A. On the basis of moisture conditions of the place

1. Xerach succession: The succession initiated in extremely dry situations such as bare rock, wind blown sand, etc. The different stages in this succession are called Xerosere. Xerosere may be subdivided into Lithosere which is defined as ‘Xerosere which originates on rock surface’ and Psamosere which is defined as the xerosere which originates on sand.
2. Hydrach succession: The succession beginning in water, or very wet land as in ponds, lakes, marshes, etc and the various stages ofthis succession are called ‘Hydrosere’.

B. On the basis of the presence or absence of vegetation in the place

1. Primary succession (Also called autogenic succession): The succession which takes place on sites which have previously not borne vegetation. The land slips are better sites because of the presence of original top soil mixed up in the rock pieces. The moisture retentivity of the soil is poor and the nutrient status extremely low. Under these difficult conditions, only a few species can grow. Their soils are migrated either by wind or water or both. They also start building up the true soil by adding humus through their leaf fall, improving nitrogen status by the fixation of N₂ by root nodules, arresting silt and stabilizing the soil. As they shade the ground, conditions become favorable for establishment of an undergrowth. The changed conditions replace the original colonizers which cannot regenerate in the changed conditions. As the soil conditions are very poor in the beginning, the number of species in the beginning remains small but as the condition improves, their number increases. Thus , the earlier stages of succession are easily recognized as they are generally uniform. But in the later stages, it becomes difficult to identify them. As for example, let us take a riverain succession and their stages; 1.Saccharum spontaneum----> 2. Acacia catechu, Dalbergia sissoo ---> 3.Acacia catechu, Holoptelia, Adina cordifolia, Albizia procera-------------> 4. Adina cordifolia, Bombax ceiba, Terminalia bellerica ------> 5. Adina, Terminalias, shorea robusta---> 6. Shorea robusta,
   Lagerstroemia parviflora, Terminalia, Adina cordifolia. At first, saccharam grass grows on bare land or riverain sands, i. e primary succession. As the soil starts improving, the species go on Changing, i.e., serial stage of succession. And at last, Sal (Shorea robusta forest) becomes grown and established, i.e. Climax stage of succession.
2. Secondary succession (Also called Allogenic succession): The succession which takes place on sites after the destruction of the whole or part of the original vegetation. Clearing, burning, grazing, erosion, deposition, landslide, storm, etc are allogenic factors, which factors are responsible for secondary succession. So far as the forests of this country are concerned, they are subjected to fire, grazing and other maltreatments and so, secondary succession is very important. Unfavorable factors are mostly responsible for this succession, i.e. natural or biotic. Secondary succession mostly follows retrogression or regression, which is defined as the reversion to some earlier stage of succession consequent on the introduction of an adverse factor. Retrogression stages are lower in height and more xerophytic in character. In extreme cases, eg. Fire, clearing, etc. Sometimes, the entire vegetation may be destroyed. When the causes of retrogression are removed or the area from where vegetation has been completely destroyed is left to itself, the nature starts its work again, i.e., the vegetation starts progress. This progress is called secondary succession, which does not follow the same course as the primary succession. The colonizing species of the bare areas in primary succession and secondary succession may sometimes be the same. For instance, Pinus wallichiana, Anthocephalus cadamba, etc colonize the land slips, gravel and clearings. In tropical evergreen forests, Secondary succession starts with Acrocarpus fraxinifolius, callicarpa, Trema and Macaranga. In the hills, secondary succession is often initiated by shrub growth.