Ecology Honors Biology What is Ecology? Greek Origin OIKOS = Household LOGOS = Study of Ecology = The study of the house/environment in which we live. ECOLOGY: Levels of Organization - a hierarchy of organization in the environment in the environment Organism Population Community Biosphere Ecosystem Organism organisms of one species interbreedinterbreed compete with each other for resourcescompete with each other for resources Population interacting populationsinteracting populations inhabit a common environmentinhabit a common environment are interdependentare interdependent Community Ecosystem Populations in a community interacting with abiotic factors Biosphere life supporting portions of Earth composed of air, land, fresh water, and salt water. The highest level of organization Habitat The type of environment in which an organism lives. A species has adaptations that allow it to function in its habitat. An ecosystem contains several habitats Tree tops, bottom of lake, shore. Levels of Organization Recall the Penguins. What populations, communities, habitats, and ecosystems existed in the penguin scenario? Ecology is study of interactions between non-living components in the environment light water wind nutrients in soil heat solar radiation atmosphere, etc. AND AND Living organisms Plants Animals microorganisms in soil, etc. To study Ecology involves For non-living (abiotic) Climatology Hydrology Oceanography Physics Chemistry Geology soil analysis, etc. For living (biotic) Physiology Taxonomy Animal behavior Mathematics (population studies) etc. Ecology views each locale as an integrated whole of interdependent parts that function as a unit. tundra caribou The Interdependent Parts Non-living Dead organic matter Nutrients in soil and water Producers Green plants Photosynthetic protists (algae) Photosynthetic bacteria (cyanobacteria) The Interdependent Parts Consumers Animals (Herbivores, Carnivores, Omnivores) Heterotrophic Protists Decomposers Fungi Bacteria Producers Autotrophs- Obtain energy from nonliving sources Photoautotrophs energy from sunlight Chemoautotrohs energy from inorganic chemicals (bacteria only) Autotrophs use this energy to build biomolecules used for cellular processes Consumers Heterotrophs- consume other organisms for food (energy) Ultimate source of all cellular energy: the sun Herbivores (primary consumers)- consume plants Carnivores (secondary, tertiary, quaternary consumers) eat animals Decomposers Heterotrophs that break down dead organic matter Important for recycling nutrients in the environment K+, Fe+2, NO3-, NH4+ Nutrients released from dead matter are returned to the soil. Often taken up by plant roots and returned to the food web. Energy Flows through Food Chains All living things require energy to do work Cells use chemical energy energy stored in the bonds of molecules When bonds are broken, free energy is released and used to do work. Build cell parts, transport of nutrients, muscle contractions Energy Flows through Food Chains Autotrophs use light energy to build molecules of sugar (chemical energy) Autotrophs and heterotrophs break down sugars using cellular respiration. This releases free energy. Energy Flows through Food Chains Herbivores Energy Flow First Law of Thermodynamics energy cannot be created or destroyed. Conservation of Energy Trophic Levels Each link in a food chain is known as a trophic level. Represent a feeding step in the transfer of energy and matter in an ecosystem. Trophic Levels Biomass- the amount of organic matter comprising a group of organisms in a habitat. As you move up a food chain, both available energy and biomass decrease. Energy is transferred upwards but is diminished with each transfer (the 10% rule). Producers- Autotrophs Primary consumers- Herbivores Secondary consumers- small carnivores Tertiary consumers- top carnivores ENERGY BIOMASS Relationships in Ecosystems Symbiotic Relationships 3 Types of symbiosis: Commensalism Parasitism Mutualism Commensalism- one species benefits and the other is neither harmed nor helped Ex. orchids on a tree Epiphytes: A plant, such as a tropical orchid, that grows on another plant upon which it depends for mechanical support but not for nutrients. Symbiosis Commensalism- polar bears and cyanobacteria Symbiosis Parasitism- one species benefits (parasite) and the other is harmed (host) Symbiosis Parasitism- Ex. lampreys, leeches, fleas, ticks,tapeworm Symbiosis Mutualism- beneficial to both species Ex. cleaning birds and cleaner shrimp Symbiosis The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos. The plover has also been observed taking leeches from the open mouths of crocodiles! In this association the plover receives a supply of food and the other animal rids itself of unwelcome pests Mutualism- Ex. lichen Symbiosis Clown fish with anemone Which relationship? Clown fish gets protection Anemone is unaffected Antelope with Oxbird Which Relationship? Antelope gets rid of parasites Oxbird gets a meal Cattle with cattle egrets Which Relationship? Cattle stir up insects as they eat grass Egrets hang around and eat insects Acacia plant with ant galls Ants lay eggs on acacia tree Acacia covers the infected area with brown flesh (gall) Moray Eel with Cleaner Fish Moray Eel gets a clean mouth Cleaner Fish gets a meal Type of relationship Species harmed Species benefits Species neutral Commensalism Parasitism Mutualism = 1 species Cycling maintains homeostasis (balance) in the environment 3 cycles to investigate: 1. Water cycle 2. Carbon cycle 3. Nitrogen cycle Nutrient Cycles Evaporation, transpiration, condensation, precipitation The Water Cycle Photosynthesis and respiration cycle carbon and oxygen through the environment. The Carbon Cycle Atmospheric nitrogen (N 2 ) makes up nearly 78%-80% of air. Organisms can not use it in that form. Lightning and bacteria convert nitrogen into usable forms. The Nitrogen Cycle Only in certain bacteria and industrial technologies can fix nitrogen. Nitrogen fixation-convert atmospheric nitrogen (N 2 ) into ammonium (NH 4 + ) which can be used to make organic compounds like amino acids. N 2 NH 4 + The Nitrogen Cycle Nitrogen-fixing bacteria: Some live in a symbiotic relationship with plants of the legume family (e.g., soybeans, clover, peanuts). The Nitrogen Cycle Some nitrogen-fixing bacteria live free in the soil. Nitrogen-fixing cyanobacteria are essential to maintaining the fertility of semi-aquatic environments like rice paddies. The Nitrogen Cycle Atmospheric nitrogen Lightning Nitrogen fixing bacteria Ammonium Nitrification by bacteria NitritesNitrates Denitrification by bacteria Plants Animals Decomposers Nitrogen Cycle Toxins in food chains- While energy decreases as it moves up the food chain, toxins increase in potency. This is called biological magnification Ex: DDT & Bald Eagles