secondary production
DESCRIPTION
Secondary Production. Jimmy Nelson SES Fall 2012. SECONDARY PRODUCTION. WHAT IS IT? WHAT INFLUENCES IT? WHAT DETERMINES PATTERNS OF ENERGY FLOW THROUGH SECONDARY PRODUCERS AND THUS THROUGH ECOSYSTEMS? HOW IS SECONDARY PRODUCTION MEASURED? . SECONDARY PRODUCTION. - PowerPoint PPT PresentationTRANSCRIPT
Secondary Production
Jimmy NelsonSES Fall 2012
SECONDARY PRODUCTION WHAT IS IT? WHAT INFLUENCES IT? WHAT DETERMINES PATTERNS OF
ENERGY FLOW THROUGH SECONDARY PRODUCERS AND THUS THROUGH ECOSYSTEMS?
HOW IS SECONDARY PRODUCTION MEASURED?
SECONDARY PRODUCTION
Secondary production is the generation of biomass by HETEROTROPHS (anything that is not a plant) over an interval of time.
Secondary production is typically measured in grams of organic matter or units of organic matter (e.g. C,N,S). Also measured in energy (Kcal).
The transfer of primary production to secondary production is a very “leaky” process.
Energy removed from lower trophic level
Energy Consumed (Gross Intake)
Energy not used
Digested Energy
Egested Energy
Assimilated Energy
Urinary waste
Production:Growth and Reproduction
Maintenance: Respiration and activity
Energy Transfer is NOT 100%
Big Fish Eat the Little Fish
THE CONCEPTOF TROPHIC LEVELS
1
TROPHIC LEVEL
2
3
4
LINDEMAN 1942
0
The thinking Was
Organization By Traits
FOOD WEBS
Ocean Grassland1
2
3
4
3
ENERGY FLOW IN CEDAR LAKE BOGLINDEMAN 1942
TROPHIC LEVEL
NET PRODUC
-TION
PRODUCTION CONSUMED BY NEXT LEVELCONSUMERS
PRIMARY PRODUCER
879
148
PRIMARY CONSUMER
104
31
SECONDARY CONSUMERS
13
0
UNITS ARE KCAL/M2/YR
TROPHIC PYRAMID CONCEPT
ENERGY LOSS UP THE FOOD CHAIN
BIG THINGS EAT LITTLER THINGS
+ =
Trophic pyramids
Consequence of: Energy loss as you go up food webLarger animals tend to eat smaller animals
WHITTAKER ECOLOGICAL MONOGRAPHS 31:157 (1961) Experimental ponds
TROPHIC PYRAMIDS
5001
0.01
40,000410
1
1632
1
210
3
Primary producers
Primary consumer - Herbivores
Secondary Consumers Carnivores Detritivores
BIOMASS PYRAMIDS g Carbon per m2
Grassland(Odum 1957)
Forest(Golley 1960)
Terrestrial Aquatic
Ocean(Riley 1956)
Lake(Ravera 1969)
What limits food webs? 1st Law of Thermodynamics
You can’t get out more energy than you put in
Fixed by plants
2nd Law of ThermodynamicsYou can’t breakeven - energy is lost with
every transaction
PROCESSING CONSUMED ENERGY
Egestion
WHAT DOES AN INDIVIDUAL DO WITH ENERGY?
eges
tion
NET PRODUCTION
Community
INDIVIDUAL: ASSIMILATION EFFICIENCYCARNIVORES
DETRITIVORES
VARIES WITH FOOD QUALITY
• C:N RATIO
• PROTIEN & LIPID CONTENT
ASSIMILATION EFFICIENCY (%)
0-20 20-40 40-60 60-80 80 -100
NUMBER
OF
CONSUMER
S
50302010 0
50302010 0
50302010 0
HERBIVORES
FROM VALIELA 1995
Single cells
INDIVIDUAL: NET PRODUCTION EFFICIENCYVARIES WITH
• TROPHIC LEVEL• METABOLISM• LIFE-STYLE• QUALITY OF
FOOD SOURCE
FROM VALIELA 1995
CARNIVORES 20
10
0
HERBIVORES 20
10
0
20
10
0
DETRITIVORES
0-20 20-40 40-60 60-80 80 -100
PRODUCTION EFFICIENCY (%)1
NUMBER OF
CONSUMERS
MAMMALS & BIRDS 1 - 3 %
FISH & REPTILES 10%
ZOOPLANKTON &INSECTS
40%
Single cells
1Based on growth
HOW MUCH OF THE NET PRODUCTION OF ONE LEVEL IS INGESTED (eaten) BY THE NEXT LEVEL
TROPHICLEVEL
NETPRODUC
-TION
PRODUCTIONINGESTED (eaten) BY
NEXTLEVELCONSUMERS
PRIMARYPRODUCER
879 148
PRIMARYCONSUMER
104 31
SECONDARYCONSUMERS
13 0
UNITS ARE KCAL/M2/YR LINDEMAN 1942
(148/879)*100 = 18 %
ENERGY FLOW IN CEDAR LAKE BOG
ECOSYSTEM: EXPLOITATION EFFICIENCY
EXPLOITATION EFFICIENCY
COMMUNITY PRIMARYPRODUCERS
EXPLOITATIONHERBIVORES
(%)
MATUREDECIDOUSFOREST
TREES & SHRUBS
LARGE AMOUNT OFNONPHOTOSYNTHETICSTRUCTURE
LOW TURNOVER RATE
1 - 3
GRASS -LANDS
HERBACEOUS PLANTS
MODERATESTRUCTURALMATERIAL
MEDIUM TURNOVERRATE
10 - 40
AQUATICOcean or lake
PHYTOPLANKTON
LOW STRUCTURE
VERY HIGH TURNOVER
60 - 99
HOW MUCH OF THE NET PRODUCTION AT ONE TROPHIC LEVEL TURNS INTO NET PRODUCTION AT THE NEXT TROPHIC LEVEL
TROPHICLEVEL
NETPRODUC
-TION
PRODUCTIONCONSUMED BY NEXTLEVELCONSUMERS
PRIMARYPRODUCER
879 148
PRIMARYCONSUMER
104 31
SECONDARYCONSUMERS
13 0
UNITS ARE KCAL/M2/YR LINDEMAN 1942
(13/104)*100=
13 %
ENERGY FLOW IN CEDAR LAKE BOG
ECOSYSTEM: ECOLOGICAL EFFICIENCY
ECOLOGICAL EFFICIENCY = TROPHIC LEVEL = FOOD CHAIN EFFICIENCY
Pauley and Christensen Nature 1995
40
30
20
10
0 2 6 10 14 16 20 24ECOLOGICAL EFFICIENCY (%)
for animals that eat other animals (trophic levels 2 - 6)
N
UM
BE
R
~ 10%
RANGES FROM 2 - 50%
Why are large carnivorous animals so rare ?
HERBIVORES
HUNTERS
MCNABB 1973
40% Exploitation Efficiency5% Growth efficiency20
10% Trophic efficiency
2
1000g C m2 year
Grassland
Gazelle
Lion
HOW DO ATTRIBUTES CHANGE AS YOU MOVE UP THE FOOD WEB?
NUMBER OF SPECIES
POPULATION SIZE REPRODUCTIVE
RATES
BODY SIZE HOME RANGE SEARCHING
ABILITY MAINTENANCE
COSTS ASSIMILATION
EFFICIENCY
PRICE 1975
GO DOWN GO UP
Annual Secondary Production
Ecosystem Type
Net Primary Production (109 metric tons C yr-1)
Animal Consumption
(%)
Net Secondary Production (106 metric tons C yr-1)
TERRESTRIAL 49 7 372 Tropical rain forest 15 7 110
Temperate evergreen forest
3 4 12
Temperate deciduous forest
4 5 19
Temperate grassland 2 10 30
AQUATIC 25 37 1376 Lake and stream 1 20 120
Open ocean 19 40 1140
Upwelling zones 0.1 35 5
Estuaries 1 15 25
BIOSPHERE 74 17 1748
IN THEORY, IT IS THE SAME AS FOR PLANTS --JUST FIGURE OUT HOW MUCH BIOMASS THEY
ACCUMULATE IN A CERTAIN AREA OVER A CERTAIN TIME.
HOW TO ESTIMATE SECONDARY PRODUCTION
How many are there?
How much did they grow? X = Net
Production
-100100300500700
WEI
GH
T O
F IN
DIV
IDU
AL
0 2 4 6 8 10YEAR
=g biomassper m2 per Year
Age or Length
NET PRODUCTION = THE BALANCE BETWEEN GAINS AND
LOSSES
FOR THE FOR THE INDIVIDUAL POPULATION
• GAINS GROWTH BIRTHS
• LOSSES EXCRETION DEATHSRESPIRATION MIGRATIONREPRODUCTION
FOR THE ECOSYSTEM
FOR EACH POPULATIONINTEGRATE OVER A POPULATION COMPRISED
OF INDIVIDUALS OF DIFFERENT SIZES AND PRODUCTION RATES.
NEED TO INTEGRATE:1. THE NUMBER OF INDIVIDUALS AT ANY
GIVEN SIZE2. GROWTH AT SIZE3. REPRODUCTION AT SIZE4. MORTALITY RATES
THEN DO IT AGAIN FOR EVERY SPECIES IN THE ECOSYSTEM
THIS CAN BE DIFFICULT BECAUSE ANIMALS HAVE "BEHAVIOR"
THEY HIDE THEY BITE
SCALING WITH BODY SIZE
ATTR
IBU
TE
WEIGHT of INDIVIDUAL (g)
METABOLISM AND INGESTION
NUMERICAL ABUNDANCE
SCALING WITH BODY SIZE
P/BRatio
Wet weight (g) of individual
(1/yr)
P/B = aW b
Log [WEIGHT of INDIVIDUAL (g)]
Log (P/B)
0.0000000001 0.0001 0.01 1 100 10,000From Banse and Moser 1980
100
10
1
0.1
P/B ratio
P:B RATIO
grams
SUMMARY WHAT IS SECONDARY PRODUCTION?
All production that isn’t by a plant. WHAT INFLUENCES IT?
1st Law of Thermo - Initial energy fixed by plants. 2nd Law Thermo - Losses during processing in the food web.
WHAT INFLUENCES PATTERNS OF ENERGY FLOW THROUGH AN ECOSYSTEM? Fundamental differences between aquatic and terrestrial
environments. Quality of food eaten Metabolism and Allocation of assimilated energy by organisms.
HOW IS SECONDARY PRODUCTION MEASURED? Essentials are the same as for plants only techniques are more
varied.
LAB TODAY
If YOU DOTHIS LAB WELL, YOU WILL GET WET, MUDDY and COLD - Bring Polar fleece, hats, towel, extra clothes.
WEAR SWIMSUITS AND BRING SNORKELING AND FISHING GEAR
Later this week . . . Tomorrow for class - calculate your
own isotope estimate
Thurs - calculate the ecological efficiencies for the beginning of lab
NPP= 100,000
Ingestion2050
Units: Kcal/m2/yr
1000 30 2
Egestion
250
50
Energy LossRespiration
RespirationMigration
RespirationMigrationCaring for youngFood search
17.5150800
200 20 20 0.5
Net Production
I NP NP NPI I
EFFICIENCY (%)
EXPLOITATION
ASSIMILATION
NET PRODUCTION
ECOLOGICAL
PRIMARY PRODUCERS
SECONDARY PRODUCERS
1° consumer 2° consumer 3° consumerHerbivores Carnivores
NPP= 100,000
Ingestion2050
Units: Kcal/m2/yr
1000 30 2
Egestion
250
50escapes
Energy LossRespiration
RespirationMigration
RespirationMigrationCaring for youngFood search
17.5150800
200 20 20 0.5
Net Production
I NP NP NPI I
EFFICIENCY (%)
EXPLOITATION
ASSIMILATION
NET PRODUCTION
ECOLOGICAL
PRIMARY PRODUCERS
SECONDARY PRODUCERS
1° consumer 2° consumer 3° consumerHerbivores Carnivores
2050/100,000 = 2.0 200/250 = 80 20/20 = 100
X 100 = %
(800+250)/2050 = 51.2 (150+20)/200 = 85 (17.5+0.5)/20 = 90
250/1050 = 23.0 20/170 = 11.7 0.5/18 = 2.7
250/100,000 = 0.2 20/250 = 8 0.5/20 = 2.5