LIFE SCIENCE

Students in a science class visit four local ecosystems. The students observed the species present in each ecosystem and recorded their observations in the table. *Ecosystem 1:Grassy lawn on school property Observation:The grass is mowed often and kept short. Two sparrows foraged for food in the grass. No other animals were observed.Ecosystem 2:Small pond with cattails growing around the edge Observations:Two types of fish were seen in the pond. Tadpoles were swimming in the shallow areas. Large wading birds were seen feeding on tadpoles and crayfish.Ecosystem 3:Agricultural field Observations:Wheat plants are the only plants growing in the field. There were many insects. No predators were observed except for a single circling hawk.Ecosystem 4:Wooded area along a stream Observation:Fish, frogs, crayfish, insect larvae, and turtles were seen in the stream, and wading birds were eating small fish. Raccoon tracks were seen in the mud. Deer were moving through the trees. Many birds were seen feeding in the canopy of the woods.Based on these observations, which ecosystem is likely to be the least sustainable.