The Ups and Downs of the Ant Forest
The Ultimocene sees the highest diversity so far of myrmecophyte trees. The distant descendants of sunflowers, these plants sport woody trunks, broad leaves and inconspicuous blossoms. They survive in close association with ant colonies which find lodging in specialized hollow channels within their trunks and branches. The insects, in return for their home, help keep the host tree free of plant-eating pests and discourage competing plants from encroaching upon its space by trimming back the branches of neighboring trees which come too close and destroying seedlings that take root too near to their host's trunk. They also pollinate their flowers, removing the need for the tree to grow colorful petals to advertise to passing insects, and in the most specialized forms they also distribute the plant's offspring and in doing so each new generation cultivates its own host tree in the most ideal location. The ants find sustenance from the insects and plants they kill from on and around their host and in return their waste products deposited inside the nest fertilize the host tree, improving its health and vigor.
Advanced ant trees and their symbiotic colonies reach sexual maturity simultaneously and from there are synchronized in their breeding efforts. Sterile workers pollinate the tree's small, hidden flowers and later sexually mature flying males distribute the tree's seedlings on their way to start new colonies and attract a mate. The seedlings of the tree, already germinated and deposited in an ideal location to grow, with bright light and no nearby competitors, grow quickly. The fertile king ants dig a burrow underneath the seedling to which they lure a young flying queen, and the two then begin to build their own colony there. The queen lays eggs, and the pair then feed the larvae with small insect prey, all of which eventually is returned to the soil underneath the young tree's roots as nourishment that helps it to easily reach heights of six to eight feet within its first four to five months. As temperatures cool in the autumn in temperate climates, their stems are large enough for the ant colony to move into. Leaving the original underground nest behind, they climb up through specialized channels in the trunk and hibernate through the cold. In the spring, they begin expanding the channels and building the beginnings of their mature nest, which will be the sole home of the colony for decades to come.
The queen ants of these trees are extraordinarily long-lived, able to live decades. The trees, conversely, are relatively short-lived - through they grow extremely quickly in youth, they die at a relatively young age versus related trees that do not support ant colonies. Once their colonies lose their queens they collapse - and so too goes the ability for the tree to reproduce. Additionally, without its colony to provide it nutrients, its growth slows, and quickly neighboring trees crowd it out and overtake it - a process made all the more rapid if those other trees, too, are ant-symbiotic, as their own colonies will begin to trim away all the leaves of the aged specimen, eventually causing its death.
Ant trees, armed with aggressive soldiers ready to attack any threat, are difficult for herbivores to browse on and so the main constraints to their growth are one another - where the tips of individual trees brush together ants living in each canopy fight and attack the invading branches so that the crowns of individual ant trees are always visibly separated by gaps that shine light down to the forest floor. While these forests are relatively free of large herbivores, they support large numbers of specialized ant-eating birds and animals and many herbivorous insects which have adapted to flutter about, taking nibbles of branches and avoiding the patrols of the ant guards. Even so, the total damage sustained by these small pests is minimal versus the damage which would come from herds of large animals, and so it would seem that for the most part, the ant forest is immune to most threats that can damage other woodland communities. But this is not the case.
While ant trees occur at low population densities in all forests, true ant forests composed almost entirely of them are unstable and short-lived ecosystems. Chimera trees and most other ant-symbiotic plants are pioneer species that are the first to colonize new territory after other trees have fallen or fire has ravaged the land. Only able to thrive in full sun and fertile soil, their ant distributors plant their seedlings in brightly lit, fertile areas with few competing trees for it is only here they can reach the maximum rate of growth which is required for them to be able to support the ant colony within their first growing season. Where severe weather, flood or fire has felled whole swaths of forest, ant trees appear to take advantage of the space. They grow in swaths, the only limiting factor in their growth being one another, and during the span of their lives little else can harm them. Once an ant tree has established, it functions as a combination of animal and plant. By utilizing its ant colony as an extension of itself, it can hunt and bring back nourishment for itself in the form of small animals and other vegetation that are taken through the digestive systems of the ants and deposited nearly inside its trunk where it can be absorbed. The system, when resources are abundant, allows the tree to grow at an extreme rate of speed that no other tree can match. But wherever so many ant trees grow together, the ants which live within each of them will inevitably outgrow the means of the forest around them to support them. Having stripped the land bare of all food, either plant or animal, the forest becomes a largely sterile place, and the ant colonies begin to collapse. Indeed, most ant forests begin to falter in this way within twenty years. As colonies die, the trees are left vulnerable and gradually large herbivores move into these tracts to feed upon them. With no defenses of their own, they are highly edible and struggle to survive even mild damage which other trees would easily endure.
Another threat is also emerging by this time. Though the ants stripped most of the forest floor clean of other life, one group of plants in particular was largely ignored. Gluesap trees (also known as glue trap trees), their own seeds typically distributed to the same initial clearings that the ant trees took root in years ago, have been biding their time. Slower-growing, and more tolerant of the shade, they grew slowly but steadily underneath the canopies of the pioneers, left alone by the insects due to their tacky latex-filled sap, easily strong enough to adhere the jaws of insects together. Now, as the ant trees begin to die, the sunlight reaching the forest floor increases and speeds their growth. The young gluesaps rise to take their place in the sunlight, leaving the last struggling ant trees to die in their shadow. Slow-growing but very long-lived, the gluesap trees inevitably form the climax forest all across Serina, and their return to the woods is followed by countless other plants and animals that were previously inhibited by the presence of the ant trees. Once mature and past the height of the canopy the trees produce far less of the irritating resin that gives them their name, for at this stage in their life they are much less at risk of substantial damage from ant attacks, and so the leaves and seeds of mature trees are edible for a wide variety of animals, particularly tribbets and softbill birds. Furthermore a wide variety of other plants and smaller shrubs are then able to grow beneath the gluesap canopy, many of which are very edible and lack any spectacular defenses of any sort, for without direct competition with ant trees they needn't be so overtly offensive. The climax forest is therefore the most viable and long-lasting forest community, supporting large and small herbivores, predators, and many more invertebrates such as snails and worms which are among the first to be locally extirpated when ant populations rise to plague-like levels in the later years of the ant forest community's lifespan before they starve and die out.
Whenever a climax forest is damaged or otherwise new land opens up to support an ant forest, specialized ant-eating animals converge and experience a brief period of extreme abundance. As food resources dwindle and the colonies die off, these ant predators must quickly disperse or else they, too, will die out. Ant-eating birds make a healthy living merely by living a nomadic life, searching for ant forests, breeding until the food runs out and then finding another elsewhere. The lethargic anteater muck, however, is much less mobile and cannot easily relocate when their own forests begin to die. Able to survive only at low population densities in the climax forest, where non-symbiotic ants are present but at much lower levels, many of them die along with the trees as the pioneer forest grows into its mature state. Those which can find new territory will congregate along the many isolated ant trees that still pop up sporadically in the forest, often wherever a mature gluesap tree has fallen and sun once again reaches the forest floor. Such a spot is again ideal for their growth and ants having traveled from other isolated trees in the wood quickly locate these sites and deposit their seedlings, which rapidly grow to fill the space. These isolated specimens growing here and there among the gluesaps live longer and are more healthy than those growing in dense monocultured stands, for they do not have to compete with others of their own kind and furthermore are better supplied with food from the more varied forest around them. While stands of ant trees growing together last just around twenty years, such loners can last half a century or more. But eventually, they too die, and a new young gluesap takes theirs place in the natural process of succession. Ant trees have experienced some of the greatest innovations in the plant kingdom on Serina, but since the evolution of the gluesap lineage, they no longer rule the woods. They grow quicker than anything else and take over spectacularly, but they burn out as swiftly as they appear. The ant tree is a sprinter, but gluesap has the endurance. When it comes to trees, slow and steady always wins the race.
The ant tree, just as it is not as invincible as its adaptations at first make it seem, is also not inherently damaging to the environment. Isolated specimens living within the limiting confines of the old-growth forest provide important nest sites for birds and molodonts, for the ants protect their nests from pests, providing the animals find their food elsewhere and do not harm the tree. The ants, in moderation, feed a number of intriguing specialist animals. It is only when the ant trees overtake great swaths of land, to the exclusion of all else, as occurs when the climax forest has been destroyed by natural forces, that they decimate the forest ecosystem. Even then, however, the condition is never permanent. Inevitably the trees use up all their resources, lose their symbiotes and die out, to be replaced by the rightful and benevolent rulers of the forest, the gluesaps.