However, specific principles differ for each species. Defense is a general principle, but the specific ways animals defend themselves is different from the specific ways trees defend themselves. Another example is that all living organisms require an energy source. This is a general principle of life. Humans must get food already made, while trees make their own.
Trees can store energy reserves only in living cells.
The major problem that has followed tree cultivation from its beginning has been the confusion of the general principles of life with the specific principles of life for trees, or worse yet, with the specific principles of life for humans. And, this has been so, because until very recently, little attention was given to tree biology, and especially tree anatomy. Anatomy must come before physiology. Tree anatomy has been a problem because trees are so massive. Bits and pieces of trees have been studied in the laboratory , but entire trees have seldom been dissected.