Communities and Biomes

1. Communities and Biomes • AHSGE • Standard I objective 1 • Analyze the methods of science used to identify and solve problems • Standard VI Objective 1 • Demonstrate an understanding of factors that affect the dynamic equilibrium of populations and ecosystems • AL COS • 7, 39, 40

2. Communities • A community is an interacting population of different species. • Limiting factor- any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms. • Ex. Food availability, predators, temperature • Tolerance- the ability of an organism to withstand changes in abiotic and biotic factors in an ecosystem. • Optimal conditions usually fall midway between an organism’s limits of tolerance • Age, physical condition, and stage in its life cycle may all influence an organism’s limits of tolerance • The range of factors under which an organism functions and survives are its limits of tolerance

3. Succession is the replacement of one community by another as environmental conditions change. • Primary succession- the colonization of new sites by communities of organisms. • Pioneer organisms are the first species in an area. • Ex. Lichen • Climax community- a stable, mature community that undergoes little or no change in species. • Characterized by complex food webs, many different species of organisms, and little or no succession. • Usually the stable result of succession. • Secondary succession- the sequence of community changes that takes place after a community is disrupted by natural disasters or human actions. • Ex. of possible causes-- Fires, natural disasters, and human intervention • Ex. Uncut lawn—meadow—forest

4. Biomes • Ecosystems that have similar kinds of climax communities that are grouped into a broader category of organization are called biomes. • A biome is a large group of ecosystems that share the same type of climax community • Two main types of biomes: • Terrestrial biomes- biomes located on land • Ex. Tundra, Taiga, Desert, Grassland, Temperate Forest, Tropical Rain Forest Terrestrial movie

5. Aquatic biomes- biomes located in oceans, lakes, streams, ponds, or other bodies of water. Ex. Marine and freshwater • Marine biomes: • Contain the largest amount of biomass, or living material, of any biome on earth. • The portion of the marine biome that is shallow enough for sunlight to penetrate is called the photic zone. • Microscopic organisms that float in the sunlit regions of the ocean are plankton. • Form the base of all food chains • Most producers here • Deeper water that never receives sunlight makes up the aphotic zone. • An estuary is a coastal body of water, partially surrounded by land, in which freshwater and saltwater mix. • Saltmarsh ecosystems are usually associated with estuaries. • Tides are caused by the gravitational pull of the sun and moon. • The portion of the shoreline that is affected by the changing of tides is called the intertidal zone. • Why no producers? • Limited by waves crashing against the shore

6. Freshwater Biomes • There are two abiotic factors that limits life in deep lakes: • Temperature • Light • Concentric bands of different plant species are characteristic of freshwater biomes.

7. Tundra • Temperature is a major limiting factor of the tundra biome. • Underneath the topsoil is a layer of permanently frozen ground called permafrost.

8. Animals of the tundra Artic Fox PolarBear Oxen

9. Taiga • Northern coniferous forest. • Long severe winters and short, mild summers. • Permafrost is absent. • Stretches across Canada, Northern Europe, and Asia.

10. Animals of the Taiga Wolverine Bobcat Caribou Black Bear

11. Desert • The driest biome. • An arid region with sparse to almost nonexistent plant life. • Usually gets less than 25 cm of precipitation annually. • Driest place in the world: • Atacama desert in Chile • Annual rainfall: None • Ex of animals: small herbivores that remain under cover during the heat of the day: kangaroo rat, coyotes, owls, roadrunners, snakes, lizards • Cacti are succulent plants with thorns that are common in desert biomes Desert Movie

12. Animals of the Desert Kangaroo rat Roadrunner

13. Grassland Zebras Prairie dogs • Large communities covered with grasses and similar small plants. • Occupies more area than any other terrestrial biome. • Most grasslands are populated by herds of grazing animals. • Ex. of animals: Bison/Buffalo, prairie dogs, foxes, ferrets, insects, birds, reptiles, zebra, elephant

14. Temperate Forest • Dominated by broad-leaved hardwood trees that loose their foliage annually—Deciduous trees • Ex. of animals: Squirrels, mice, rabbits, deer, bears.

15. Tropical Rain Forest • Home to more species of organisms than any other place on Earth. • Warm temperatures(because it is near the equator), wet weather(because wind patterns drop a lot of precipitation on them), and lush plant growth. • Decomposition occurs too quickly for humus to form. • Tropical rain forest and tundra biomes are both characterized by a thin layer of nutrient-poor topsoil that can support only shallow-rooted plants Rainforest Movie

16. Animals of the rain forest

17. Why do tropical rain forests contain so many species? • Their location near the equator prevented the land from being covered by ice during the last ice age. This allowed the communities of species to have more time to evolve. • The warm weather gives tropical rain forest plants year-round growing conditions. Which creates a greater food supply which can support larger numbers of organisms. • Tropical rain forests provide a multitude of possible habitats for diverse organisms.

18. Teacher Activities/Labs • Adaptations of Animals in Biomes • Make It a Habitat • Forest fires