Topic 2: Ecosystems

Question 1

Ecology

Answer 1

The study of interactions of organisms with their physical environment and with each other

Question 2

Abiotic

Answer 2

Non- living: temp, light, rainfall, soil chem, soil moisture, wind

Question 3

Biotic

Answer 3

Living

Question 4

Ecosystem

Answer 4

The organisms and abiotic factors interacting with each other in a given location

Question 5

Biome

Answer 5

A major ecological community characterised by a distinctive type of vegetation influenced by rainfall and temperature almost exclusively

Question 6

Food Chain

Answer 6

Producers- trap solar energy through the process of photosynthesis and provide the energy for the rest of the chain

direction of arrows up to indicate energy flow

top carnivours are dependent on the sucess of many levels

Question 7

Trophic Level

Answer 7

Organisms at a particular trophic level are the same number of energy transfers away from the original source of energy that enters the ecosystem

refers to a level on an ecological pyramid

Question 8

Producers

Answer 8

Providing energy and material to the rest of the organisms in the web/ ecosystem.
create new biomass through photosynthesis

can also act as a home to some consumers

energy source to decomposers

serve to hold nutrients in the soil and help resist soil erosion

Question 9

Consumers

Answer 9

Feeding on producersand providing food as prey to heigher level consumers

compete with eachother for food causes –> competition predetor prey relashinships mutualism or parasitism

Question 10

Decomposers

Answer 10

Reduce large organic compounds into simple inorganic compounds

break down dead matter and return various nutrients to the soils

scavengers- each whole dead organisms (decomposers, large animals)

detritovours -feed on large pieces of organic matter in the soil (small insects and invertebrates)

Saprotrophs- feed on dead or decaying matter, digest large organic molecules into simple inorganic molecules for plants (fungi and decomposers)

Question 11

Solar Energy

Answer 11

Critical to life on earth.
1) drives photosynthesis –> no usable energy for living organisms –> energy used for movement active transport, biosynthesis, growth, reproduction

2) warms up earth–> providing temperature suitable for living organisms
3) drives cycling of water and transfers of heat by wind and water –> cycle provides basis for development of ecosystems –> winds serve to circulate water and inorganic nutrients

Question 12

Photosynthesis

Answer 12

Visible light absorbed by the chlorophyll, green light reflected –> transformed into chemical energy in the form of glucose –> glucose food of producers, energy storage, building material, building proteins and fats –. chlorophyl needed to conduct transformation

inputs- solar energy carbon dioxide and water
outputs - glucose and oxygen

6CO2 + 6H2O –> C6H12O6 +6O2

Question 13

Respiration

Answer 13

6O2 + C6H12O6 –> 6CO2 + 6H2O

inputs- glucose and oxygen
outputs - carbon dioxide heat and water

mitochondria –> energy released through process form ATP –> used for movement, synthesis of large molecules, active transport and reporduction

when respiration does not occur with oxygen outputs are carbon dioxide and:
methane, ethyl alcohol, hydrogen sulfide, nitrogen gas

Question 14

Primary Productivity

Answer 14

Rate of energy capture in autotrophs

Question 15

Gross Primary Productivity

Answer 15

Plants

The total gain in energy or biomass per unit area per unit time fixed though photosynthesis (example unit g/cm^3/hour)

too hard to measure, can only be calculated by using

NPP= GPP -Respiration

Question 16

Net Primary Productivity

Answer 16

the rate at which energy is stored as biomass. represents food that is available to consumers in an ecosystem.
(example unit g/cm^3/hour)

New mass
NPP= GPP- Resp

Question 17

Secondary Production

Answer 17

energy capture by heterotrophs

Question 18

Gross Secondary Production

Answer 18

Total gain of energy or biomass by consumers per unit area, per unit time through absorption
GSP= Food Eaten - Feces
mass/ area / time
energy / area / time

Question 19

Net Secondary Production

Answer 19

new mass
food eaten - feces - respiration
Gain by consumers of energy or biomass per unit area, per unit time remaining after respiratory losses.
g/cm^3/hour

Question 20

Biomass/ Energy/ Productivity Pyramid

Answer 20

Producers–> primary consumers -> ….

Energy decreases from level to level because of second law of thermodynamics –> respiratory losses

Productivity/ energy pyramid is ALWAYS shape of a pyramid

Approx 10% of energy available to next level

Biomass is an instantaneous measure
productivity is gathered over time

Question 21

Number Pyramid

Answer 21

producers –> primary consumers –> …

Can have 1 tree, but many insects, this tree would provide lots of energy for the insects because it is so large…

Question 22

Vegetarian

Answer 22

if we ate plants, more food available for people, more people could be supported
but risk protein deficciencies, lack of particular amino aicids

Question 23

Biomagnification

Answer 23

The increase in concentration of toxic molecules from one trophic level to another.
molecules cannot be transformed by the body

Increase –> passed on, less organisms same # of toxins
heighest levels suffer first

DDT/ pestacide, kills birds in US
reduced the egg shell thickness, when falcons sat on them they would break, reproduction decreased

Question 24

Limit in Length of Food Chains

Answer 24

The cumulative decline in energy, there isn’t enough energy to support another trophic level- animals would spend more energy looking for food than gained by the food.

The efficiency of energy transfer between trophic levels.
If efficiency is high, more energy available to the next trophic level.

Total photosynthetic productivity , GPP, the base of the pyramid, can support more trophic levels.

Question 25

Top Carnivours are Rare

Answer 25

This is due to the fact that they are fully dependent on the success of the lower levels
in addition there is less energy available to them
catastrophe of any kind could wipe out their population
genetic diversity is less

rare, more valuble, more poachers

Question 26

Efficiency

Answer 26

Output/ input
Output= NPP
Input = GPP

Question 27

Compare & Contrast Aquatic and Terrestrial Food Chains

Answer 27

1) Solar energy- water absorbs energy therefore not as much reaches the plants, lower efficiency
2) Transfer of energy- more efficient in aquatic food systems because less indigestible material
3) Movement- abundancy of water supports aquatic organisms, don’t spend as much energy, spend less energy, is lost as heat, more available to next trophic level
4) Warm blooded- cold blooded animals do not loose as much heat through respiration (aquatic) more energy available to next trophic level
5) Single celled base- more reproduction, more GPP, can support more levels (aquatic)
6) Humans- aquatic feed heigher in food chain

Question 28

Measure Biomass

Answer 28

Cutting grass, random places in the ecosystem, over long period of time, dry mass, calculate year long average

instantaneous measure

Question 29

Units Flows Stocks

Answer 29

Flows- rates- energy/area/time

stock- energy/ area