Document ETH-238: Calcium in the Ecosystem

One of the most unusual aspects of Eth, compared to Old Earth’s, is the unusually low carbon to calcium Ratio. Carbon is almost completely absent from the rock itself, as soil is practically nonexistent. Meanwhile calcium makes up a high percentage of the ground, and the atmosphere is rich in calcium particles, although this is not a result of natural processes (see below). Therefore, the organisms of Eth have evolved to use calcium in building many structural aspects where carbon would be used on Earth.

Calcium Cycle
Calcium therefore is a vital part of the ecosystem, forming a network between the organisms and plant. The substance acts much like carbon with autotrophs “fixing” simple calcium particles in the air into complex ionic structures, and heterotrophs consuming these and breaking them down for energy (although the carbon-oxygen cycle on Eth is functionally identical to that of Old Earth’s).

“Treeths ”, “Straths ”, and “Mooths ” all perform the task of extracting it from the atmosphere, however “Laths ” obtain calcium from groundwater. The consumers of Eth rely on these producers (though laths, for the most part, lack predators) to from different types of structures, which specialized organs and organelles can break down to release energy. All consumers release calcium particles into the atmosphere, used by producers again. This explains the abnormal amount of the element in the atmosphere, which would normally settle in a few years without life.

Calcium-Water Interaction
A common event, the flash floods of Eth also play an important role in the ecosystem. After Treeth booms and busts, most of the ground is covered in indigestible calcium waste products. The flash floods are able to dissolve this calcium en masse, returning it to the ground. The material is eventually returned to the atmosphere, as laths take in the calcium-rich water.