Tackling Forest first:
Etymologically speaking it arises from Middle English, from Old French, from Medieval Latin forestis (silva), outside (forest), from Latin fors, outside.
In England, the Forest was an area set aside by the monarch within which to hunt. A profusion of trees is the key here, though not in the D-G sense.
The space within the Forest is permeated by the root systems of the trees. The tree is the most obvious illustration of the rhizome, in terms of its roots and branches. The tree roots hold the soil together while the branches extend to provide shelter.
It is the Emission of the rhizome, illustrated as the leaves springing forth from the branch, which fill the spaces within the rhizome of the Forest.
That is to say, movement takes place in the spaces between root systems. The ecosystem of the Forest takes place under the guardianship of the trees. The trees serve as gods of the Forest, that is, they are symbolic and immanent manifestations of the /genus loci/. Whether these be dryads, or the Green Man, the Trees serve as boundary-markers, inherently jealous of their territory - so much so that at their height, even light is impeded from entering their domain.
Within this domain, the flora and fauna are shielded and enclosed in a fashion that renders them more mysterious - that such things may exist inside the enclosure that the Trees guard so zealously infuses them with a sense of Otherness. See Tolkein's work regarding the Ents for an illustration of the function of Trees in relation to other flora and fauna.
They have a seemingly unswerving dedication to guardianship - the Trees may live centuries performing their function, a fact that dwarfs the human life-span and hints at the essential non-human nature of the forces within them, and the spaces they guard and pervade.
It is interesting to note that originally, it was only the king who was allowed to hunt in the Forest - they were essentially his to do with as he willed. See my comments on the Meatology of the Redeemer regarding the etymology of the word king.
Essentially, the king is symbolic of the Adept of Humanity. Thusly, it may be said that the king must have ties or attachment/links to all the entrances/exits to the Telluric Spheres within his own particular domain which is given to him by his people.
The Indo-European roots of Forest lie as deep as actual roots:
dwher - Door, doorway (usually in plural). Originally an ablauting noun *dhwor, *dhur-, in the plural, designating the entrance to the enclosure (*dhwor-o-) surrounding the house proper. In suffixed o-grade form *dhwor-ois (locative plural).
Thus the Trees that form the Forest to the eyes of most of humanity are in fact only the Doorkeepers to the enclosed spaces Within and Between the rhizome.
The Forest is a realm of darkness, and as such, the Fog of War within its environs is soup of Aer and Erath, with a larger proportion of Erath involved.
Thusly, WarMachines involved in Forest campaigns are essentially camouflage based, producing autonomous colonies which interact on a parasitical level with the Trees themselves. Within the spaces of the Forest, the Hunter-Seeker-Dweller War-Machine complexes use the all-pervasive root systems of the Trees to be become almost non-local in nature.
Thusly, blending with their environment, the HSD becomes a unified structure of the Forest-Space on a quantum level, able to observe/feel movement and disturbance within the Forest, accessing the totality of information within a broken tree-branch or a footprint.
The rapid dissemination of this information within a network of HSD's leads to the instantaneous transmission of information, allowing pinpointing of the prey or interloper within the space.
Examples of mythic, large-scale HSD complexes can be found in the mythology surrounding Robin Hood, Merlin, and Herne the Hunter as well as countless others.
Jungle-space is essentially similar to Forest-Space in a variety of ways except that the environment itself is inherently more hostile. If we regard Vietnam and the Rainforests of Brazil as Jungle-Space then one may see that again, Trees play a great role, in providing enclosure. As the article Reza commented on suggests, Jungle-Forest space has a tendency that bars and encloses – a place of openings and closings, irregular, organically grouped spaces within a space that is Outside – thus those who function within it ‘trust their feelings’.
Each telluric space/sphere has its own distinct method of encoding its information. The War-Machines that attempt to colonize such places must adapt, becoming /like/ the place in order to function – essentially hijacking already present mechanisms and thus becoming part of the information network of the space by digesting and integrating its protocols.
While singular Forest-Space has large-scale hostile predators in the form of wolves, bears, boars etc, so singular Jungle-Space has fewer large-scale, and more small-scale predators that are equally harmful. Poisons abound and the one who enters into this space must be able to decode the meanings and dangers within. Jungle-Space is also inhabited by Aer-Erath Fog of War though there is a higher proportion of Water than in Forest Space.
Thusly, Jungle WarMachines exist in a soup of MUD – Multiplexial Universalist Deontology, with lesser emphasis on the darkness/blinding brought about by Aer than Forest-Space. Popular Culture places the film ‘Predator’ as the epitome of maximal effectiveness within the context of the Wargasm in Jungle-Space.
The chameleonic Predator moves easily through the jungle, hunting and killing the soldiers by becoming unified with the environment. Ultimately however, it is Arnie’s covering of himself with MUD that enables him to disappear and kill the alien.
At the other extreme, Desert-Space is Empty where Jungle-Forest space is Full but both exert heavy-duty ontological pressure upon observers. Jungle-Forest Space contains a distribution of information and noise that is fairly regular, however Desert-Space is a great expanse of noise under which certain hostile hunters – that is scorpions/snakes burrow. Meaning, therefore, and resources are grouped in oases which desert inhabitants travel between in order to trade and gain complexity by sharing information and creating ‘new’ messages.
DUST being the medium of the War in the desert, those who travel within this pestilential fusion of Aer and Erath are infected by it, becoming its agents, breathing it in. Desert tactics therefore require that one operate from the network of oases in a nomadic fashion, moving under the cover of Darkness imposed. Further, if one wishes to attack in the desert proper, one must bury oneself in the sand/DUST which lies quiescent, operating /under/ the noise. Similarly, there are those who must follow the underground tunnels formed by long-dead Tree-roots within Forest-Jungle – and those who dig their own, in order to protect the Trees and the essential enclosed space – Hunter-Burrowers-Priests. Operating under the noise of the sand-leaf-litter, the burrower-hunter-killer-dwellers occupy the subtlest of positions, thus enabling them to strike from positions where the enemy/prey has no erected defence because he believes his foe to be elsewhere.
DUST is primarily a construct of Erath and Aer with very little of the Water – that which exists in the Desert-Space is found in oases or deep down by the burrowers.
There is however, a fourth telluric space. Just as Jungle and Forest make Jungle-Forest Space and its accompanying tactics, so Desert has a brother in Mountain. Mountain reaches high into the Aer, its ontological pressure both has a looming and also a penetrative quality. Upon the summit of the Mountain, that High place with roots that stretch cavernous and cave like Below, Aer facilitates blindness of another form, leaving Mists which delude the eye and conjure phantoms which may drive those on the Mountain over the edge to their deaths.
It is no accident that Hassan I Sabbah was called the Old Man of the Mountain. High above, even Aer thins, leaving us with a second form of blindness – that of the previously Unseen. Blinded by such crystal clarity those occupying Mountain-Space must either descend, or be rendered completely disconnected from the world below. Mountain is Much Erath and Aer with more Water than Dust Further, consulting with the legend of the Assassins we find that the Order held valleys and passes from which they drew their resources, secure places which were networked by the hidden trails and mine-workings which led them /down/ into Mountain-Space without actually leaving the space and returning to ground level. The tactics of the Assassins are well known, their combination of mysticism and expertise, taught to them by one whose very title speaks of his union with the space, are indicative that the fluidic-swarm nature of the War-Machines must essentially unify with the Space that they occupy, injecting themselves into a symbiotic relationship which allows the non-specific Hunt-Seek-Dwell-Kill to occur.