Explanation:
Primary succession is one of two types of biological and ecological succession of plant life, occurring in an environment in which new substrate devoid of vegetation and other organisms usually lacking soil, such as a lava flow or area left from retreated glacier, is deposited.[1] In other words, it is the gradual growth of an ecosystem over a longer period of time.[2][3]
Primary succession occurring over time. The soil depths increase with respect to the increase in decomposition of organic matter. and there is a gradual increase of species diversity in the ecosystem. The labels I-VII represent the different stages of primary succession. I-bare rocks, II-pioneers (mosses, lichen, algae, fungi), III-annual herbaceous plants, IV-perennial herbaceous plants and grasses, V-shrubs, VI-shade intolerant trees, VII-shade tolerant trees.
Primary succession on Rangitoto Island
In contrast, secondary succession occurs on substrate that previously supported vegetation before an ecological disturbance from smaller things like floods, hurricanes, tornadoes, and fires which destroyed the plant life.[4]
