The bark provides some great texture. I like how you've composed the hole on the "thirds" line. I wish I had some sense of scale - a familiar bug or flower perhaps - to judge the size of the subject.
Excellent photo. I love high contrast photos and bark is one of the very best subjects. Very nicly captures the subject. Focus, colors, DOF, levels ... everything is spot on and the comp is pleasing. One of this crop's best.
Excellent composition, lighting and exposure. The problem is that there is no way to know for sure how close-up it is. It could be "just" an excellent non-macro shot. But, I will assume it really is macro and vote accordingly. Good job.