Ecosystems + Energy Flow

Definitions

Biotic Factor - Living factors within an ecosystem

Abiotic Factor - Non-living factors within an ecosystem

Producer - Organisms that can photosynthesise to manufacture their own food (plants)

Consumer - Organisms that feed off other organisms to obtain food

Photosynthesis - A process through which glucose (energy) is manufactured

Parasite - An organism that lives in or on another organism, causing it harm

Pollinator - An organism that transfers pollen from the male to the female part of a plant

Predator - An organism that kills and feeds on prey

Prey - An organism dies by a predator

Adaptation - A feature that enables an organism to survive in its environment

Zone of Tolerance - The range of an abiotic factor that an organism can survive in

Atmospheric Nitrogen - Nitrogen that is found in the atmosphere

Mutualism - A relationship in which both organisms benefit

Biodiversity - The variety of species in an ecosystem

Eutrophication - The process in which nutrient levels increase in a waterway, resulting in increased algal growth and decreased oxygen levels

Keystone Species - A species that plays a crucial role in its ecosystem

Germinate - To grow and put out shoots

Intensity - How much heat is released from a fire front

Ecosystems

  • An ecosystem is formed by organisms interacting with each other and their non-living environment in a balanced way

Source of energy for ecosystems

  • Ecosystems require energy from an external source

  • The ultimate source of energy for all ecosystems is the sun

Photosynthesis

  • carbon dioxide + water = glucose + oxygen

Competitors compete for resources

  • Competition often happens when organisms share the same limited resources in the same ecosystem

  • E.g. members of the same species may compete for a mate

Predators and prey keep each other in balance

  • Predators must adapt to efficient hunting if they are to catch food to survive

  • Prey must adapt to escape predators for their species to continue to survive

  • Interactions between predator and prey are crucial for stabilising ecosystems

  • E.g. fox and rabbit

Pollinators and Plants

  • Flowering plants have male and female sex organs

  • In order for fertilisation to occur, they need a pollinator

  • This relationship is called mutualism

Abiotic factors affect what can live in an ecosystem

  • Abiotic factors are chemical and physical factors within an ecosystem

Organisms have adaptations to abiotic factors

  • Structural - A feature on the body that helps the organism to survive

  • Behavioural - The way an organism responds to the environment

  • Physiological - A process inside an organism’s body that helps it survive

Coral bleaching is caused by abiotic factors

  • If water temperature or pollution increases, then the coral will expel the algae and become bleached, and eventually the coral will die

Nitrogen

  • Cycles through ecosystems

  • Nitrogen is found in amino acids

  • Nitrogen makes up 78% of the air on Earth

Nitrogen cycles from the atmosphere

  • Plants cannot use atmospheric nitrogen; they need to obtain nitrogen from the soil in the form of nitrate

Types of Bacteria

  • Decomposers - Convert nitrogen chemicals from organic matter into ammonia

  • Nitrogen-Fixing - Bacteria convert nitrogen from the air into other compounds in the soil

  • Nitrifying - Bacteria convert ammonia into nitrates and nitrites

  • Denitrifying - Bacteria convert nitrate into nitrogen gas

Other elements also cycle through ecosystems

  • Carbon, oxygen, hydrogen, and phosphorus are other important elements that cycle through ecosystems

Eutrophication

  • As oxygen levels drop, aquatic species are affected