flux of energy and matter

Question 1

who laid the foundations of ecological energetics

Answer 1

linemann 1943
attempted to quantify webs by considering the efficeny of energy transfer between trophic levels

Question 2

define standing crop of biomass

Answer 2

the bodies of living organisms in the area

Question 3

define biomass

Answer 3

the mass or organsims per unit of ground or volume of water

Question 4

define primary productivity

Answer 4

the rate at which biomass is produced by photosynthetic organisms

Question 5

define gross primary proudctivity

Answer 5

the total enegry fixation

Question 6

what is net primary productivity

Answer 6

GPP-autotrophic respiration

Question 7

what limits productivity in oceans

Answer 7

a shortage of nutrients, high porductivity is often observed when there is upwelling of nutrient rich waters

Question 8

what are the required resources for primary production

Answer 8

sunlight, co2, water and soil nutrients

Question 9

how does temperature act as a limiting factor for productvity

Answer 9

has a strong influence on photosynthetic rates

Question 10

how is temp and precipitation linked

Answer 10

high temps are associated with high evapotranspiration

Question 11

how can soil texture be a limting factor

Answer 11

coarse soils are associated with lower nutrient retention
sandy soils are lower in nitrogen

Question 12

what is primary productivity most frequently limited by

Answer 12

light and nutrient availability

Question 13

why is productivity high in euphotic zones

Answer 13

there is a high nutrient input and waters are clear allowing light to pentrate

Question 14

why are areas of ocean closer to land and outershelf less productive

Answer 14

increased turbidity closer to land
less nutrients in the outer shelf

Question 15

how does an ocean upwelling occur

Answer 15

• wind is parallel to the coast
• water is moved offshore and is replaced with cooler nutrent rich water from the bottom
• due to this phytoplankton bloom which supports the food chain

Question 16

why is iron a limiting factor in marine environments

Answer 16

it is insoluable and dervied from wind blown matter

Question 17

how can the insertion of iron into marine envrio reduce co2

Answer 17

increasing iron can cause phytoplankton blooms which take in co2 from atmosphere

Question 18

what is secondary productivty

Answer 18

the rate of production of new biomass by heterotrophic organisms

Question 19

why is energy lost through trophic levels

Answer 19

• not all plant biomass is consumed
• not all eaten is assmilated into biomass
• excretion

Question 20

what is biogeochemistry

Answer 20

the study of the fluxes of elements between living and non living compartments

Question 21

what happens if inputs are greater than outputs

Answer 21

then nutrients will accumulate in lving biomass and dead organic matter

Question 22

give some examples of inputs in a nutirent budget

Answer 22

minerals from weathering of rock and soil
atmospheric co2 and nitrogen
minerals in wetfall
human activites

Question 23

give some examples of outputs in a nutrient budget

Answer 23

• co2 in respiration or forest fire
  methan from bacterial activity in anaerobic conditions
  most dissolved plant nutrients
  dead organic matter

Question 24

where do aquatic systems recieve most their nutrients

Answer 24

stream inflow
in lakes accumulation in sediments is a major export pathway