lecture 25

Question 1

ecosystem concept is interested in

Answer 1

how community biological structure was influenced by interactions with physical surroundings

Question 2

first ecosystem concept: (clements 1920’s)

Answer 2

ECOSYSTEMS ARE SUPERORGANISMS where each organ system (species) will not describe how the body (community) functions (not a collection of independantly functioning populations)

Question 3

second ecosystem concept (gleason 1920s)

Answer 3

ECOSYSTEMS DONT FUNCTION LIKE ORGANISM where species interact but presence/absence of any one species is independant (communities are chance associations of species)

Question 4

third ecosystem concept (elton 1927)

Answer 4

ECOSYSTEMS ARE STRUCTURED BY FEEDING RELATIONSHIPS (CHAINS AND WEBS)

Question 5

fourth ecosystem concept (lotka, 1925)

Answer 5

ECOSYSTEMS ARE NRG-TRANSFORMING SYSTEMS (equations for communities as thermodynamic systems)

Question 6

fifth ecosystem concept (lindeman 1945)

what did he develop

Answer 6

TOPHIC-DYNAMIC CONCEPT integrated webs, chains, thermo principles=transfer of energy and nutrients

pyramid of energy, trophic level description

Question 7

what is a trophic level

Answer 7

steps comprising a food chain

Question 8

which ecosystem concept is the most realistic

Answer 8

5th-lindeman

TROPHIC/DYNAMIC CONCEPT

Question 9

current ecosystem definition

Answer 9

ALL INTERACTING PARTS OF THE PHYSICAL/BIOLOGICAL WORLD act as a single interactive system (are not independant of eachother)

Question 10

an ecosystem includes

Answer 10

living (biotic)=species composition and species interactions

nonliving(abiotic)=soil/water/air/light/inorganic nutrients

Question 11

ecosystem functioning is governed by processes that result in:

Answer 11

transfer and internal cycling of nutrients and energy

Question 12

key process of an ecosystem

Answer 12

energy from sun drives transformation of inorganic carbon into organic carbon compounds by plants during photosynthesis making energy which travel up food chain through feeding relationship

Question 13

energy is stored where in a mlcl

Answer 13

in chemical bonds of organic cmpnds

Question 14

are ecosystems open or closed systmes

Answer 14

OPEN

Question 15

inputs and outputs of nutrients

Answer 15

exist but usually nutrients are recycled within ecosystem

Question 16

inputs and outputs of nrg

Answer 16

input from sun and leaves as heat (output)

Question 17

ecosystem energy exists in two forms

Answer 17

potential energy=stored nrg in mlclr bonds

kinetic energy=expended (as heat) nrg

Question 18

what governs expenditure and storage of nrg within ecosystems

Answer 18

the 2 laws of thermodynamics

Question 19

first law of thermo

Answer 19

AMOUNT OF ENERGY IS CONSTANT (IN A CLOSED SYSTEM)

Question 20

energy cannot be created or destroyed but it can

Answer 20

change form in a system

Question 21

second law of thermodynamics

Answer 21

when nrg is transformed, some energy becomes unavailable for further use

Question 22

nrg from the sun is used inpromary producers to create

Answer 22

chemical bonds in carbon-based compounds

Question 23

after nrg transfers from one organism to another–> some is ____ but most ____

Answer 23

stored

dissipates as heat

Question 24

in a closed system over time, the energy in unusable form (increases/decreases??)

Answer 24

increases

Question 25

are ecosystems closed or open systems

Answer 25

open systems

Question 26

primary production

Answer 26

the rate at white plant tissue (organic matter) is created during photosynthesis

Question 27

how to plant species vary

Answer 27

in their rate of photosynthesis or efficiency to transform energy from the sun into plant tissue

Question 28

photosynthetic rates are influenced by

Answer 28

1-quantity of above and below ground tissue 2-leaf morphology 3-modified photosynthetic pathways to increase water-use efficiency 4-adaptations to low light or high light (shade in/tolerance)

Question 29

secondary production refers to

Answer 29

efficiency of consumers to transform energy consumed into growth and offspring

Question 30

total energy consumed/ingested in the form of plant material flows through each individual consumer:

Answer 30

some assimilated through gut wall (A) some expelled as waste (W) which is NRG for others like decomposers

Question 31

out of all assimilated energy (A)

Answer 31

portion is used in respiration (R) some lost as heat as energy is used remaining is used in growth and reproduction (P)

Question 32

production energy

Answer 32

efficiency of consumer species to transform energy consumed into secondary production (P/A)

Question 33

inverts or verts (higher P/A)?

Answer 33

inverts

Question 34

ectotherms or endotherms

Answer 34

ectotherms

Question 35

carnivores or herbivores

Answer 35

carnivores

Question 36

trophic efficiency

Answer 36

relationship btwn energy produced at a trophic level (Pn) that is available for use at the next higher trophic level (Pn+1)=Pn+1/Pn

Question 37

general pattern of trophic efficiency

Answer 37

energy quantity available for use by a trophic level decreases with each successive level in the food chain due to production efficiencies (law 2)

Question 38

ecological role of trophic efficiency

Answer 38

10% of the energy stored as biomass within a given trophic level is converted to biomass at the next higher trophic level (10% rule)

Question 39

result of trophic efficiency

Answer 39

decrease in biomass of organisms within each successive trophic level (pyramid of biomass)