This was a fairly recent note. Not everything in my notebook dates back to the twentieth century🤣. This was actually posted on December 27th of 2017, in fact.
— The Crystalglass Forest —
On a planet who’s interior has cooled somewhat beyond maintaining plate tectonics, the lifeforms have evolved a number of adaptations to the increasing scarcity of atmospheric carbon.
One adaptation found particularly among primary producers in high-latitude habitats is the crystalglass forest.
To survive the long, cold winters, the biological expense of maintaining living foliage in the absence of light is untenable. It is also unreasonable to expend resources during the intense, but short growing season creating entirely new foliage. Added to that, the fact that, even in the extremest environments decomposition microbes will feast on any source of carbon that isn’t strongly protected and you have problems.
The crystalglass “trees” have dealt with all of these problems by forming a thick “bark” and a foliage consisting of multitudes of thin, sharp “needles” composed of tough, transparent, crystalline borosilicate fibers.
During the growing season, pores within these structures circulate an aqueous solution of chlorophyll-analogue bearing cells and other cells intended to break down and rebuild the borosilicate structure. Where there are breaks in the integument, those construction cells will leak out and begin to build new foliage. Gradually, as new needles are built, the structure of old needles is melded together into new bark protecting the living woody inner tissues of the plant. As the living inner parts of the plant grows, the innermost layers of the borosilicate integument are broken down to make space for growth, as well as to free up boron to build more foliage.
As the long, cold darkness of winter settles in, the trees hunker down, withdrawing water and carbon-rich cells into the protected inner parts. The largely opaque to translucent green foliage and skin of the plant begin to bleach into transparent crystals.
Younger and smaller plants will withdraw their living tissues entirely beneath the warming embrace of the ground. Living tissues can be seen as dark masses of greenish- to reddish brown opacity deep in the trunk and heaviest branches of older larger trees.
The appearance of crystalglass plants generally follows a fairly standard form. The smallest plants, regardless of their longer-term fate, will consist of a living taproot with a spray of crystalline needles right at ground level. Larger plants will form a trunk and perhaps branches shooting skyward. Cracks in the crystal bark will usually spray forth needles of foliage, but some of the larger species will avoid foliating the shaded lower parts of the plant in favor of developing thicker, more resistant bark as living tissues emerge from the ground.
Although originating in the higher latitudes, the relative lack of sensitivity to most predation and fire has lead the plants to adaptive radiation into warmer biomes. Some of these plants have abandoned borosilicate foliage in favor of faster-growing living foliage, but retain the thick armored bark.
This was, to some degree, inspired by reading about Epona quite some time ago. Even on first reading(okay, probably second or third reading, but whatever…), it struck me that there would probably be some organisms that found a use for, never particularly scarce silicon. Probably not in any sort of energy-producing metabolic process, but perhaps as a structural materials. An early development of that was a sort of silicate coral in submarine environments. I could see my imaginary planet having such things as an independent evolutionary line from the crystalglass forest organisms. It wouldn’t be a total no-brainer, the use of silicates would probably be a compromise between the benefits of a large strong structure using less scarce materials and the energy cost to produce such things. If the energy costs were two unfavorable, it would still be conceivable that plants and perhaps even some animals might evolve to use physically pulverized rock crystals glued together with an organic cement as a skeleton or shell. The idea seems both plausible enough and interestingly alien enough to be worth examining in greater depth.
What are your thoughts? Please feel free to share your thoughts and questions by commenting.