ecosystem by using its resources.

3. Seasonal Changes
Availability of food (some plants only grow during spring or summer)
Migrations (animals move between ecosystems in the spring and fall)
Hibernations (some animals hibernate during winter months)
Mating/calving seasons (some animals only mate or have babies during certain times of year)

4. Climate Change
Climate is the long-term weather conditions of an ecosystem or area.
Changes to climate include long- term changes to temperature range during each season, long- term changes to the amount and type of precipitation, long-term changes to the wind or current patterns.
Climate change can impact what living things can and can not live within an area.

5. Human Impacts
Humans impact natural ecosystem through the use of resources.
Resources can be classified as either renewable or non- renewable.
Renewable resources – a resource that can be renewed or replenished as quickly as it is used (sunlight, for example)
Non-renewable resources – a resource that can not be renewed or replenished as quickly as it is used (fossil fuels, for example)

6. Point and Non-Point Pollution
Humans also add pollution to natural environments.
Point source pollution - any single identifiable source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack
Non-point source pollution – Pollution caused by rainfall or snowmelt moving over and through the ground, picking up picks up and carries away natural and human- made pollutants

7. Ecological Succession
Ecological succession is the process of major change among the species present in an ecosystem over time. There are two types:
Primary succession – when living things first populate a new ecosystem (after a new island forms, for example)
Secondary succession – when living things return to an area after a disaster (life returns to an area after a volcanic eruption or fire)