Chapter 3 Communities and Biomes Part 1

Ecosystem: interactions among populations in a community Consists of: A community of organisms The soil, water, and weather Energy

Succession: changes over time Primary succession – gradual growth of an ecosystem over a long period of time. Example: Hawaii. Rock -> Lichen -> moss -> grass -> shrub -> tree -> vines

Succession: changes over time Pioneer species – first species in an area

Succession: changes over time Climax community – shows little or no change over time Secondary succession (previously supported vegetation) – sequence of life after natural disasters (examples: Forest fires, glaciers, avalanches, flood, hurricane, tsunami, tornadoes). 1988 forest fire in Yellowstone Nat’l Park

Chapters 3-4 Communities and Biomes / Population Part 2

Biome - a major ecosystem that shares the same type of climate and has similar life forms. Salt water Freshwater Estuary (mix of salt and fresh water) Terrestrial (dry land)

CLIMATOGRAM - Measures two things: Average Temperature Average Precipitation

Tundra (Alpine and Arctic) Permafrost - permanently frozen ground Plants - short roots; fast growing; perennials. Animals have thick fur / body fat / coloration.

Taiga / Coniferous Forest Conifers - cone-bearing trees / bending branches / needles as leaves. Animals also have thick fur / body fat.

Temperate / Deciduous Forest Broad - leaved trees lose their leaves yearly. Some birds migrate.

Tropical Rain Forest Arboreal - tree-dwelling animals Trees / Plants: 1. Canopy 2. Understory 3. Ground

Desert Most desert animals are nocturnal. Estivation - sleeping during hot days. Plants have waxy leaves / spines.

Grasslands (Savanna and Temperate) What are Steppes? Most animals have good vision and speed. Plants have underground stems / survive fires.

Aquatic Biomes Freshwater – Ponds, lakes, streams, rivers, wetlands. Marine – Oceans, coral reefs, estuaries.

Population Dynamics Exponential Growth - as a population gets larger, it also grows faster. Carrying capacity - the maximum number of organisms that an environment can support.

Limiting factors: Factors that affect an organism’s ability to survive. Density dependent factors: Disease Competition Parasites Food & water Space

Density independent factors (abiotic factors): Temperature Storms Floods Drought Habitat disruption (logging, burning, draining swamps, moving in exotic species)

Demography - human population growth Immigration - moving in Emigration - moving out Natality - birth rate Fatality - death rate Growth rate

The End!