Saleen did not try to dodge it. Even though he was travelling at a high speed, he was fortunately under the protection of the water shield so he would not be injured even if he crashed into a mountain. He manipulated the air flow such that he slid past the giant fossilized tree just before he came into contact with it. That slide came about so naturally and was so instinctive that it was just like how a grand swordmaster controlled their sword aura.
Saleen was completely at ease. He was not as nervous as he had once been whenever he faced a crisis. He could clearly see that the other fossilized branches had been broken to pieces and there were tentacles coming out from them, attempting to grab him.