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View Full Version : For ecologists: story sense for a constructed ecosystem



SPMiller
04-27-2008, 07:31 PM
All right. Apologies for long post + lots of info. I've finished my first fantasy novel and I'm striving for verisimilitude in setting. Here's some general information about the region:

Soil: deep, mildly alkaline
Bedrock: limestone, slight dip
Topography: hilly/rolling (but not Karst... there's surface water)
Drainage: dendritic
Climate: cold winter, long/mild summer, brief transitional seasons
Precipitation: 25-35 inches annually (depending on location)

The kickers:
1) solar energy input is restricted to what can pass through the equivalent of light cloud cover... possibly leading to mixed boreal style forest + grassland mosaic
2) the region is divided into microhabitats with varying dimensions, often on the order of several thousand square miles
3) any mammalian creature (due to certain neocortex mutations) is killed when trying to pass the boundary between microhabitats

I figure most of the land would be covered by grasses and shrub forms of trees. At higher elevations the shrub forms would vanish, and at lower elevations closer to water sources there would be more tree forms. Most trees would probably be coniferous (possibly of order Pinales) with deciduous trees (possibly of order Fagales) in Riparian zones.

Fauna would include a pretty decent range of non-migratory herbivores both large and small. Carnivores, not so much--there might be a few instances of small-to-medium sized carnivores such as wolves and cats. And, of course, some good old omnivores (such as bears).

Now from here I began speculating and inventing new life forms. The event which led to this poor-solar-energetic environment also triggered widespread mutations in native species, leading to the creation and dominance of herbivorous Ice-Age-style megafauna in the absence of significant predatory populations. In theory, the large size of these herbivores would allow them to survive brief, harsh winters without needing to migrate to warmer climes. In some microhabitats, there are also populations of large predatorial species.

Food supply is still a bit of a problem. The conditions don't seem favorable for agriculture, so the human diet would probably consist primarily of protein (nuts, animals, fish) and possibly berries. I'm working with a population of just over 200 humans, so low nutrient density (per land area) shouldn't be much of an issue.

Is all of this reasonable and consistent? Does anything leap out at you as impossible or impractical? Any further input or cool ideas I could use?

Kathie Freeman
04-27-2008, 08:14 PM
I'm thinking your mega-herbivores would very quickly consume all the vegetation in a given area if they couldn't migrate, although a thousand square miles isn't what I would call a micro-habitat. A micro-habitat is more like a few square yards next to a cliff or waterfall, something that blocks or alters normal air circulation.

SPMiller
04-28-2008, 07:21 AM
Ah, it doesn't surprise me that I've flubbed some of the terminology, because I'm very far away from my own area of expertise here.

I can move the neocortex mutation much closer to humans in the history of this fictional world's evolution. That would enable megafauna to migrate to a large degree while still keeping humans "trapped". It'll require some small modifications to the text, but that's fine with me. Thanks!

jennontheisland
04-28-2008, 05:50 PM
The size of your micro-habitats jumped out at me too.

Non-migratory animals, in particular carnivores, would have to be small and slow to reproduce (1-2 offspring per litter) in order to be sustained by small non-migratory herbivores, and there would be distict episodes of boom and bust in population sizes. This could affect the humans in terms of food supply; some years there'd be lots of yummy herbivores and little competition from carivores; other years, they'd have to resort to eating carnivores, a dangerous and less tasty option.

The humans may be able to cultivate fruit trees.

LIVIN
04-29-2008, 03:09 AM
3) any mammalian creature (due to certain neocortex mutations) is killed when trying to pass the boundary between microhabitats

I figure most of the land would be covered by grasses and shrub forms of trees. At higher elevations the shrub forms would vanish, and at lower elevations closer to water sources there would be more tree forms. Most trees would probably be coniferous (possibly of order Pinales) with deciduous trees (possibly of order Fagales) in Riparian zones.


I would think that if the animals would be killed when passing from one zone to the other (point 3) then... the following paragraph would not be applicable, in that I would expect a lot of deviation as opposed to things being so consistent.

SPMiller
04-30-2008, 03:42 AM
Non-migratory animals, in particular carnivores, would have to be small and slow to reproduce (1-2 offspring per litter) in order to be sustained by small non-migratory herbivores, and there would be distict episodes of boom and bust in population sizes. This could affect the humans in terms of food supply; some years there'd be lots of yummy herbivores and little competition from carivores; other years, they'd have to resort to eating carnivores, a dangerous and less tasty option.

The humans may be able to cultivate fruit trees.Ah, yeah, I was going for emphasis on K-selection. I don't know how to force gigantism, though. By allowing most mammals to pass through the boundaries, the non-migratory problem is solved.

I can make the habitats larger, but there's a limit to how far I'm willing to go with that, so allowing migration will help.
I would think that if the animals would be killed when passing from one zone to the other (point 3) then... the following paragraph would not be applicable, in that I would expect a lot of deviation as opposed to things being so consistent.Even in my original conception, many living things (birds, insects) could move between zones and encourage flora consistency. The wind could also carry seeds, spores, and so forth. But even that's out the window now with everything but humans allowed to move around!

Thanks all.