Chapter 12: Interactions Within Ecosystems 12.1: Groups of living things interact within ecosystems 12.2: Organisms can interact in different ways 12.3: Ecosystems are always changing

How can you estimate population in an area. Is this accurate How can you estimate population in an area? Is this accurate? Limitations?

Organisms occupy specific living areas Living things in an ecosystem depend on their environment to meet their needs Area characteristics help determine the types of living things you will find in that area Recall: Species: organisms grouped according to shared characteristics Same species: can mate and reproduce

Population Vibrio Tubiashii A group of organisms of the same species that live in a particular area People in a city/town Group of plants/animals/bacteria/fungi/etc.

Habitats and Niches Habitat: physical location where plants and animals live Ex: island, woods, etc Specific physical characteristics describes them Precipitation, temperature range, soil quality Filled with many different species Characteristics determine plant life Which determines the other (ex: animal) life there Interaction between species leads to energy and matter flow through the ecosystem Galapagos: cacti captures sunlight, (stores) water, and CO2  produces O2 and food for the iguana (eats leaves) Each has a role to play in the habitat = “niche”

Niches Habitat – specific characteristics control what species will be found

Communities Ex: school- has students, teachers, etc Work together to help each other Occupy the same space “Biological community”: group of populations that live in a particular area and interact

The environment can be organized into five levels Biome general climate and types of plants found in similar places on the planet Ecosystem a biome contains many ecosystem Living and nonliving factors form a stable system Only organisms and their local environment Community the living components Plants, animals, and other organisms interact Population group of organisms of the same species living in the same area Organism A single individual animal, plant, fungus, etc

(Organism)

Patterns exist in populations Patterns in living space Individuals may be crowded together, spread far apart, or live in small groups Ex: Creosote bushes in California’s Mojave desert Evenly spaced because the roots of each bush release a toxin preventing the roots of other bushes from growing Enough spacing for animal food supply and raise young Closely compacted: group safety

Patterns exist in populations Patterns in Time: Numbers of individuals may rise and fall, depending on season or other condition In spring and throughout summer, a queen wasp lays eggs Population grows throughout the summer and fall In winter, all wasps die except the queen Some birds fly south for the winter

Cicadas- every 17 years adults lay eggs for the next generation Young hatch and grow underground over the next 17 years cicadas video video2