If this is your first pregnancy, you may not feel your baby move until closer to 25 weeks. By the second pregnancy, some women start to feel movements as early as 13 weeks.
exists and is an alternate of. Merge this question into. Split and merge into it. Answer by Mayra03. Confidence votes 145. A landslide or volcanic eruption is a kind of primary disturbance. It causes a very drastic and sudden change in the landscape.ecomposition is not a disturbance of the ecosystem. This is because it is a natural process in harmony with the ecosystem rather than an outside force is interfering.
Secondary succession is the succession of communities in a previously inhabited area which have been naturally or artificially disturbed. Here soil and some organisms are already present. e.g., cut over forest, abandoned crop land, ploughed fields and lands that have been flooded.oil is absent at the beginning of primary succession and the environment is not suitable for sustaining normal life forms. 3. There is no humus in the beginning as soil is absent. 4. Reproductive structures or propagules of any previous community are absent.