Introduction to EcologyChapter 18 Organisms and Their Environment
What is Ecology? • Ecology is the study of interactions among organisms. • Determines relationships among living and nonliving parts of the world within the biosphere, or portion of Earth that supports life.
ORGANISMS AND THEIR ENVIRONMENT • I. ECOSYSTEMS: EVERYTHING IN AN ECOSYSTEM IS CONNECTED. AN ECOSYSTEM INCLUDES: • A. BIOTIC- ALL LIVING THINGS IN AN ECOSYSTEM. • B - ABIOTIC- ALL NON-LIVING THINGS IN AN ECOSYSTEM, SUCH AS SOIL, AIR AND WATER.
Biotic factors • All the living things that inhabit an environment • Organisms depend upon other living things for food and reproduction. • All living organisms affect other living organisms.
Abiotic factors • The nonliving parts of an environment • Include air currents, moisture, light, temperature, and soil.
II. ORGANIZATION OF LIVING THINGS: • A. ORGANISM- _A SINGLE INDIVIDUAL • B. SPECIES- A GROUP OF ORGANISMS THAT CAN REPRODUCE AND PRODUCE FERTILE OFFSPRING.
C. POPULATIONS- GROUP OF INDIVIDUALS OF THE SAME SPECIES_ LIVING IN THE _SAME AREA. • D. COMMUNITIES- SEVERAL DIFFERENT POPULATIONS_ THAT INTERACT IN A SPECIFIC AREA. • E. BIOSPHERE – ALL COMMUNITIES OF THE EARTH.
Single Individual Levels of Organization
Population • Population-a group of organisms of one species that interbreed and live in the same place at the same time • May compete with one another for food, water, mates, and other resources.
A collection of interacting populations. A change in one population in a community will cause changes in the other populations. Community
An ecosystem is made up of the interactions among the populations in a community and the community’s physical surroundings, or abiotic factors. Ecosystem
III. NICHE VS. HABITAT: • A. NICHE IS HOW AN ORGANISM LIVES (WHAT IT DOES) INCLUDING REPRODUCTION, TIME OF DAY IT IS MOST ACTIVE, TYPE OF SPECIES INTERACTIONS, ETC. • B. HABITAT IS WHERE IT LIVES.
Habitat-the place where an organism lives out its life. Niche-the role and position an organism has in its environment. Niche-might reveal what food the organism eats, how far it roams in search of food, where it lives, etc. Occupying different niches reduces competition among organisms Parts of an Ecosystem
IV. FIVE TYPES OF SPECIES INTERACTIONS: • A. PREDATION- ONE ORGANISM (PREDATOR) kills and eats another (PREY). EXAMPLE: LION EATING ZEBRA. • B. COMPETITION- _two species THAT DEPEND ON THE same LIMITED RESOURCE. EXAMPLES: TWO FLOWERS NEEDING POLLINATION, LIONS AND HYENAS NEEDING FOOD. • C. PARASITISM- ONE SPECIES (PARASITE) THAT lives in or on another (HOST) WITHOUT IMMEDIATELY KILLING IT EXAMPLE: TICKS AND A DOG.
D. MUTUALISM- A cooperative partnership BETWEEN TWO SPECIES THAT BENEFITS BOTH. EXAMPLE: HUMANS AND INTESTINAL BACTERIA. • E. COMMENSALISM- A RELATIONSHIP BETWEEN TWO SPECIES where one benefits but the other is not harmed. EXAMPLE: SHARK AND REMORA.
Predator and Prey • Relationship in which one organism kills (predator) and eats another (prey) • Organisms fight for survival
Competition • Two or more species dependant on the same resource.
Parasitism • A symbiotic relationship in which one organism benefits at the expense of another
Mutualism • A symbiotic relationship in which both species benefit. Bees and birds visit flowers in search of pollen and nectar. In the process flowers are pollinated.
Commensalism • Symbiotic relationship in which one species benefits and the other species is neither harmed nor benefited. The Patella gets it food from the plant, the Euklonia, which is not harmed or damaged in the process.
NUTRITION AND ENERGY FLOW • I. ENERGY FLOW IN ECOSYSTEMS • A. ALMOST all ORGANISMS REQUIRE ENERGY FROM THE sun: • 1. DIRECTLY- producers ( MAKES THEIR OWN FOOD-autotrophs) • 2. INDIRECTLY- consumers (DO NOT MAKE THEIR OWN FOOD - heterotrophs)
II. WHO EATS WHAT IN AN ECOSYSTEM? • A. PRODUCER- MAKES ITS OWN FOOD, EXAMPLES - plants, algae, some bacteria • B. CONSUMER- Gets energy by eating other organisms
1. Herbivore_ -EATS PRODUCERS, EXAMPLES - COWS, SHEEP, GRASSHOPPERS • 2. Carnivore - EATS OTHER CONSUMERS, EXAMPLES - LION, WOLVES • 3. Omnivore - EATS BOTH PRODUCERS AND CONSUMERS, EXAMPLES - HUMANS, BEARS, PIGS • 4. Decomposer - BREAKS DOWN DEAD ORGANISMS, EXAMPLES - FUNGI AND BACTERIA
III. HOW ENERGY IS RELEASED? • A. Photosynthesis (chloroplast)- CONVERTS ENERGY FROM THE SUN TO SUGAR 6 CO2 + 6 H2O + SUNLIGHT C6H12 O6 + 6 O2 • B. Respiration (mitochondria)- CONVERTS SUGAR INTO ENERGY • C6H12 O6 + 6 O2 6 CO2 + 6 H2O + ENERGY
IV. ENERGY IS TRANSFERRED THROUGH FOOD CHAINS, FOOD WEBS, AND TROPHIC LEVELS • A. Food chain IS A SERIES OF ENERGY TRANSFERS AS ONE ORGANISM IS CONSUMED BY ANOTHER. EXAMPLE - ALGAE KRILL COD LEOPARD SEAL KILLER WHALE • B. Food Web - MORE THAN ONE FOOD CHAIN LINKED TOGETHER
Trophic Level_ - CHANGE IN USEABLE ENERGY IN A FOOD CHAIN/WEB, • MOST ENERGY AT THE BOTTOM OF A TROPHIC LEVEL
V. WATER CYCLE: • A. SUNLIGHT CAUSES evaporation & transpiration • B. WATER VAPOR COOLS AND forms clouds • C. CLOUDS BECOME saturated and precipitate • D. CYCLE repeats_
Condensation The movement through plants The Clouds form Transpiration Precipitation The rain falls Evaporation The vapor rises
- - H H o + Water Chemical Properties • Two atoms of hydrogen • One atom of oxygen
VI. CARBON CYCLE: • A. CARBON DIOXIDE FROM THE ATMOSPHERE IS USED IN photosynthesis_ • B. Oxygen_ IS RELEASED AS A BY PRODUCT OF PHOTOSYNTHESIS • C. ORGANISMS TAKE IN OXYGEN breath out_ CARBON DIOXIDE. • D. DECOMPOSING OF PLANTS AND ANIMALS PRODUCES carbon dioxide CO2__ • E. BURNING OF _fossil fuels_ PRODUCES CARBON DIOXIDE
VII. NITROGEN CYCLE: • A. NITROGEN GAS FROM THE ATMOSPHERE IS ABSORBED INTO THE ROOTS OF PLANTS BY _nitrogen fixing bacteria_ • B. ORGANISMS EAT plants • C. ANIMALS RELEASE AMMONIA NH4 IN THEIR wastes • AMMONIA IS BROKEN DOWN INTO NITROGEN BY decomposers • OTHER CYCLES: • SULFUR ,CALCIUM, PHOSPOROUS