Ecosystem, Energy Flow & Food Webs Flashcards Preview

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Flashcards in Ecosystem, Energy Flow & Food Webs Deck (21)
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1

ecosystem

all orgs living in the same geographic area juntos w/ abiotic components that affect or exchange materials w/ orgs

community + its physical environ

2

nutrient

any substance org require for normal growth, maintenance or reproduction

3

biosphere

thin zone surrounding earth where all life exists
- sum of all terrestrial & aquatic ecosystems

4

primary producer

any org that creates its own food via photosynthesis or from reduced inorganic compounds
- food source for otro species in its ecosystem
- aka autotroph

5

autotroph

any org that synthesizes reduced organic compounds from simple inorganic sources (CO2, CH4)

6

gross primary productivity (GPP)

total amount of carbon fixed by photosynthesis
- cellular respiration (55%) + growth/reproduction (45%)

7

net primary productivity (NPP)

total amount of carbon fixed by photosynthesis over a given period of time minus amount oxidized during cellular respiration
- growth/reproduction part of GPP

8

consumer

org that cannot synthesize reduced organic compounds from inorganic sources, obtain them from otro orgs
- aka heterotroph

(ie) some bacteria/archaea & all fungi and animals

9

primary consumer

herbivore; org that eats plants, algae or otro primary producers

10

secondary consumer

carnivore; org that eats herbivores

11

tertiary consumer

or that feeds on secondary consumers

12

decomposer

org that eats mainly dead organic matter
- aka detritivore

(ie) various bacteria, fungi, protists & animals

13

trophic level

feeding level in an ecosystem

14

food chain

relatively simple pathway of energy flow through a few species
- each @ diff. trophic level in an ecosystem
- includes: PP, PC, SC & decomposer
- subset of food web

15

grazing food chain

ecological network of herbivores, predators & parasites that consume them

16

decomposer food chain

ecological network of detritus

decomposers that eats detritus + predators/parasites that eat decomposers

17

primary decomposer

decomposer that consumes detritus from plants

18

food web

complex interaction network among species in an ecosystem formed by energy & nutrient transfer
- consists of many food chains

19

biomagnification

increase in molecules conc. @ higher levels in a food chain
- higher orgs not able to metabolize or excrete molecule

(ie) DDT spray on crops affect birds

20

trophic cascade

series of changes in species abundance in a food web
- caused by addition/removal of a key predator

(ie) wolf removal from ecosystem effects

21

top-down control

hypothesis that population size is limited by predators or herbivores (consumers)
- removal of top predators = widespread/unexpected effects on species abundance of a community