The Study of Interactions between Organisms and their Environment ECOLOGY The Study of Interactions between Organisms and their Environment

Ecology Vocabulary Population: a particular species in an area Community: a group of populations in an area Ecosystem: a community plus its non-living (abiotic) environment Biosphere: all regions of the planet inhabited by populations Habitat: The place a population lives Niche: the role of the population in the environment (what you eat, what you do)

ECOSYSTEM FACTORS BIOTIC: Living ABIOTIC:Non-living AUTOTROPHS (producers)ex. plants HETEROTROPHS (consumers)ex. Animals an omnivore ,a carnivore and a herbivore are all heterotrophs DECOMPOSERS ex. Bacteria, fungi ABIOTIC:Non-living temperature, sunlight, water, minerals

Trophic Levels

Trophic Levels Primary Producers: The autotrophs that capture energy to make food (Plants) Primary Consumers: heterotrophs that eat autotrophs (herbivores) Secondary Consumers: heterotrophs that eat other heterotrophs (carnivores) Higher Level Consumers: carnivores that eat other carnivores Decomposers: consumers of dead organic material ( Bacteria, Fungi)

ENERGY FLOW Food chains: a specific energy pathway Food webs: complex energy interactions in found in an ecosystem. Energy pyramids: representation of the total energy available to a trophic level.

FOREST FOOD WEB

Arctic Marine Food Web

Biomass Pyramid

Energy Pyramid

Kruger Park Battle

Growth of Populations Exponential Growth : the maximum possible growth rate of a population Carrying Capacity of the Environment: The maximum population that a particular environment can support Limiting Factors : those environmental factors that keep a population at the carrying capacity, like food, predators, amount of water, how much land there is

Population Growth over Time

Exponential growth can lead to massive die-off In 1944, 20 reindeer were brought to St. Matthew Island. Initially there were abundant food sources, and the reindeer population increased dramatically. There were no predators to cull the population. However, about 20 years later, the reindeer had overshot the food carrying  capacity of the island, and there was a sudden, massive die-off.  About 99% of the reindeer died of starvation. Exponential growth can lead to massive die-off

Carrying capacity of the Environment

Community Interaction competition

Predator-Prey Interactions Predators : Organisms that catch and consumed other organisms Prey : organisms that get consumed. Top Predator : the organism within a food chain or web that is not eaten by any other organism.

Predation

Predator – Prey Dynamics

Symbiosis When TWO or more species interact so closely that one or more of them is NECESSARY for the other’s survival. Examples: Coral and zooxanthellae algae Fig trees and fig wasps Tape worms and humans Fleas and hairy mammals

Mutualism Both organisms BENEFIT from the interaction Coral and Zooxanthellae Red billed oxpecker feeds on the ticks Off the Impalas coat (Africa) Clownfish and Sea Anemone

Crocodile and plover mutualistic relationship Crocodile and plover mutualistic relationship. Plover cleans crocodiles teeth.

Commensalism – one IS HELPED but the other is NOT harmed Ex. Birds nest in trees

Parasitism One organism BENEFITS The other is HARMED

Predator Prey Co-evolution Protection from Predation (for prey) Poison : the production of toxins Camouflage : protective coloration Mimicry: look alikes Adaptations to overcome protections (for predators) Intolerance to poisons : immunity Use of senses other than sight: hearing, smell

Co-Evolution Predator /prey interactions WARNING coloration says, “Don’t mess with me !!” POISON IVY – protected from herbivores

Camouflage coloration PROTECTIVE catipillar Stick insects found in Australia

Mimicry Similar colors Similar DEFENSES Wasp bee

Mimicry- Fooled Ya! King snake (not poisonous) Coral snake (VERY poisonous) Red next to yellow you’re a dead fellow

Ecological Succession The natural progression of SPECIES and their EFFECTS on the environment PIONEER Species – the first to invade a new environment (bare rock) MODIFICATIONS by the first group leads to the second, the second the third, etc. The CLIMAX species will end the succession.

Forest Succession

Lake Succession LAKE community Sedimentation due to EROSION SWAMP community forms Eventually a FOREST community may form

Nutrient Recycling Carbon and Oxygen: CO2, O2 (AIR) Water: H2O (SOLID, LIQUID, GAS) Nitrogen: N2 (AIR) Other Minerals : MAGNESIUM, CALCIUM, IRON, ZINC, COPPER, SILICA, ETC.

Carbon Cycle Atmospheric CARBON DIOXIDE Autotrophs CHANGE TO SUGAR C6H12O6 Heterotrophs CHANGE TO CO2 AND ORGANIC MATERIALS. Decomposers BREAK DOWN ORGANIC MATERIALS TO CO2 Burning of FOSSIL FUELS

Water Cycle Evaporation LIQUID TO WATER VAPOR Transpiration EVAPORATION THROUGH PLANTS Condensation and Precipitation RAIN, SNOW, SLEET, HAIL etc. Runoff and Groundwater INFILTRATION Liquid water on the surface LAKES, STREAMS, OCEANS etc.

Nitrogen Cycle Nitrogen in the Atmosphere N2 GAS Nitrogen Fixers BACTERIA ON PLANT ROOTS Plants and Animals PROTEINS, UREA Decomposers PRODUCE AMMONIA Nitrifying Bacteria NH4 -> NO2, NO3 Denitrifying Bacteria NO3-> N2 GAS

Other Minerals Rocks and Soil CONTAIN MINERALS Erosion RELEASES MINERALS Water dissolves MINERALS Plants and Algae uptake MINERALS Animals consume PLANTS AND ALGAE Decomposers LEAVE MINERALS IN SOIL