1. Nutrient Uptake by Duckweed

2. 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?

3. 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

4. What ecosystem services might wetlands provide?

5. 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

6. 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

8. 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

9. 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

10. 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

11. How can plants and other organisms enhance natural support systems to clean water? Cattails have been used to remove and concentrate heavy metals.

12. 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.

13. 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

14. 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.

15. Duckweed lab