Question | Answer |
Anything that photosynthesizes is called | a producer |
A rabbit or mouse is an example of | a primary consumer |
The top predator in an ecosystem would be called | a tertiary consumer |
The snake that eats the mouse is | a secondary consumer |
bacteria or fungi that break down organic material and replenish nutrients to the soil | decomposer |
detritus feeders or detrivores | feed on waste or dead bodies ex)vulture |
prectentage of usable chemical energy that is transferred a biomass from one trophic level to the next. | ecological efficiency |
biomass | dry weight of organic matter contained in organisms. transferred from 1 trophic level to the next. |
gross primary productivity (GPP) | rate at which an ecosystems producers convert solar energy into chemical energy. usually measure in kcal/m2/yr. |
net primary productivity (NPP) | rate at which an ecosystems producers convert solar energy into chemical energy minus (-)rate at which they use some of this stored chemical energy for respiration. (NPP= GPP-R) |
NPP is greatest... | where there is more solar radiation available or in bodies of water where there is a large nutrient flow |
humans have intervened in this cycle by cutting down forests and burning fossil fuels | carbon cycle |
a key component of nature's thermostat is | carbon |
Most of out atmosphere is | nitrogen |
bacteria and blue-green algae convert N2 to NH3 (ammonia)and then to ammoniumn ions for the plants | nitrogen fixation |
nitrification | ammonia is converted to nitrites (NO2-) and then nitrates (NO3-). This process naturally occurs in the environment, where it is carried out by specialized bacteria. |
bacteria in moist environments convert NH3 and NH4+ back into nitrate ions and then into N2 and N20 gases | denitrification |
We intervene in the nitrogen cycle by | burning fossil fuels and contributing to acid deposition, by added nutrients from livestock waste and fertilizer to soil that also runs off into bodies of water |
This nutrient doesn't cycle through atmosphere | Phosphate |
Sulfur enters the atmosphere naturally by | active volcanoes, anaerobic (does not need O2) decomposers in swamps, sea spray, dust storms and forest fires |
Humans have added sulfur to the atmosphere by | burning coal with sulfur for electricity, refining petroleum to make gasoline, smelting mineral ore into metal. All of this releases sulfur compounds into atmosphere and then it comes back to the surface in acid rain. |
a positive feedback loop is | a change further in the same direction in a system.sometimes referred to as vicious cycles,"A produces more of B which in turn produces more of A". |
a change in a system in the opposite direction | negative feedback loop |
species only found in 1 area are | endemic species |
species richness | # of species within a community |
species evenness | abundance of individuals found within a species |
characteristics of r-selected species or r-strategists | tend to have many, usually small offspring with little or no parental care required. tend to be opportunistic species. examples: bacteria, rodents, frogs, insects |
characteristics of K-selected species or K-strategists | reproduce later in life with few offspring, with long life spans. offspring are large, and usually require parental care. they are competitive species. |
indicator species | provide warning of damage to a community or ecosystem. examples: fish, birds, butterflies, amphibians (read more on 93-95) |
keystone species | have a huge effect on the abundance of other species in an ecosystem...remove them and an ecosystem can collapse. ex) pollinators, top predators |
a species that shapes communities by creating and enhancing their habitats to benefit other species | foundation species ex)alligators, elephants, beavers |
non-native species are often successful because | usually have no natural predators,competitors, parasites or pathogens in new niche to control their population size |