Mycorrhizal Catacombs

The Mycorrhizal Catacombs of Caudal D are subterranean geological features created by a combination of biological processes found only in this region.

Geography

Most of the street-level terrain of Petalcap Vale is a massive, living carpet of fungal, lichen, and arboreal growth built up over thousands of years. This network of biomass is so deep and complex that it has its own hollows and caverns large enough for verdials to treat as homes, private work areas, or even sites for agri-mines.

Ecosystem

The 'Mycorrhizal' part of the geography's name derives from the fact that, in many of these hidden voids, the symbiotic interconnections between the fungi and regular plant life of the cube are in clear view for explorers. Shallow voids are sometimes employed as root cellars for this reason, as verdial botanists can use this access to perform biological experiments, take samples, or treat diseases in the plants growing above.
Of course, expeditions into the Catacombs are dangerous for reasons beyond the usual subterranean dangers of entrapment, bad air, or falls in the dark. There once were - and may still be - pockets of assorted Distal life hidden in the deeper recesses. Distal urticator and Distal polyp colonies in the Mycorrhizal Catacombs are extirpated whenever they are found. The Petalcap Vale Customs Authority works dilligently to prevent and contain the spread of Distal life forms, but there are times when newly discovered infestation sites or events like a black sun will cause invasive species to spread despite their best efforts. Thankfully, though some of the Catacombs reach all the way into the commissures leading to the other cubes of the Caudal Tesseract, a combination of chilly conditions and non-Distal sunlight found there helps check any encroachment of Distal life into the rest of The Verdial Arc.

Ecosystem Cycles

In the Catacombs, the mats of different vegetative material live in a mutualistic arrangement. The fungi help to fertilize the plants by, among other things, fixing nitrogen and decomposing organic waste. In exchange, the plants provide the products of photosynthesis to the fungi. Mosses and lichens take up residence in the moist, protected spaces created by the other species.
Over time, fallen macrofungi and timber provide the structurual framework and food upon which all of this mutual growth takes place; because some parts of this living terrain decay faster than others, hollows are created - the Catacombs themselves. In these underground spaces, phosphorescent fungi and molds provide a meagre source of light for the few simple, alien species of plants and lichens which grow there instead of on the surface. It is currently believed that this might have been where the first reservoirs of the Caudal lichens might have developed, entering into symbiosis with burrowing mammals before making the jump to large hosts - including early humans deposited in Caudal D at the end of The Curved Time.

Tourism

Darkfrost celebrations are occasionally held in the uppermost portions of the Catacombs, typically those employed as root cellars. The insulating mass and ongoing metabolism of the surrounding plant matter provides a degree of warmth during the cold winter months.
While verdials who were born in the vale and lived there for a long time often find the Catacombs passe at best and part of their daily work at worst, visitors from other regions of the Manifold often find the place fascinating. Visitors from the Coalition states, being from the desert cube of Medial C, are particularly enrapt by the sheer volume of greenery to be found in and around the Catacombs, as are Rostran visitors from the Red Velvet Association holdings.
More than one Biocosmist coven, regarding the Catacombs as a sign of the Biocosm's reality, has attempted to set up private hermitages in the depths. More than once, these same covens have had to be rescued from the patches of Distal polyps they uncover there. While it is accepted by the PVCA that these incidents are simply cases of accidental discovery, the fact that the story has played out more than a few times has led some to wonder if the Biocosmists might actually be intentionally spreading the invasive species - perhaps in a misguided attempt to 'restore the natural order' through the reintroduction of Distal species to their native ranges. Regardless of intentions, most Vale Verdials are suspicious of Biocosmists anyways and take a dim view of the religion appropriating the Catacombs for 'un-verdial' purposes.

Type

Cave System

Location under

Petalcap Vale (municipality)

Owning Organization

Petalcap Vale

Contested By

• Verdant Order
• Way of the Biocosm