EXAM 2 - Biogeochemical Cycles Flashcards
Water enters the atmosphere through the process of?
Transpiration
Carbon enters the atmosphere as carbon dioxide when..?
- soil micro-organisms respire
- plants respire
- sedimentary rocks are uplifted and eroded
- humans burn fossil fuels
The major pool of phosphorus is located in:
Rocks
Nitrogen-fixing bacteria convert nitrogen gas to:
NH4+
nitrate
Humans have altered the phosphorus cycle by?
- fertilization of crops
- mining
- detergents
In the Western US, which forest types are present?
Coastal and interior
Forests account for how much % of land in the US? and how much % tree cover is considered forestland?
33%, 10%
Biogeochemical Cycles include what?
nonliving components and living organisms.
Define biogeochemical cycles
how chemicals cycle through biotic and abiotic portions of our environment
Describe the steps of the water cycle
- water ENTERS atmosphere w evaporation and transpiration from leaves.
- it condenses and falls from the sky as PRECIPITATION; runs off land into streams, rivers, lakes, and ocean
- Water infiltrated into AQUIFERS, becoming GROUNDWATER
TOTAL SEVEN STAGES:
evaporation, condensation, precipitation, sublimation (ice), transpiration, runoff, and infiltration.
What are GDE’s?
Groundwater Dependent Ecosystems (common in Nevada!)
What types of GDE (Groundwater Dependent Ecosystems) are there?
- pheatophytes (groundwater to surface)
- wetlands
- springs
- lakes and playas
- rivers and streams
Human impacts on the hydrologic (water) cycle?
- dams - increased evaporation
- altered surface - increased runoff and erosion
- groundwater depletion
- agriculture use - water depletion and increased evaporation
- removing forests - decreased transpiration
- atmospheric pollution - altered precipitation
the carbon cycle circulates what?
a vital organic nutrient (CO2 etc)
what do producers use from the air in photosynthesis?
CO2
consumers eat?
producers
how does CO2 return to the air?
by RESPIRATION
how is carbon stored in the carbon cycle?
- decomposed organisms and underground pressure from SEDIMENTARY ROCK and fossil fuels
- buried carbon returns to air when rocks are uplifted and eroded
how is buried carbon returned to the air?
buried carbon in sedimentary rock and fossil fuels return to air when rocks are UPLIFTED AND ERODED
carbon is mostly stored where?
carbon is stored in rock OR used by aquatic plants
ocean water absorbs what in the carbon cycle?
carbon
what is the human impact on the carbon cycle?
- more CO2 in atmosphere from BURNING FOSSIL FUELS and DEFORESTATION
- excess CO2 drives global warming and climate change
what are the largest reservoirs (in order) of the NITROGEN CYCLE?
- atmosphere
- ocean
- soils
what do specialized bacteria in the nitrogen cycle do?
they convert gaseous NITROGEN from the air into WATER SOLUBLE forms that plants can UTILIZE.
