LE 15: Nutrient Cycling Flashcards
What are the major nutrients that cycle?
water, phosphorus, nitrogen, and carbon
How are nutrients found in terrestrial biomes?
Found in soils
- Weathering of rocks frees nutrients in the form of soil
- decomposition of matter allows for nutrients to be freed from layer of nutrient poor soil
cold environments, less precipitation = striated soil layers
hot environments, more precipitation = blended soil layers
What are cryptobiotic soil and what are they important?
Soil produced by organisms such as algae, cyanobacteria, and fungi
- release gelatinous material that binds soil particles in a dense mix = keeps nutrients together
How does erosion affect an ecosystem? Why should we not walk on the side of the cliff?
causes nutrient poor soil that cannot sustain an ecosystem
- kept by ground covering plants like grass
Plants hold the soil on the side of the cliff
- walking = erosion
How are nutrients found in aquatic biomes?
They cycle from the changes in temperatures/ upwellings
- temperate regions have the most cycling in spring and autumn (well stirred and consistent temperatures with more wind to draw up nutrient rich water)
Inputs:
- Allochothonous input: leaves and other matter falling in water
- Autochthonous inputs: produced inside ecosystem
Zones:
- Littoral: emergent plants
- Limnetic: algae
- Profundal: no sun
Where do rivers get wider and slower downstream?
where nutrients are accumulated
How do excess nutrients affect ecosystems?
excess nutrients = algal blooms and dead zones
dead zones process:
- excess nutrients = bottom up regulation
- algal growth = overshoot
- nutrients depleted = they die
- bacteria feed on algae and use oxygen
- water becomes oxygen poor
- from bacteria also from the algae decline that was making oxygen from photosynthesis
- equalizes itself out again (temporary disturbance)
Effects: algal blooms can be toxic and affect drinking water
- results in cloudy water that causes photosynthetic organisms from getting enough sunlight for photosynthesis
- agriculture contributes a lot of excess nutrients every summer
What is the water cycle driven by and how is it affected?
driven by heating and cooling of the sun: evaporation, humidity, precipitation, runs off into bodies of water, etc
- in plants = cycling of water and other nutrients too
deforestation disrupts the hydrologic cycle by resulting in more water running off
- trees absorb water = less run off and transpiration into air for cycling
- less trees = more dry = more erosion
Soil and ground holds water through aquifers (locations that holds run off water)
- ground breaks when we take more water than replenished
How does phosphorus cycle and its importance?
tied to the water cycle
- found in rocks = water runs over rocks and collects phosphorus = bioavailable nutrients that have been broken down by weathering
can be found in benthic layer
significance:
- Plants use the run off water and consumers get bioavailable phosphorus by eating plants
- used in fertilizers and cleaning products
How does nitrogen cycle?
not bioavailable in its natural form in air
Nitrogen fixation allows for plants to take it in
- eat the plants for Nitrogen
- nitrogen fixing bacteria
Decomposition allows for nitrogen to go back into the air
- decomposers (bacteria and fungi) drive decomposition
How does carbon cycle and why is it important?
tied to energy cycling
- in food we eat
process:
- plants take CO2 to make sugars that are eaten by us
- decomposers break down food = compressing into usable carbon chains
Cellular respiration and decomposition = carbon cycling
How does CO2 amounts affect heat?
more CO2 = less heat escape