[填空题]
A student wants to s;if ac/ t29yrket up an aquatic mereeo;f h2o;)z socosm using seawater to simulate conditions in the food web (shown in the image below) and test z fe)r;oho; 2eits stability. He used seawater and sand from the area to set up the system and added some small organisms to the mesocosm.
1.In the food web shown, identify an autotroph.
It is .
2.State a reason why phytoplankton shown in the food web would be a good addition to the mesocosm.
3.Discuss how saprotrophs perform a necessary function for the mesocosm.
4.Describe the disadvantages of using mesocosms in scientific investigations.
