Fungal Warren

Fungal warrens are the joyful, lively "gut" of the rootbed. Here, Nature's detritus is gathered in great drifts and broken down for reuse. Out-of-flight dragons may picture a stinking trash heap, but Nature knows that death is only the precursor to life, and that nowhere are the two closer than the halls of a warren.
== Function ==
The chief role of the warrens is to cycle nutrients on a regional scale. Most soil in settled areas of the rootbeds is enhanced with warrens compost, which provides nutrients that can't be leached from rock by founder-lichens. By processing materials from the surface, as well as from over-fertilized regions of the rootbeds (ex: those that have spread to rock naturally rich in soluble compounds, such as phosphate rock), warrens maintain a balance that maximizes the spread of both surface and subterranean Nature.
A common misconception is that warrens smell like rot. While true in a strict sense, the smell of well-tended compost is minimal, typically sweet and slightly earthy, and most warrens compost is very well-tended. In fact, their management of decay provides nutrient turnover rates orders of magnitude higher than what the Behemoth could manage alone, and their knowledge of decay (passed along mostly as oral tradition) rivals that of any other great art. 
In addition to gathering materials, warrens dragons serve as an "immune system" for the region. If a local druid determines a species has overgrown and is threatening the balance, warrens are called in for a cull. Similarly, while the Behemoth's roots are the primary conduit for distributing reclaimed nutrients, warrens dragons can also create concentrated magical fertilizers for transport to struggling regions.
== Culture ==
Many warrens dragons have no permanent lair, instead sleeping where they tire, sharing from a communal food stash (often dried meat and fruit, mushrooms, and various fermented goods), and congregating in side chambers for chatter, music, and handicrafts. As one joke goes, warrens dragons can't resist the urge to bring anything to their warren, including visitors. Their hospitality is legendary, doubly so to those willing to join in their work. 
Fungal warrens are viewed as a more "plaguey" aspect of the rootbeds due to the abundance of decay, heavy use of leather and bone in crafts (natural rot-resistant byproducts of warrens processes), mycelial ground, free-flowing community groups somewhat reminiscent of mirror packs, and the simple fact that Plague dragons seem likely to feel at home. But the warrens are a lynchpin of Nature's accelerated cycle; only by their altruism can the Flight achieve the greatest growth. In fact, veneration of the Behemoth is more common in many warrens, which worship the Gladekeeper and Behemoth as dual aspect. The roots they tend and feed are often lovingly decorated, and their shrines (though made with skin and bone where others might use leaf and wood) are treated with as much honor and care as any other in the Flight.
== Construction and Layout ==
The heat and moisture of decomposition fuel a constant explosion of growth, which in turn provides the construction materials required for a warren's day-to-day function. Compost piles are buried deep in all manner of growing things, with fungi being the most common. They coat the walls and roofs of the warren in mushrooms of all shapes and sorts: shelf fungi strong enough to support dragons, cap fungi large enough to shelter under, "snows" of spores that can bury the ground an inch thick. These growths are shaped into mycelial pads and platforms to serve as everything from fencing to full-fledged homes, hung with storage nets and lights. Strong though they are, these structures are always broken down in time to give rise to new generations of fungi.
Warrens tend to be constructed around one or more vertical shafts, which are used to transport materials from the surface and/or deeper in the rootbed. Further tunnels, reinforced with timber, bone, and mycelia, serve as storage or community space. Most transport shafts are lined with fungal "micro-gardens". These are caused by rotten wood and other materials impacting the transport shaft, violently flinging decaying material into any pocks or crevices along the way.
While smell is rarely a concern, visitors should still be warned that the sensation of warrens can be unpleasant for the unprepared, as the ground tends to be squishy and/or rubbery due to mycelia. It's also important to be aware of your surroundings, as warrens are often fed from higher tunnels. A shower of leaves and twigs may warn of something larger on the way. While warrens dragons work in shifts to avoid taking a log to the head, wandering visitors are unlikely to know where in the shift they are.
While generally seen as joyful, chaotic, and a little feral, there's another side to warrens life. Insulated from the timber falls by earth and fungal bulk, side chambers become quiet and still. Mycelia are shaped into soft, pale forms and hollowed out to make houses. The streets are swathed in growths that swallow up the clacking of claw on floor. Fungal bulbs cast a glow that catches the spores as they drift from the ceiling. All together, these places resemble nothing so much as a village, slightly tumbledown, frozen in time on a winter's night.