Patrick, it seems you have no sensitivity whatsoever for symbolic language, for metaphor, allusion, myth. There is truth to these things, but not of the type that is susceptible to empirical tests. Which would suggest to you that such things as dryads do not exist -- and yet they do, in the conscious experience of intelligent human subjects. The important thing to note in your example is the relationship between the dryad and the tree. This is an attempt to articulate something about the nature of the life of the tree -- in symbolic language.
In short, if there is no objectively verifiable evidence for dryads, then how did you and I ever come to hear of them in the first place? The evidence is obviously there. It just isn't of a sort that science can have anything to do with. This is a matter for the "other" knowledge domain -- philosophy, cosmology, the arts, psychology, at al. -- the "sciences of the spirit."
However, I do not see any analogy between dryads and fields. If anything, the existence of fields seems to have been fairly well validated by science; e.g., quantum field theory. So, where's the dryad in what I wrote?
This opens up a big subject, and I don't know if in this first effort I'll explain myself sufficiently, but I'll try. The ancients, when looking at the world which they didn't comprehend, assigned gods to virtually everything. Humans didn't understand things, but gods did. Humans couldn't affect anything, but gods could. Just about everything had a god. Including trees, which had their dryads.
Clarification note: The Hebrews, by sweeping all that away and positing only one God, made an almost unbelievable intellectual leap. But that's not at all what I'm discussing here, and in rejecting the primitive notion of dryads (as did the Hebrews) we are not rejecting theism.These days we know -- at least we think we know -- that the existence of X doesn't necessarily imply a "god of X." We could describe the worldview of the ancients as a kind of quantum dualism -- a temporary term because at the moment I can't think of another. In the quantum dualist worldview, for each discrete object we observe there is both (1) the physically real thing, plus (2) the inevitable "god associated with that physically real thing."
Another clarification note: No, I'm not describing Platonic forms; I'm attempting to describe a worldview that's far more primitive.Science, in its methodology (and not necessarily in its philosophy) doesn't follow the ancient quantum dualism. Science proceeds to seek answers that do not employ the automatic assumption of quantum dualism. Often they succeed. When they don't, the default conclusion isn't the ancient dualism. If it were, they'd be proclaiming the intellectual equivalent of dryads.