Sensing the destructive nature of the attack, the tree wasn't sure how many roots it would have to sacrifice to endure it. What was worse was the instinctual fear of sacrificing more of its roots just for Noah to conjure another one soon after like he did just now. Even with its plethora of roots, how many roots would it have left in the end by the time Noah was unable to generate more attacks of the same destructive capacity? Even if it were able to persist till the end, the amount of damage caused to its roots would be devastating for its future growth.
The realization of its peril drove the tree into a state of panic. The tree desperately tried to show Noah that it no longer intended to oppose him. But without the ability to "speak", the tree was only left with being able to send out its intention. Its feelings were one of intense fear and desperation. To it, the message was clear, it didn't wish to fight anymore.