Ecosystems
Adaptations
Structural adaptations (physical features):
Camouflage: animals like chameleons blend in with their environment so it is harder for predators to catch them
Fur: animals living in cold climates have thick fur coats to help them keep warm
Behavioral adaptations (activities):
Nocturnal animals: animals like mice only come out at night so that they can avoid predators that hunt during the day
Migration: animals make long seasonal trips to different regions, which can help them find more food, move to places with a better climate, or for other reasons
Populations, Communities, and Ecosystems
Population: all the organisms of the same species that live in the same place at the same time
A group of frogs living in a pond
Community: multiple populations that live in the same place at the same time
Groups of fish, frogs, ducks, and lily pads that live in that pond
Ecosystem: a community and the nonliving factors in its environment
All the organisms in the pond as well as non-living things such as water and rocks
Food Webs
A food web shows the connections between organisms in an ecosystem and shows what eats what.
Levels of a food web:
Producers: take in the sun’s energy and make their own food (examples: grass, trees, flowers, algae)
Consumers
Primary consumers: herbivores that eat producers for energy (examples: rabbits, cows, deer)
Secondary consumers: carnivores that eat primary consumers (examples: lions, tigers)
Tertiary consumers eat secondary consumers and so on
Animals can belong to multiple levels of a food web: omnivores eat both producers (plants) and consumers (animals) (examples: foxes, bears)
Decomposers
An organism that breaks down dead bodies of organisms at every level (examples: mushrooms, bacteria)
Habitats and Niches
Habitat: place where an organism lives that provides food, water, shelter, and space to the organism
Niche: the function that an organism performs in the food web of that community, as well as everything the organism does and needs in its environment
No two types of organisms occupy exactly the same niche in a community.
During its life cycle, an organism’s role in the community (niche) may change.
Tadpoles and adult frogs have different interactions with their environment
Human Impacts
Humans can have major impacts on ecosystems, positive or negative.
Positive impacts:
Protecting endangered species: conserving species keeps ecosystems intact
Cleaning oceans and rivers: by doing this, we are providing a clean habitat for organisms
Negative impacts:
Deforestation: humans cut down trees, which disrupts ecosystems
Pollution: humans release chemicals into the air and water, which harms organisms
Global warming: the new hotter temperatures affect the balance of ecosystems
