Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Why should plants be included in investigations about the water cycle?
Plants are part of the water cycle through the process of transpiration.
Plants play a crucial role in the water cycle by absorbing water through their roots and releasing it back into the atmosphere through transpiration.