Unit 2 Ecology 2 1 INTRODUCTION TO ECOLOGY

Unit 2: Ecology 2. 1 INTRODUCTION TO ECOLOGY AND ECOSYSTEMS

Ecology How organisms interact with each other and their environment

Levels of Ecological Organization

Different populations that live together in a specific place. Major biological communities based on temperature and moisture. Ex: tundra, aquatic, deserts, forest and grasslands. One species that lives in the same place at the same time. All living and non-living things that interact as a system in a specific place. The combined portions of the planet in which all of life exists. Includes: land, water, atmosphere.

Energy Role in an Ecosystem The sun provides the primary energy in an ecosystem! Autotrophs/Producer: “self feeders” they produce their own energy through photosynthesis. ◦ Example: plants and photosynthetic bacteria Heterotroph/Consumer: “different feeders” they are the consumers who have to ingest food for energy ◦ Example: animals Decomposers: break down biological materials to return energy to the environment ◦ Example: fungus and bacteria

Niche The fundamental role of a species within an ecosystem. Basically, it’s a way of life. Competitive Exclusion No two species can occupy the same niche! ◦ Two species completing for the same limiting resource cannot coexist at constant population values.

Niche Examples: Niche partitioning by warblers and barnacles at high and low tide

Feeding Relationships ENERGY FLOWS THROUGH AN ECOSYSTEM IN ONE DIRECTION: FROM THE SUN OR INORGANIC COMPOUNDS TO AUTOTROPHS (PRODUCERS) AND THEN TO VARIOUS HETEROTROPHS (CONSUMERS)

Food Chains Series of events in which one organism eats another. ◦ Shows a single path Arrows always point in the direction of energy flow! Consumers are further classified based on what they eat. ◦ Primary consumer: herbivore (ex: a bug) ◦ Secondary consumer: carnivore (ex: salmon) ◦ Tertiary consumer: carnivores that eat other carnivores (ex: bear) The first organism in a chain is always a producer, the second organism is always the primary consumer that eats the producer, the third organism is a secondary consumer that eats the primary consumer, and so on and so forth.

• Each step in a food chain or web is called a trophic level. Producers always make up the first trophic level, while consumers make up the second, third, fourth or higher trophic levels. • Each consumer depends on the trophic level below it for energy.

Food Web Shows the complex interaction of all the organisms within the ecosystem. ◦ Shows the many paths that energy can be transferred through an ecosystem.

Chemosynthesis: The synthesis of organic compounds by bacteria or other living organisms using energy derived from reactions involving inorganic chemicals, typically in the absence of sunlight. ◦ Some bacteria are able to feed on hydrogen sulfide, a noxious chemical

Hydrothermal Vents An opening in the sea floor out of which heated mineral rich water flows ◦ Found along mid ocean ridges where tectonic plates are spread apart ◦ Seawater circulates deep in the ocean’s crust and becomes superheated by hot magma

http: //www. hhmi. org/biointeractive/how-giant-tube-worms-survive-at-hydrothermal-vents

Ecological Pyramids

Energy Pyramid Shows how energy is transferred based on the trophic level. 90% of the energy that an organism gets is used to sustain life or is lost to the environment as heat. The other 10% gets transferred up the trophic levels. ◦ This means an ecosystem can support more primary consumers than tertiary consumers.

Energy Pyramid

Biomass Pyramid The total amount of living tissue within a given trophic level is called biomass. Biomass is usually expressed in terms of grams of organic matter per unit area. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

Biological Magnification: The process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals, or humans. ◦ Toxins build up to higher levels as you move up the food chain. ◦ The concentration of toxins at the top of the chain increases tremendously compared to toxin levels at the bottom of the chain.

http: //sciencelearn. org. nz/Contexts/Toxins/Sci. Media/Interactives/Bioaccumulation-in-the-sea