lec 13: ecosystems and carbon cycling

Question 1

ecosystem

Answer 1

a system of organisms and their physical environment

all organisms in an area + physical environment+ biotic and abiotic interactions

fundamental properties : energy flow and productivity , nutrient cycling , habitat structure

Question 2

population

Answer 2

organisms of the same species living in the same habitat
fundamental property = abundance (e.g biomass)

Question 3

community

Answer 3

coexisting populations of different species

fundamental properties = species diversity and food web structure

Question 4

autotrophs

Answer 4

self nourishers , get their own biomass ,
essential elements = K2 (atmosphere) P,S,Ca (lithosphere) +energy (solar or chemical)

Question 5

heterotrophs

Answer 5

nourished from others

Question 6

laws of thermodynamics

Answer 6

1st= conservation of matter and energy

ecosystems are transformation systems (input-ouput machines) for energy and matter