Nutrient cycling and prokaryotes

What are some key differences of archaea from bacteria

lipids in plasma membrane are different. Highly variable cell walls, lack of PG

What are the 2 families of archaea?

Euryarchaeota - wide range of habitats - methanogens and halophiles
Thaumarchaeota - Ammonia oxidizing archaea

what are methanotrophs?

microbes that oxidize methane CH4 to CO2

Methane produced in marine sediemnts is oxidized by which methantoph

anaerobic methane-oxidizing archaeon

How much methane annually produced by methanogenic archaea?

1 billion

How do sulphur dependent thermophiles work?

use sulphur as an electron acceptor or donor - these are hyperthermophiles and they ar found in hot springs - grow best above 85 degrees

AOA (ammonia oxidizing) are found where?

agricultural soils

what cycles are AOA important in?

carbon and nitrogen

what is AOA’s role in carbon cycling? and in Nitrogen?

CO2 fixation
ammonia oxidation to form N2O

How much organic carbon production in the ocean is due to microbial autotrophy?

all

In streams and lakes what are the sources of organic carbon?

macroscopic algae and terrestrial runoff

what type of microbe can withstand changes in salinity?

Halotolerent

What open ocean organism grown in the photic zone is very important to marine life

phytoplankton - major source of organic matter in open ocean
picoplankton - extremely small plankton under 2um includes bacteria, archaea and cyanobacteria

what makes up the major amount of biomass for microbes in open ocean?

Bacteria and archaea

what makes up the abundance of microbes in open ocean

viruses

Where is the largest microbial biomass found?

under the sea in deep ocean sediments

How much of earths water isn’t saline?

3.9%

How are soils broken up into many microhabitats

different areas created by roots and other chemical/biological factors, soil particles, pore spaces.

What archaea are found in soil?

AOA’s - usually in nitrogen rich soils

define epiphytes

microbes that live on the surface of plants

define endophyte

microbes that colonize internal plant tissue

what is the rhizosphere

region of soil around a root - bacterial and fungal populations up to 100X greater than in surrounding bulk soil

what is the roles of microbes in the rhizosphere

provide nutrients, promote plant growth, and nitrogen fixation

difference between endomycorrhyzae and ectomycorrhyzae?

endo grows indie of the plant root cells, exo stays outside the cells

What are arbuscules?

branched hyphal structures formed inside of plant cells - provide nutrients to plants (can take up nitrate and annomium —→ transfer to host plant)

What is a nitrogen fixing bacteria in the soil?

Rhizobia (a-proteobacterial) turns N2 —→ ammonia NH3
often form nodules with legumes

define bacteriod

nitrogen fixing form of Rhizobia

define symbiosome

a bacteroid enclosed by a plant membrane

root nodule?

structure containing many symbiosomes

what is leghemoglobin

oxygen carrying protein that protects nitrogenase by regulating oxygen levels

What effects do photons transformed into heat have?

heat energy warms the air, surface of the land, and waters - this drives the water cycle and wind and water currents

what can a photosynthetic organism transform light energy into?

Chemical bond energy - stored in carbon based compounds

what are the 2 forms of energy?

potential - stored - available for preforming work
kinetic - energy of motion - preforms work

first law thermodynamics

energy is not vreated of destroyed

What is the second law of thermodynamics?

when energy is trransferred entropy increases
when energy is transferred from one organism to another as food
-some is stored in living tissue
some is lost as heat
entropy will increase

what type of system does second law thermodynamics refer to?

closed

in realty what are ecological systems?

open

why are ecological systems open systems?

constant input of energy from the sun

what is primary productivity?

the rate at which autotrophs convert carbon dioxide into organic compounds

What is a chemoautotrophs

convert energy from chemical compounds - eg nitrosomonas europea, or thiobaccilus hydrothermalis

where to photoautotrophs get their energy?

sunlight

what is GPP?

gross primary productivity - total rate of photosynthethis by autotrophs

what is NPP

the rate of energy storage as organic molecules after energy is expended for cellular respiration (R)

what is the NPP equation?

NPP=GPP - R

what units is this expressed in?

Kcal/m2/yr

what is the most common estimation method in aquatic systems?

Light/Dark bottle method - oxygen production/consumption is measured

light bottles

- water sampling containing autotrophs - if photosynthethis exceeds repiration, dissolved oxygen will accumulate (NPP estimate)

Dark bottles

same samlpe incubated for same amount of time as light bottle - no photosynthethis onlt repiration, so dissolved oxygen declines estimates R

What is the equation for this

O2 produced by synthethis - O2 consumed by respiration = GPP

How does percipitation influence NPP

phtotosynthethis requires stomata opening - loss of water for plant - water is replaced via roots - more water available for transpiration = more photosynthethis

water limits?

rate of photosynthethis - leaf growth

what is evapotraspiration a good predictor of?

primary productivity accross broad geographic regions

the general pattern for NPP and soil nutrient availability is?

more soil nutreints available = more NPP

define liebigs law of minimum

the resource in scarcest availability limits all growth and NPP

what is PAR

photosynthetically active radiation

what does PAR refer to

aquatic ecosystem light availability

Where is photosynthethic rate and GPP of phytoplankton highest

intermediate levels of PAR

what is compensation depth

the depth at which GPP = R and NPP=0

In oceans where are the highest levels of productivity? lowest?

coastal region, open ocean

why are coastal regions more nutrient dense

greater transport of sediments from bottom to ruface due to wave action and tides , coastal waters also recieve nutrients from terrestrial ecosystems via streamd and rivers

what are constraints on NPP in freshwater ecosystem

solar radiation limits NPP in lake ecosystem (light and temp)
nutrient availability (NPP increaes with phospherous intake)

what is the david schindler experiment?

addition of phospherous to one side of the lake increased NPP and algal growth by a lot

at what time of year is light limiting to a stream

summer- greater canopy cover

What is most limiting to stream ecosystem in fall and spring?

nutrients - as canopy opens up ther eis more light

Autochthonous?

organic carbon produced within an ecocsystem (photosynthethis)

Allochthonous

organic carbon produced outside of an ecosystem

what is DOM what is POM

Dom is dissolved organic matter and POM is particulate organic matter

Plant growth is a

positive feedback system

what is RNPP

the relative amount of net primary productivity - the relative amount of new growth compared to already standing biomass

why would grass have a higher RNPP than trees

grasses have higher relative growth rate

why is it hard to measure marine NPP

phytoplankton have short lifspans and there are many generation within annual NPP

what is annual NPP-RNPP in open oceans

42.3g/g/yr

RNPP is higher in marine ecosystems or terrestrial?

marine

what happens to NPP in cold or dry conditions

little or none as plants go dormant in winters, or dry seasons

what plant ttpe can cause NPP to vary with age?

woody plants and trees with long life spans

how to measure leaf area index or LAI

direct method through leafscans or indirect via hemispheric photography

what eventually happens to almost all primary production?

eaten by herbivores or detritivores

what happens to the consumed energy?

passes from the body as waste or assimilated for metabolism and heat and growth ofnew tissue

what is secondary production

the net energy allocated to production - the formation of living heterotroph biomass over a period of time

what is bottom up control?

NPP has a direct effect on secondary production through energy flow, populations of productive autotrophs control populations of heterotrophs

what is the “world is green” proposition?

plant biomass accumulates because predators keep herbivore populations in check

what are patterns of NPP effected by?

abiotic conditions and predator controls on herbivore population

what is I A W R and P

I - ingested food by consumer
A- assimilated food ingested
W - expelled waste
R- respiration
P- production

what is assimilation effeciency

A/I - the effeciency of extracting energy from food

what is production effeciency?

P/A - how effecient assimilated energy is used in secondary production

what are the 2 food chains

grazing and detritivore

what is the energy source for the grazing food chain?

NPP - living plant biomass

What is the energy source for the detrital food chain?

source of energy for decomposers is dead organic material or detritus

why is the detritial food chain not unidirectional?

dad organic waste from each level returns as inputs to the base of the chain

at high levels what happens to carnivores in these food chains?

can feed on herbivores from both food chains

why do stream and river ecosystems have low NPP

the grazing chain is minor - the detrital food chain is used more

what is the general rule of thumb for how much biomass in a trophic level gets converted to the next level

10%

what is the consequence of the decreasing energy transfer between trophic levels

decreasing standing biomass at each trophic level (pyramid shaped)