biotic factors
DESCRIPTION
FACTORES BIOTICOS Y EJERCICIOSTRANSCRIPT
WHAT ARE TROPHIC LEVELS
TROPHIC LEVELS ARE THE POSITION THAT AN
ORGANISM (OR GROUP OF ORGANISMS) OCCUPIES IN
THE FOOD CHAIN
MAJOR TROPHIC LEVELS ARE PRODUCERS,CONSUMER,AND
DECOMPOSER
PRODUCERS
• 6 CO2 + 6 H2O + SOLAR ENERGY = C6H12O6+ O2
• PHOTOSYNTHESIS – COMPLEX CHEMICAL REACTION IN WHICH PRODUCER USE CHLOROPHYLL TO CONVERT CARBON DIOXIDE INTO GLUCOSE AND OXYGEN
CONSUMERS
- RESPIRATION – THE CHEMICAL REACTION IN WHICH OXYGEN AND GLUCOSE PROVIDE ENERGY FOR AN ORGANISM
C6H12O6+ O2 = 6 CO2 + 6 H2O + ENERGY
ENERGY TRANSFERS
• HEAT LOSS TO ENVIRONMENT• CONVERTED TO LIGHT• LOST BETWEEN TROPHIC LEVELS• RE-RADIATED TO ATMOSPHERE
AS ENERGY IS EXCHANGED IT IS CONVERTED BUT NOT LOST.
MEASURING GROSS PRODUCTIVITY
• THE TOTAL GAIN IN ENERGY OR BIOMASS PER UNIT TIME WHICH COULD BE THROUGH PHOTOSYNTHESIS (GPP) OR ABSORBSION IN THE CONSUMER (GP)
MEASURING PRODUCTIVITY
• GPP – THE TOTAL AMOUNT OF ENERGY GAINED THROUGH PHOTOSYNTHESIS
• GP – THE TOTAL AMOUNT OF ENERGY GAINED IN PLANT CONSUMERS
MEASURING NET PRODUCTIVITY
• THE AMOUNT OF ENERGY THAT IS AVAILABLE AFTER THE ENERGY LOSS FROM RESPIRATION
MEASURING NET PRODUCTIVITY
• IT IS THE NET PRODUCTIVY WHICH REPRESENTS THAT AMOUNT OF ENERY AVAILABLE FOR THE NEXT HIGHER TROPHIC LEVEL
DATAB. TO CALCULATIONS
• GP FOR PHYTO = 190 g/m2/yr
• RESPIRATION FOR PHYTO = 64 g/m2/yr
• PHYTO EATEN BY ZOO = 56 g/m2/yr
• ZOO FECAL LOSS = 15 g/m2/yr
• ZOO RESPIRATION LOSS = 22 g/m2/yr
CLASS EJERCISES CALCULATIONS
1-CALCULATE THE PHYTOPLANKTONS NPP
• NPP = GPP-R = 190 - 64 = 126 g/m2/yr
2-CALCULATE THE ZOOPLANKTONS GP & NP
• GP = (PHYTO EATEN ZOO)-FECAL = 41 g/m2/yr• NP = GP-R = 41-22 = 19 g/m2/yr
GENERALLY, ONLY 10% OF THE ENERGY MAKES IT FROM THE LOWER LEVEL TO THE NEXT HIGHER LEVEL
Thanks. A. C. B.
Fuente• Wikispaces.com• Encarta.com