Weeds growing in a recently burned a patch of forest represent the first stage in
primary succession
secondary succession
secondary colonization
biological magnification

Secondary succession

Explanation:

Weeds growing in a recently burned patch of forest can be considered as secondary succession. This is because earlier there used to be a forest which has been recently burned.

In case of secondary succession, the species grow in an environment which once has biological species and due to some natural or man made disaster it is finished.

After sometime the species starts growing on the same place where they were present earlier is known as secondary succession.