Biogeochemical Cycle Flashcards
What are 4 abiotic components of an ecosystem that contribute to chemical reactions?
atmosphere
water
soil
parent material (rocks)
Define the biogeochemical cycle
the flow of nutrients between the abiotic to the biotic and back to the abiotic components of an ecosystem
What are the 2 major biogeochemical cycles? what is the third?
gaseous
sedimentary
hybrid
where are the major pools of nutrients in the gaseous cycle?
atmosphere and ocean
What scale does the gaseous cycle occur at?
global
what major nutrients have gaseous cycles?
nitrogen
CO2
oxygen
Where is the biggest pool of nitrogen?
the atmosphere
Where are the main pools of nutrients in the sedimentary cycle?
soil
rocks
minerals
How are the nutrients involved in the sedimentary cycle released from abiotic to biotic components?
through the weathering and erosion of sedimentary materials (rocks, soil, minerals)
Which element has no gaseous phase to contribute to a gaseous cycle?
phosphorous
what are the 2 phases of the sedimentary cycle?
rocks: the Earth’s crust is weathered releasing mineral salts
solution: soluble salts enter water cycle
Describe hybrid cycles
a combination of gaseous and sedimentary cycles
Which element has a hybrid cycle?
sulfur
Where are the major pools of sulfur?
earth’s crust and atmosphere
What drives gaseous and sedimentary cycles?
the flow of energy through an ecosystem - usually light, but sometimes geothermal energy
What other cycle are the gaseous and sedimentary cycles connected to? explain
the water cycle
water carries soluble nutrients and other materials throughout an ecosystem
What is an example of how the water cycle is connected to biogeochemical cycles?
Hubbard Brook
describe the basic steps involved in the BGC cycle
atmospheric input > plant tissues > retranslocation (internal cycling) > litterfall > DOM > output or decomposition and mineralization > soil nutrients also influenced by rock/mineral weathering > output or plant uptake > assimilated into plant tissues
How is decomposition/mineralization quantified?
soil litter bag experiments
How is incorporation of nutrients into plant tisuse measured?
CO2 uptake over time
ex. immobilization of C14 in Mirror Lake and filtering algae
How does the type of cycle influence how nutrients enter an ecosystem?
nutrients with a gaseous cycle enter through the atmosphere via uptake of gases or precipitation
nutrients with sedimentary cycles enter through the weathering of rocks and minerals
nutrients (S) with hybrid cycles can enter both ways
What nutrients have sedimentary cycles?
P
Ca
Mg
K
Si
What brings supplementary soil nutrients into a terrestrial ecosystem?
wet fall: rain, snow (precipitation)
dry fall: airborne particles, aerosols
What happens as precipitations fall to the forests on earth?
rain from atmosphere land on tree canopies and down stems and pick up nutrients on leaves and stems