Answer:
The correct answer is - The area has more soil to support complex plants. The competition decreases the pioneer species role.
Explanation:
Pioneer species are the initial species of organisms such as lichens and moss. These species appears in disturbed land where they break the rocks and at that time of their introduction to the area, there is enough amount of nutrition for their growth and survival.
After establishing the complex plant species these pioneer species are decreased due to the competition for the resources but due to enough soil and complex structure of the new plant species, they get very few minerals and other nutrition.