Ecology Part I

ECOLOGY What is ecology? The study of how living things interact with each other and the environment. Everything is interconnected

BIOTIC FACTORS What are biotic factors? The living parts of an ecosystem Name some biotic factors in this pond ecosystem

ABIOTIC FACTORS What are abiotic factors? The nonliving parts of an ecosystem Abiotic factors include; water, sunlight, air, wind, clouds, temperature, ph (acidity level), soil, and minerals.

Levels of Organization Organism is an individual species in an ecosystem. Species is a group of similar organisms that can mate with each other and produce fertile offspring.

Levels of Organization Population is all the members of a particular species that’s living in a particular area.

Levels of Organization Community collection of different populations that live together in a certain area.

Levels of Organization Ecosystem is the community (all living organisms) living together with their abiotic factors (physical environment).

Levels of Organization Biome group of ecosystems that have the same climate and dominant communities Biosphere group of ecosystems that have the same climate and dominant communities (ALL organisms found here)

Levels of Organization Can you pick out the levels of organization in this ecosystem? Name the examples of organism, species, population, community, and ecosystem. Organism – ONE striped fish Species – all striped fish Population –all striped fish in this body of water on september, 2013 Community – all other fish in body of water Ecosystem – living and nonliving (ex: water, co2, temp, pH level, oxygen level, salinity of water)

Habitat versus Niche Habitat = where a species lives ALL physical and biological resources available to a species Different than an ecosystem Niche = role a species plays in the ecosystem Ex: how it uses its resources Ex: number of offspring Ex: time of activity (nocturnal, diurnal Physical – pH level, temperature, climate, soil type, rainfall Biological – food, water, shelter Each animal has its own “habitat” – all organisms’ habitats make up an ecosystem

Beaver Habitat and Niche Describe the habitat and niche: Habitat includes (biological and physical factors/abiotic)  biological (what it needs to survive): food source (prey), shelter, water, trees (for shelter? Or home perhaps)….. Physical/abiotic: water, air, trees, mud/soil, temperature/climate Niche includes (occupation)  creates ponds (habitat), causes flooding, active at night, kills trees, migrates, creates new ecosystem by making ponds (Ex) --- can harm home of other organism by creating a “new ecosystem when making a pond”

Generalists and Specialists species with broad niches tolerate a range of conditions use variety of resources Specialists  Narrow niches Cannot tolerate wide ranges of conditions Require certain foods, climate, etc. Can you think of an example of each?

Energy Transfer in Ecosystems All organisms need a constant supply of energy to survive! Energy flows in ecosystems! Amount of energy an ecosystem receives and the amount transferred from organism to organism effects an ecosystem’s structure

The Producers Autotrophs Plants, protists, and bacteria Producers- capture energy and use it to make organic molecules What are organic molecules?

The Producers Photosynthetic- use solar energy to power production of organic molecules Plants, algae, cyanobacteria Chemosynthetic- use energy stored in inorganic molecules to produce organic molecules Sulfur bacteria- hot springs/deep sea vents

The Consumers ALL animals! Heterotrophs Consumers- cannot manufacture own food; rely on other organisms for energy and food supply

Consumers: Herbivores Herbivore- obtain energy by eating only plants (producers)

Consumers: Carnivore Carnivore-eats other animals (consumers –ex:herbivores) What other consumers might this lion eat?

Consumers: Omnivores Omnivore- eats both (plants) producers and consumers (animals)

Consumers: Decomposers Decomposers-organisms that break down dead and decaying organisms Fungi & Bacteria Last link in any food chain! Make molecules available again for autotrophs (soil & water)

Consumers: Detrivores Detrivores-feed on plant and animal remains and other dead matter Dead matter = detritus

Energy Flow One organism eats another, molecules are metabolized, and energy is transferred Energy is non-cyclic, unidirectional flow Organisms are grouped in an ecosystem according to how they obtain energy Sun/inorganic cmpds  autotrophs (producers)  heterotrophs (consumers)

Food Chains Food Chain-single pathway of feeding relationships among organisms in an ecosystem that result in energy transfer. Feeding relationships in a real ecosystem are too complex! Consumers eat more than one type of food! More than one species may eat the same organism!

Food Chain

Food Web Food Web- interrelated food chains in an ecosystem. Links several food chains together Removal of one species affects many other species!

Energy Transfer Biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem Biomass- organic material produced in an ecosystem by making organic molecules. What organisms produce organic molecules? ONLY energy stored as biomass is available to other organisms in an ecosystem

Energy Transfer Energy pyramids or food pyramids show the amount of energy stored as organic material in an ecosystem. LOW percentage of energy is transferred from one level to the next Total mass of any feeding level in a food chain is ONLY 10% of the total mass of the level below it!

Energy Transfer Each step in food chain/web/pyramid = trophic level Producers  1st level Consumers  2nd , 3rd , or higher trophic levels Consumers depend on the tropic level below it for energy Ultimate source of energy = SUN

Energy vs. Nutrient Transfer Energy  continual supply from outside ecosystem Energy used, then lost NOT recycled Nutrients  RECYCLED via ecosystem

Why is Energy Decreasing? Some organisms escape without being eaten When an organism is eaten, some molecules will be found in a form that consumers cannot use NO transfer of energy is 100% efficient! Some energy will be lost as heat

Measuring Productivity Gross Primary Productivity- rate at which producers in an ecosystem capture the energy of sunlight by producing organic compounds. Photosynthetic producers use energy and carbon dioxide to make sugars Use these sugars as food source and to store energy in a form that they can use What might the producers need energy for?

Measuring Productivity Net Primary Productivity- ecologists measure the rate at which biomass accumulates Gross Primary Productivity – Rate of Respiration= Net Primary Productivity Vary between ecosystems Variations in light, temperature, precipitation, and availability of nutrients affect productivity Increase in variable will cause an increase in productivity