Terraformed Ecosystem Peculiarities

[Sindri]

What are some ways that an ecoystem designed for a terraforming project might be somewhat unusual compared to natural ecosystems?

[Anthony]

Assuming it was done recently, biodiversity will be low, you won't have much in the way of buried hydrocarbons, and depending on where you are in the process, you may not have any animal life at all except for those required for assisting in plant spread and reproduction -- only the autotrophs are actually directly useful for creating a breathable atmosphere and the like.

Basically, expect it to be about as natural as your average high tech farm.

[Zeta Blaze]

Other angles of concern are whether you are converting a nearly correct native biosphere or building one from scratch.

also one proposal I have read is that on an atmospherically stable world where introducing bio diversity is ready you will land a bunch of pocket ecosystems (think large biologically accurate modern zoo exhibits) complete with parasites and diseases about a days travel by foot apart and then let nature more or less take its coarse building hodgepodge new ecosystems.

[Agemegos]

Originally Posted by Sindri

What are some ways that an ecoystem designed for a terraforming project might be somewhat unusual compared to natural ecosystems?

Well, it might have limited diversity, in particular lacking "living fossils". There probably won't be a pattern of regional arrays of unrelated organisms in similar niches such as we have on Earth: nothing like Wallace's Line or the parallel arrays of New World and Old World monkeys, or of marsupial and placental biosystems. Ecosystem engineers aiming for rapid cheap terraformation probably won't bother to produce one ecosystem of related herbivores, carnivores, and insectivores ranging up to megafauna in ~Australia and another, all related to each other, in Afroeurasia and and another in ~North America and another in ~South America.

There might be a preponderance of organisms that spread widely, as with wind-borne and current-borne spores, light seeds, larvae etc. There might be a preponderance of plants that are capable of pioneering sand, shingle, and rock flour, there to form soil. In my setting I have used vast forests of Casuarina trees as an indicator of recent terraformation: their seeds are light and easily spread; they colonise sand and shingle; they fix nitrogen and drop copious drifts of nitrate-rich "needles" to form soil; their root-mats resist washing away in floods: that makes them an ideal terraforming species for terrains that lack soil.

Other angles of concern are whether you are converting a nearly correct native biosphere or building one from scratch.

The former may be considered an environmental atrocity. In my setting there is an interstellar NGO called "Greenwar" that campaigns tirelessly against the serial mass-multiple genocides the the Eichberger Realty Corporation and the Imperial Terraformation Advisory Service commit in making habitable planets for Man.

Originally Posted by Zeta Blaze

one proposal I have read is that on an atmospherically stable world where introducing bio diversity is ready you will land a bunch of pocket ecosystems (think large biologically accurate modern zoo exhibits) complete with parasites and diseases about a days travel by foot apart

One per thousand square kilometres or so? 150,000 such zoos for Earth's land surface?

I think you might do better to release spores, fine seeds, larvae etc. into ocean currents, high-altitude winds, rivers etc. and introduce dispersal vectors.

Remember that unless you're planning to exterminate an existing biosphere you not only have to oxidise the atmosphere but create the soil. There are millennia of work to do before you introduce large land animals. To short-cut the evolution of organisms adapted to the changing environment, you will seed the planet several times, each time introducing forms of life that are suitable to survive in the aftermath of the last lot poisoning itself. So the work will have to be done over and over at intervals of millennia or perhaps centuries. Better make each episode (until, perhaps, final landscaping) cheap.

[Flyndaran]

No parasites unless absolutely necessary for some odd reason.

[Agemegos]

Originally Posted by Flyndaran

No parasites unless absolutely necessary for some odd reason.

Maybe, but Freefall makes the opposite argument in this and the two following strips. Parasites might well be vital to damp oscillations in predator-prey cycles.

[Flyndaran]

Originally Posted by Agemegos

Maybe, but Freefall makes the opposite argument in this and the two following strips. Parasites might well be vital to damp oscillations in predator-prey cycles.

I don't buy it as necessary. As much as the even slightly limping gazelle sign is very "loud", it's not like predators prefer diseased animals. Not to mention that many parasites jump to the predators causing major trouble.

It's not like TL 8 people would terraform. By the time science advances to that level, they would have to be able to fix any hypothetical minor dependencies of species on pervasive parasites.
Look at few, but admittedly real, problems humans in modern parasite free environments have. A slightly increased rate of autoimmune disorders isn't that huge all things considered.

[acrosome]

Unless a native biosphere was being displaced in addition to no petroleum there'd also be no limestone (and thus very little flint or chert), no marble, etc. And thus lime is hard to come by, you need to find alternatives for cement. If you terraformed a world that historically lacked a hydrosphere, like say Venus, there'd also be no sedimentary rock beyond volcanic aggregates. So no sandstone, mudstone, slate, etc.

Personally, if I were a ecological engineer I definitely would include parasites. No human ones, but for the rest of the biosphere, yes, especially if the goal is to have one that doesn't need constant maintenance. I think you're much more likely to lose the really annoying and pointless things like mosquitos, though. Probably the more annoying zoonoses, too.

[Anthony]

Originally Posted by Agemegos

Maybe, but Freefall makes the opposite argument in this and the two following strips. Parasites might well be vital to damp oscillations in predator-prey cycles.

You pretty much want wild uncontrolled excess in the prey. Actually, for a long time you probably only want plants, feeders are what you introduce when you want to stop the process.

[Johnny1A.2]

Originally Posted by acrosome

Unless a native biosphere was being displaced in addition to no petroleum there'd also be no limestone (and thus very little flint or chert), no marble, etc.

But does that necessarily mean that there would be no calcium carbonate type minerals at all?

Personally, if I were a ecological engineer I definitely would include parasites. No human ones, but for the rest of the biosphere, yes, especially if the goal is to have one that doesn't need constant maintenance. I think you're much more likely to lose the really annoying and pointless things like mosquitos, though. Probably the more annoying zoonoses, too.

If you're taking the long evolutionary view, mother nature will provide the parasites for you over time. It's too effective a niche to go empty for long.