In the grasslands, trees do not replace the grasses as a part of an ecological succession because of

The correct answer is water limits and fire.

Important Points

1. The trees do not replace grasses as they require more water than grasses and this would lead to water scarcity for other species.
2. Also, trees are prone to catch fire and the fire spreads swiftly. Due to these reasons, trees do not replace the grasses as a part of ecological succession.

ECOLOGICAL SUCCESSION:

1. When there is a change in the species structure of an ecological community over a period, it is called ecological succession.
2. The process continues until a stable community is formed, which is known as the climax community.
3. As the process continues the complexity of the community keeps on increasing.
4. Ecological Succession is of following two types:
   1.  Primary Succession - When the succession starts from an area that has not been previously occupied is referred to as primary succession. The pioneer species here include microorganisms, lichens, and mosses.
   2. Secondary Succession - When the process of succession occurs in an area where species existed at some point in time is referred to as secondary succession.  

• Secondary Succession is relatively rapid, as the land contains the nutrients required for the survival of species.