8.Pioneer species such as lichen and moss inhabit an area after a major disturbance such as a volcanic eruption. Over time, other species are found in the disturbed area and the number of pioneer species decreases. Why does the number of pioneer species decrease?The amount of available sunlight is reduced. The pioneer species can no longer thrive. The area has more soil to support complex plants. The competition increases between organisms. The area is more susceptible to the wind. Seeds are captured in the pioneer plants and germinate at a higher rate. The temperature is not as extreme as it was following the disturbance. Fewer of the pioneer species reproduce.