chp 31: ecology of ecosystems

number of species found in a particular area

between two species for limited resources has a negative effect on the abundance of both species; abundance of both species decreases (neither gain)

predator feeds on prey; abundance of predator increases, and abundance of prey decreases

parasite obtains nutrients from host but does not kill host; abundanance of parasite increases, and abundance of host decreases

one species benefits while the other is not harmed; abundance of one species increases, and the other is not affected (neutral)

2 species interact so that they both benefit; abundance of both species increases

some communities have one species that stabilizes the community and holds the web together

outcompeting native species, disrupting ecosystems, and causing population declines

make their own food (ex: plants); take in inorganic nutrients and an outside energy source to produce organic nutrients; producers

obtain energy by oxidizing inorganic compounds (ammonia nitrities, sulfides)

photosynthesizers, use energy of the sun

need an external source of organic nutrients; consumers

level of nourishment within a food web or chain: producers (1st lvl), herbivores (2nd lvl), carnivores (3rd 4th lvl); trophic level 1 has the most energy, as each trophic level goes up they only keep 10% of the energy from the previous lvl bc most of the energy is lost as heat

primary producer (autotroph) -> primary consumer (heterotroph) -> secondary consumer -> tertiary consumer

contains communties adapted to regional climate

the toxins in organisms get more and more concentrated as they move up the food chain

tropical rain forests, savanna, temperate grasslands, taiga, tundra, desert

on the equator, greatest amount of rainfall, high average temp

african grassland, alternating wet and dry season

receive less rainfall than temperate forest, more water than deserts

cold northern coniferous forest

north, no trees just grass and cold. soil is frozen

very little rain, hot days cold nights

climate

long-term weather patterns

niche (their own room); specific to each species; role the species plays in its community

no 2 species can occupy the same niche at the same time

fragile web of interdependencies

interconnecting paths of energy flow; multiple food chains interacting together