I echo Chiroptera's post; clarification is needed.
You will search in vain in the texts and journals of any of the major schools of psychology”clinical, behaviorist, cognitive, physiological, humanistic or transpersonal”for any theory or research concerning the most basic fact of human existence: the fact of our relationship to the natural world of which we are a part.
I'm having trouble understanding what you mean. The phrase "our relationship to the natural world of which we are a part" is quite vague.
For instance, the way I'm interpreting the phrase, I can't see how you'd possibly think that (to name a few relevant ideas) Pavlovian and operant conditioning, habituation and sensitization, attentional biases, the systems involved in perception and interpretive processes involved in the integration of details into coherent whole pictures, memory, the relationships between the psychology of animals studied in behavioral studies and that of humans, and a few thousand or so similar subjects of research papers don't deal at all with "the fact of our relationship to the natural world of which we are a part". If anything, I'd be hard-pressed to think of a study that doesn't have anything to do with that. Our brains are, after all, the primary tools through which we can both perceive and affect the natural world.
It would be useful for the purpose of discussion if you could more precisely define what you mean by "the fact of our relationship to the natural world of which we are a part".