4.1 Species, communities and ecosystems

From Chapter 4: Ecology, minus Chi Squared Test

ecology

the study of the relationship between living organisms, or between living organisms and their environment

biotic factor

living factors in an ecosystem, such as the plants and animals

abiotic factor

non-living factors such as pH, water, wind, soil, etc.

ecosystem

the interaction between biotic components (e.g. communities) and its abiotic environment (e.g. habitat)

habitat

the abiotic environment, a location where a species/organism lives

community

a group of populations living and interacting in a particular area

population

a group of organisms of the same species that live in a particular area at the same time

species

a group of organisms that can potentially interbreed and produce fertile offspring

examples of interbreeding

liger (lion + tiger), mule (donkey + horse), zorse (zebra + horse)

mode of nutrition

how an organism obtains organic molecules and energy

autotroph

Producers in the food chain, "Auto" means self, "trophic" means nutrition
Organisms which synthesize its own organic molecules from simple inorganic substances, derived from the abiotic environment

photoautotroph

an autotrophic organism which makes organic compounds using energy from the sun

chemoautotroph

an autotrophic organism which makes organic compounds using energy from the oxidation of chemicals

heterotroph

Consumers in the food chain, "Hetereo" means different, "trophic" means nutrition
Organisms which obtain organic molecules from other organisms instead of producing their own

mixotroph

organisms which uses both autotrophic and heterotrophic modes of nutrition
example: euglena gracilis

herbivores

consumers that feed principally on plant matter
example: cows, sheep, rabbits

carnivores

consumers that feed principally on animal matter
example: wolves, tigers

omnivores

consumers that have feed on both plant and animal matter
example: pandas, humans

scavanger

opportunistic animal, consumer that principally feed on dead and decaying carcasses rather than hunting living pray
example: hyenas, vultures, crows

saprotrophs

a type of heterotrophic feeding, organism which live in/on inorganic matter and ingests it through external digestion by secreting digestive enzymes and absorbing the products
example: bacteria, fungi, mold

detritus

dead, particulate organic matter (e.g. decaying organic material and fecal matter)

humus

a specific form of detritus, decaying leaf litter intermixed with the topsoil

detritivores

a type of heterotrophic feeding, organism which ingests non-living organic matter through internal digestion
example: dung beetles, earthworms, snails, crabs, millipede

consumers

a type of heterotrophic feeding, organism which ingests organic matter which is living or recently killed

primary consumers

herbivores, feed only on autotrophs (producers)

secondary consumers

carnivores, feed on primary consumers

tertiary consumers

carnivores, feed on secondary consumers

symbiotic relationship

symbiosis means "living together", close interaction between species in which one species lives in or on the other

mutualism

a symbiotic relationship where both organisms benefit
example: spider crab and algae

commensalism

a symbiotic relationship where one organism benefits and the other is unaffected
example: a bird nest in a tree

parasitism

a symbiotic relationship where one organism benefits and the other is harmed
example: mosquito and human

predator-prey relationship

interaction between two organisms in a community where one organism hunts and feeds on the other
example: wolf and elk/deer (Yellowstone National Park example)

nutrients

material required by an organisms, include elements such as carbon, nitrogen and phosphorus

inorganic nutrients

minerals, water, etc. finite supply on Earth

nutrient cycling

The circulation of chemicals necessary for life, from the environment (mostly from soil and water) through organisms (consumers and producers) and back to the environment.

energy availability

one of the three main components in a sustainable ecosystem, light from the sun which provides an initial energy source

nutrient availability

one of the three main components in a sustainable ecosystem, saprotrophic decomposers cycle inorganic nutrients through the environment

recycling of wastes

one of the three main components in a sustainable ecosystem, certain bacteria detoxify harmful waste byproducts

mesocosm

enclosed environments that allow a small part of a natural environment to be observed under controlled conditions

reproductively isolated

populations whose members do not mate with each other or who cannot produce fertile offspring