Ch 25. Carbon Cycle & Decomposition

In terms of carbon
GPP = rate of carbon capture and fixation (__________)

photosynthesis

In terms of carbon
NPP = rate of carbon assimilation into producer biomass (___- ___)

GPP - R

Carbon is considered the “_____ ____ __ ____”; Found in amino acids, DNA, glucose, coal, CO2, methane, plastics, etc.

Building block of life

Name a few major carbon pools

Oceans
Fossil fuels
Soil
atmosphere
vegetation

Put the 6 types of carbon cycle transformations in order from CO2 in the atmosphere (atmospheric CO2 = major pool) back into the atmosphere

(Out of order)
Exchange/diffusion
Extraction
Respiration
Combustion
Sedimentation/burial
Photosynthesis

Photosynthesis (atmospheric CO2 —> plant energy)
Respiration (plant energy —> plant biomass)
Sedimentation/burial (plant biomass —> FFs/limestone)
Exchange/diffusion (equilibrium in ocean)
Extraction (of FF’s (fossil fuels))
Combustion (of FF’s)

Fluxes are _____ of carbon betweem _____

movement
pools

Sedimentation/burial

Terrestrial carbon gets turned into ____ ____ over time

Aquatic carbon turns to CaCO3 in water, which then turns into ______ over time

Fossil fuels
Limestone

Exchange/diffusion is equilbrium between ______ CO2 and CO2 in ____ __ ____

atmospheric
bodies of water

Daily carbon cycle pattern
Highest CO2 is in the ____, lowest in the ____

night
day

Seasonal carbon cycling pattern
Peak productivity is in the summer, meaning CO2 is ___ in summer

CO2 is _____ in winter

lowest

highest

The seasonal carbon pattern (high CO2 in winter, low CO2 in summer) is more dramatic in (terrestrial/aquatic) systems and is more dramatic in the (northern/southern) hemisphere

terrestrial
northern

Primary production and decomposition can be spatially separated, like in the aquatics.

The ___ zone is the area of primary production, while the ____ zone is the area of decomposition

photic
benthic

Decomposers turn NPP into

detritus

Decomposition will take varying ____ depending on multiple factors, like nutrient richness, decomposer activity, and cycling rates

rates

Resources with high amounts of lignin are said to be (high/low) quality

Low

Will low or high quality resources be decomposed faster?

High quality

Lignin is said to be ____, or slow to decompose

recalcitrant

Is aerobic or anaerobic decomposition faster?

Aerobic

Decomposition is most active when
(warm/cold)
(dry/moist)
(High/low) O2
(High/low) lignin content

Warm
Moist
High
Low

The stream ecosystem is said to be a (brown/green) food web

Brown

Allochthonous vs autochthonous

Carbon source that comes from outside the ecosystem
(Ex: Terrestrial leaf matter in stream ecosystem)

Allochthonous carbon source

Allochthonous vs autochthonous

Carbon source that comes from within the ecosystem
(Ex: Algae matter in stream ecosystem)

Autochthonous carbon source

Adding supplemental nutrients will cause decomposers to decompose (high/low) quality carbon much quicker

Low

How does nutrient pollution lead to altered carbon cycling in the stream ecosystem example?

Adding nutrients —> Low quality detritus decomposed faster —> decreased detrital pool stock

How does deforestation lead to altered carbon cycling in the stream ecosystem example?

Loss of detrital input (leaf matter)

How does climate change lead to altered carbon cycling in the stream ecology example?

Increased temperatures
Altered flow timing and intesnity

Human-introduced ______ ____ of decomposers can shift an area from carbon pool to carbon release, thus altering the carbon cycle through cascading effects

(ex: earthworms)

invasive species

NATURAL variability in atmospheric CO2 concentrations occur through what kind of drivers?

Volcanic eruptions
weathering of rocks
biological activity

Humans have fundamentally altered the carbon cycle by what two major ways?

Fossil fuel extraction/combustion
Land conversion/land use changes

More CO2 in seawater leads to more ____ in the water

H+ ions

The increased H+ ions in water from increased CO2 leads to ____ _____

This acidic environment causes carbonate ions to be less abundant, also known as _______ __ __ ____

ocean acidification

osteoporosis of the sea

The acidic ocean (from high CO2 → H+ ions) environment leads to more ___ ____ in the water, thus leading to greater ____ accumulation, making it a positive feedback loop

algae blooms
CO2

“____ ___”: A small change in forcing triggers a strongly nonlinear response in the internal dynamics of part of the climate system

Tipping elements

The tropics have a large carbon storage pool due to

Strong GPP input (high light, high productivity)

The arctic/boreal has a large carbon storage pool due to

Cold weather = slower decomposition, stored carbon

What is the tropics positive feedback loop in carbon as a tipping element?

Deforestation —> _____ —> _____ —> _____ —> more deforestation

Reduced GPP
Increased warming
Increased fires

What is the arctic/boreal positive feedback loop in carbon as a tipping element?

Climate warming —> _____ —> _____ —> _____ —> more warming

Thawing permafrost
Higher decomposition rates
Higher greenhouse gas production (methane)