Principles of Ecology 7-1

The Study of Ecology A look at how individual organisms interact with each other and with their environment

Living and Nonliving The nonliving parts of the environment are called the abiotic factors air currents, temperature, moisture, light, soil often determine which species survive in a particular environment The living organisms that inhabit an environment are called biotic factors

Abiotic factor to skin…

Levels of Organization Ecologists have organized the living world into levels the organism by itself (its species) populations – group of organisms communities – interacting populations ecosystems – interacting populations + the abiotic factors Biomes - group of ecosystems (same climate, etc.) biosphere – part of Earth that can support life

Modern Ecological Research Observing (->) What species live here? Experimenting Test your hypothesis Modeling Helps make predictions on eco- data Ex. “At this rate, the bald eagle will be extinct by the year 2020”

Example Temperatures too low or too high affect the survival of the flies What is the optimal temperature for their survival?

Organisms Autotrophs - (Producers) Produce their own food from sun: Photosynthesis water + carbon dioxide + light energy  Sugar + Oxygen Light energy H2O + CO2 === C6H12O6 + O2 Plants, algae, certain bacteria

Autotrophs

Heterotrophs - Consumers herbivores (eat only plants) Cows, deer carnivores (eat only meat) Snakes, owls omnivores (eat both plants and meat) Humans, bears scavengers eat dead matter Vultures, crabs decomposers (break down organic matter) Earthworms, bacteria

Herbivore

Carnivore

Omnivore

Scavengers

Decomposers

Energy Flow Flows through an ecosystem in one direction SUN  Autotrophs  Heterotrophs Energy Flow is represented by -Food chains -Food webs

Food Chain Nutrients and energy move from autotrophs to heterotrophs and eventually to decomposers. Relatively rare because species can be eaten by more than one thing.

Food Web -Shows the complex feeding relationships between organisms -Food webs are more realistic than food chains -Each organism represents a feeding step, or trophic level

TROPHIC LEVELS -Producer -Primary consumer -Secondary -Tertiary -Decomposer

Trophic levels Each trophic level depends on the one before it for energy.

Higher trophic levels are layers on top of one another Only 10% of energy / matter is transferred between levels Can illustrate: Energy Numbers Biomass (total weight of living matter)

The 10% rule… AMOUNT OF ENERGY FROM ONE TROPHIC LEVEL TO THE NEXT… PRODUCER PRIMARY SECONDARY CONSUMER CONSUMER

Survival Relationships Most species survive because of relationships with other species Symbiosis – close, permanent relationship between organisms of different species commensalism mutualism parasitism

commensalism

mutualism

parasitism Filarial worms (causes Elephantitis). Spread by mosquitos passing the worm larvae into bloodstream

Predator / Prey Relationship Predators seek out and eat other organisms Prey are the animals that are eaten – the unlucky ones!

Organisms Habitat – place where an organism lives shared – creates competition Niche – strategies and adaptations used by an organism to get food, shelter, and to reproduce advantageous to occupy a different niche than others in same habitat

Elephant vs. Lion Click me! Squirrel and Mongoose vs Cobra Click THIS!