"Tree" by Australian Aboriginal poet Kevin Gilbert, expresses an environmental or nature spirituality in which unity and wholeness accompany the understanding that we are one with such elements of nature as a tree. Gilbert uses personification to emphasize this unity: the tree and the clay address the reader with the "I" pronoun as if they are people. This stresses how much we are interconnected with nature.

The poem also expresses unity and wholeness through enjambment, which is when a thought doesn't stop at the end of the line. For example, the speaking personified voice of the tree addressing humans says "you are nothing" and breaks for a new line. Stopping here on the word "nothing" creates a sense of alienation, threat, and anxiety, as if nature is humankind's enemy, sneering at us—until the continuation of the thought in the next line is revealed: "but through me the tree." We are relieved: our unity and interconnectedness with the tree gives us life and sustenance.

The technique of repetition in the "ands" in the following line also reinforces the ideas of unity and wholeness. We humans are part of a larger spirituality:

earth and God and man
is nothing
until they fuse

Through personification, enjambment, and repetition, Gilbert supports his theme.

Kevin Gilbert’s poem titled “Tree” emphasizes such themes as unity, wholeness, and spirituality by employing a variety of different stylistic devices, including the following:

• In line 1, the poem, using the stylistic device known as personification, immediately implies a kind of pantheistic spirituality by suggesting that trees are not only alive but can communicate (“I am the tree”).
• In line 2, the poem employs the stylistic devices of assonance (repetition of the same vowel sounds) and alliteration (repetition of the same consonant sounds), thus giving the poem a sense of unity and wholeness in its sound.  Thus “lean” from line 2 uses assonance to echo “tree” from line 1, while “lean” and “land” are tied together by alliteration in line 2, as are “hard” and “hungry.”
• Line 3 uses repetition to achieve a kind of unity: two different examples of the same kind of animal (birds) are mentioned.
• In lines 5-7 unity is again implied, since three different kinds of things (“grasses vines and man”) are said to share the same “base” – that is, “clay.” The three distinct items or further unified by being listed in the same line (7), using the stylistic device known as cataloguing.
• Line 8 sums up and generalizes the meaning the preceding lines and makes such unity explicit by using the word “all.”
• Further unity is suggested quite explicitly in the metaphor of  line 9 (“I am you”), and that unity is further emphasized in lines 9-11:
  
  I am you and
  you are nothing
• but through me the tree

These lines use the devices of repetition, assonance, and balanced syntax (“I” begins line 9; “you” begins line 10) to reinforce a sense of unity.

• Unity is emphasized again by the reference to the word “one” in line 14, and that unity is reinforced by the use of the image “one living gateway.” Meanwhile, lines 13-14 allude to the Christian idea that none come to God except through Christ.  Thus an allusion adds to the poem’s overtones of spirituality.
• Unity between the speaker and the reader is emphasized throughout the poem by the speaker’s habit of using direct address to the reader, as if a bond definitely existsbetween them.
• The syntax of line 18 echoes the structures of lines 4 and 6 and thus contributes to the unity of the poem, while the explicit reference to “God” suggests the spirituality of the work.

Unity is implied again in the verb “fuse” in line 20, just as it had been implied by the word “all” in line 17, and just as it will be echoed in turn in the word “sum” in line 21.  In these ways and others, then, the poem echoes itself, as in the echo of “fuse” in line 22.