Giant: The brute forces of nature; primordial power and forces; the elemental; darkness; night; winter. The giant can be beneficent or malefic, a defender or an enemy.
Pine: Uprightness; straightness; vitality; fertility; strength of character; silence; solitude; phallic. As evergreen it signifies immortality. It was thought to preserve the body from corruption, hence its use for coffins and its presence in cemeteries; it is apotropaic.
Wow - the whole thing about trees - is this what the story is reaching to express?
This is long so again I am only copying whatever could be pertinent to the grove of green trees.
Symbols of the tree are the pillar, post, notched pole, a branch, etc., all of which are often accompanied by a serpent, bird, stars, fruit and various lunar animals. Trees bearing life-foods are always sacred, such as the vine, mulberry, peach, date, almond and sesame.
Tree: The whole of manifestation; the synthesis of heaven, earth and water; dynamic life as opposed to the static life of the stone. Both an imago mundi and axis mundi, the ‘Tree in the midst’ joining the three worlds and making communication between them possible, also giving access to solar power; an omphalos; a world centre.
The tree also symbolizes the feminine principle, the nourishing, sheltering, protecting, supporting aspect of the Great Mother, the matrix and the power of the inexhaustible and fertilizing waters she controls; trees are often depicted in the style of a female figure.
Rooted in the depth of the earth, at the world centre, and in contact with the waters, the tree grows into the world of Time, adding rings to manifest its age, and its branches reach the heavens and eternity and also symbolize differentiation on the plane of manifestation.
An evergreen tree represents everlasting life, undying spirit, immortality. A deciduous tree is the world in constant renewal and regeneration, dying-to-live, resurrection, reproduction, the life principle. Both are a symbol of diversity in unity, the many branches rising from one root and returning again to unity in the potentiality of the seed of the fruit on those branches.
Symbols of the tree are the pillar, post, notched pole, a branch, etc., all of which are often accompanied by a serpent, bird, stars, fruit and various lunar animals. Trees bearing life-foods are always sacred, such as the vine, mulberry, peach, date, almond and sesame.
Celtic: Various trees are sacred: the oak, beech, hazel, ash, yew; the Druidic oak and mistletoe represent the male and female powers. Esus appears with the willow tree. The Gaulish alder and yew are sacred, as are the Irish holly and yew, and the Gaelic rowan, which also has magical powers. Kentigern, or Mungo, is associated with the tree.
Christian: As putting forth both good and evil fruits, the tree is an image of man; as renewal through Christ’s death on the cross it is resurrection. The tree of the cross was symbolically made from the wood of the Tree of Knowledge, so that salvation and life were fulfilled on the tree through which had come the Fall and death, the vanquisher vanquished. The cross is sometimes identified with the Tree in the Midst, the vertical axis of communication between heaven and earth.
Medieval Christian symbolism has a Tree of the Living and Dead, bearing good and bad fruit on opposite sides and portraying good and evil deeds, with Christ as the trunk, the unifying Tree of Life, which is also depicted as the central of the three crosses on Calvary.
Birds: Transcendence; the soul; a spirit; divine manifestation; spirits of the air; spirits of the dead; ascent to heaven; ability to communicate with gods or to enter into a higher state of consciousness; thought; imagination.
Birds frequently accompany the Hero on his quest or in slaying the dragon. Flocks of birds are magic or supernatural powers connected with gods or heroes.
Celtic: Ambivalent as both divinity and the happy otherworld, or as magic power and malevolence... Birds are also messengers of the gods.
Christian: Winged souls; the spiritual; souls in Paradise. The Christ Child is often depicted holding a bird.