Ecology Test 4

primary producers

photosynthesizers (plants, algae); chemoautotrophs; their detritus

1st consumer level

herbivores, detritivores, fungi, heterotrophic prokaryotes, heterotrophic microbial eukaryotes

higher consumer levels

predators, fungivores, bacterivores

primary production

the production of new organic matter, or biomass, by autotrophs

respiration

converts energy stored in sugar into ATP; reverse of primary production

nutrients

• boost primary production

• productivity is higher in higher fertility soils

• productivity is lower in lower fertility soils

Kuparuk Ridge

experiment that tested whether nutrients help plant production

• demonstrated that nutrients do indeed regulate primary production

limiting nutrient

nutrient that is least available relative to demand; nutrient is in limited supply

• sometimes can be water or life but is usually water

adding nutrients

addition of a limiting nutrient increases productivity

• addition of a non-limiting nutrient will not increase productivity (plants have enough of it already)

• increasing the supply of a limiting nutrient can cause a different nutrient to become limiting

borreal forest experiment

Dry meadow

• water was a limiting factor as well as nitrogen (primary) and phosphorous

Wet Meadow

• phosphorous and nitrogen were a co-limiting factor and had and additive effect

pelagic zone

the primary producer is phytoplankton

Shallower waters

the primary producer is benthic algae

lakes

primary production is typically limited by phosphorous

• phosphorous is harder to get in comparison to nitrogen (comes from atmosphere)

streams, rivers, estuaries, oceans

primary production is often limited by nitrogen

• nitrogen fixing cyanobacteria aren’t found in a lot of other kind of places

• there is enough phosphorous in those places that has been weathered out of geological service

micronutrients

nutrients that are essential but not needed in high amounts

shallow coastal waters and areas of upwelling

the areas with highest production in areas with greatest nutrient supply

open ocean away from tropics

there is low production

• thermocline prevents nutrients from being transported from deep water to the surface where light is available