Pls answer Use the canopy figures 4, 5 and 6 to answer the following questions:
a. Which tree species disappeared between 20 and 50 years after the field was abandoned?
b. What tree species appeared between 20 and 50 years after the field was abandoned?

**Think about the types of trees growing after 20 years in the understory. Are they tall or short species? Now think about the types of trees growing after 50 years. Are they tall or short species?

**Based on your answers to questions 3 and 4, what caused the change in the air and soil temperature between 20 and 50 years after the field was abandoned?

*Did certain species of trees decrease or disappear during succession? Discuss what factors and conditions may be related to these changes.

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.