Download Nutrient Uptake by Duckweed

Nutrient Uptake by Duckweed
• Ecosystem services are natural support
systems that humanity depends upon.
• Can you give some examples of natural
support systems (ecosystems services)?
• Why might ecosystem services be threatened
or taken for granted by humans?
Ecosystems provide “services” that:
• control agricultural pests
• maintain biodiversity
• generate and preserve soils and renew their fertility
• contribute to climate stability
• purify the air and water
• regulate disease carrying organisms
• pollinate crops and natural vegetation
• moderate weather extremes and their impacts
• disperse seeds
• mitigate drought and floods
• protect people from the sun’s harmful ultraviolet rays
• cycle and move nutrients
• protect stream and river channels and coastal shores from erosion
• detoxify and decompose wastes
• Source: Ecological Society of America, David Inouye
What ecosystem services might
wetlands provide?
What elements are found in plants?
How do they get there?
• Non mineral nutrients:
– carbon, hydrogen and oxygen
– Source: air and water
• Mineral nutrients:
– Primary macronutrients: nitrogen, phosphorus,
potassium
– Secondary macronutrients: sulfur, magnesium,
calcium
– Micronutrients: boron, copper, iron, chlorine,
manganese, molybdenum, zinc, nickel
– Source: soil, may be dissolved in water
How can nutrients be a problem in
aquatic ecosystems?
• Excess nutrients can lead
to algal blooms in water
and consequently
eutrophication.
• Excess nutrients can
result from fertilizer
runoff and animal
manure.
• Human waste is also a
source of nutrients that
need be removed from
waste water.
Source: USGS
How can plants and other organisms enhance
natural support systems to clean water?
• Bacteria are sometimes
used to clean up oil
spills. These bacteria
feed on oil.
•
Images from USGS
How can plants and other organisms enhance natural
support systems to clean water?
Bacteria feed on
organic waste in
wastewater treatment
plants.
How are the bacteria
represented in this
drawing?
Source: mub.org
How can plants and other organisms enhance
natural support systems to clean water?
• Some wastewater
treatment plants send
their effluent out
through wetlands for
more cleaning (tertiary
treatment).
Source: USGS
How can plants and other organisms enhance
natural support systems to clean water?
• Cattails have been used
to remove and
concentrate heavy
metals.
How can plants and other organisms enhance
natural support systems to clean water?
• Justin Jasper and Mi
Nguyen at UC Berkeley
study the removal of
trace pharmaceuticals
and pathogens in
human designed
treatment wetland (unit
process wetland) in
Discovery Bay.
How can plants and other organisms enhance
natural support systems to clean water?
• Niveen Ismail at
Stanford studies the
uptake of particulate
matter by clams and
mussels.
• The clam on the right
has removed algae from
the beaker it was placed
in.
Photo by Niveen Ismail
Duckweed (Lemna spp.)
Duckweed is common in
still waters
Although duckweed is a
flowering plant, it usually
reproduces asexually.
Each frond is considered a
plant even if it is still
attached to others.
Duckweed lab