Lesson 4 – Building your Pond
A. Duckweed info Scientific Name: Lemna minor Small Light green Free-floating Seed bearing Found in ponds near or in wooded areas (freshwater) Spread mainly by ducks and geese, sometimes humans
B. Nutrients Live in nutrient-rich ponds Leaf litter for nutrients Areas with septic drainage or feed lots Nitrogen and Phosphorus are main nutrients
C. Duckweed Leaves Known as “FRONDS” Average 1-3 leaves per Lemna Length: 1/16 – 1/8 of inch Single root from each frond
D. Duckweed Overpopulation Thick growths Completely cover ponds Prevents sunlight reaching water which depletes oxygen Algae and underwater plants cannot photosynthesize Fish population decreases and dies off
E. Interesting Facts Eaten by Waterfowls (geese, swans, ducks) Eaten by humans in Thailand Shelter for bullfrogs Helps purify water Decreases water evaporation – keeps water cool
Page 46 – warm-up question Fish Ducks Algae Bacteria Frogs Dragonflies Lilypads moss