Ecology: Biology 22 Lecture

Ecology

BIOLOGY 22 LECTURE

Lecture Content • Ecology defined… • Ecological Heirarchy • The Ecosystem – Energy Flow in Ecosystems – Population Interactions – Material Cycling

• Biomes

Ecology is… • The study of the interactions between organisms (biotic factors) and their physical environment (abiotic factors) Coined by • Gr. oikos = household; logos = study

Ernst Haeckel

Ecologists… • Collect information about organisms & their environment • Observe and measure interactions • Look and seek to explain patterns in interactions

Ecological Heirarchy Levels of Organization

Ecological Heirarchy: Population • Group of similar organisms that can breed and produce fertile offspring • Composed of a species

Ecological Heirarchy: Community

• An assemblage of different populations that live together

Ecological Heirarchy: Ecosystem • Collection of organisms (biotic) that live in a place with the nonliving environment (abiotic) • Basic Ecological Unit

Ecological Heirarchy: Biome • Group of ecosystems with the same climate and dominant communities

Tropical rain forest

Temperate grassland

Temperate forest

Tundra

Tropical dry forest

Desert

Tropical savanna

Temperate woodland and shrubland

Northwestern coniferous forest

Mountains and ice caps

Boreal forest (Taiga)

Ecological Heirarchy: Biosphere • The part of the earth where life exists including land, water, air, and atmosphere

The Ecosystem • Basic ecological unit • Self-contained, interdependent system of living and nonliving things • Requirements: 1. Energy source and flow 2. Populations 3. Cycling of materials

The Ecosystem: Energy Flow • The ultimate source of energy is the sun • Simplified flow: Sun  Autotrophs  Heterotrophs • Represented by food chains & food webs • These webs are composed of several Autotrophs (producers): Create own food through the sun’s aid trophic levels (producers & Heterotrophs (consumers): consumers) Acquire food from sources other than the sun

The Ecosystem: Energy Flow

The Ecosystem: Food webs Food webs summarize the movement of food through a community. Food webs are composed of many specific sequences of who eats whom, known as food chains.

Key players in food webs: producers, primary consumers, secondary consumers

Sample food web: Rainforest Ecosystem

Population Interactions • Also known as symbioses (living together) • Ecological relationships between members of different species

Material Cycling • Although an ecosystem needs a continuous supply of energy from outside itself, its raw materials are continuously cycled and reused: – Carbon-hydrogen-oxygen – Water – Nitrogen

Material Cycling: Carbon

Material Cycling: Water

Material Cycling: Nitrogen

Biomes • Composed of several ecosystems sharing the same climatic conditions • Make up the entire biosphere (part of the earth where life exists) • Terrestrial (Land) and Aquatic

Biomes: Terrestrial (Land)

Biomes: Aquatic • Marine 1. Oceans: largest & most diverse ecosystem 2. Coral reefs: warm shallow waters that line continents 3. Estuary: connect marine & freshwater biomes

• Freshwater 1. Lakes: enclosed by land; still water 2. Wetlands: still water; may have high salt content 3. Rivers & streams: running water

Ocean Zonation

one z tic o h P one z ic t o h Ap

Ocean Zonation

Reef Formation Fringing Reef

Volcano rises above sea level Underwater volcano Fringing Reef

Atoll

Lagoon

Lagoon No land protrudes

Volcanic island subsides

End