Biome placement for fantasy worlds

[mbartelsm]

I did some quick montages were I included your colors scales with the data I used in my tutorial. It was made hastily but I think it could be interesting for comparison.
I rotate your tables by 180 degrees to go from high to low (left to right/ top to bottom)

The precipitation table was imported from Excel via a print screen (I know how awful it is ). The categories at the top and those of the left have only min/max with the max capped at 200 (because more rain over 200mm had little impact with Earthlike temperatures on the climates).
For the other categories, the bottom right is the minimum, the top right is the maximum and the other two are the average.

* I don't remember if the lowest category is supposed to 0-10 or 0-12,5, because I did this table a couple of weeks ago.

So normally, unless I'm missing something, the precipitation categories, once combine (summer and winter) should cover all the possible combinations of the Holdridge system. Except for the rainiest one, over 4000 were there would only be two categories instead of three. Meaning that the rain forest would be the same as wet forest. Like if there is a big difference.

Pretty much, there is something that's been troubling me though, and it's the fact that even though the combinations don't cover the whole system, the do extend beyond it, especially as you progress to colder climates. It bothers me because, with my limited climatic knowledge, I don't understand the implications of having such combinations nor the reason they are not included in the first place.

mbmartin copie 2.png Just to be sure, you used 5 different colors here or 6?

I messed up there, it's supposed to be 6 different colors.

This is the yearly average temperatures. I used this to determine the aridity index in another Excel sheet.

temp copie.png

temp 2.png

I'll update my notes with this, thanks for sharing. There is one problem though (in fact, the biggest problem about Holdridge's system), and it is that I didn't use average temperatures, but average biotemperatures. Biotemperatures being defined as the range of temperatures that fall within the 0° to 30°C range, and average temperature being the sum of the monthly averages that fall in that range, divided by 12. The problem with using biotemperatures is that we have only two temperature maps available, one for January and the other for July, not the whole year.

I tried to solve the problem by assuming a sine wave pattern for a year's temperature change, as can be seen of wikipedia's climate charts
Untitled-1 copy.png
With the help of the sine function I assigned each month a multiplier value with january and july at the peaks and did some simple math to find the average temperature for each month. After that I calculated the biotemperatures for each possible combination of temperatures, the result below.
Untitled-1.png
And the partly expanded table (the top values are the multipliers, the bottom ones are the month's guessed avg temperature).
Untitled-1.png
For obvious reasons, my temperatures differ slightly from yours, but that's something I'll fix for the next version.

There is a trend I noticed in climate charts that I want to try to reflect, and that is that the curve for winter seems to be steeper than that of summer, that is, the coldest period is shorter in duration than the warmest period. I don't quite understand why but it seems to be present in the great majority of charts I've seen.

Now about you results, aside form having some weird climates (having deserts near the polar circle), I see that there are many inaccuracies between the climate and biome maps. Some deserts disappear to become forests and vice-versa?

This is really a problem with the way I decided to simplify Holdridge's System. Because I merged many categories it looks as if some biome transitions are too sudden. The deserts near the polar circles are actually cold deserts, and the forest desert transition is actually a forest-woodland-shrubland-desert transition. That is something I'm planning on fixing by adding at the very least a woodland category.

Also, I think the coniferous forest is misleading. These foresst can also be found with milder climates like in California and British-Colombia, not just in cold places. Personally, I would rather use boreal or taiga to define that specific biome.

You are absolutely right, I think boreal forest describes the biome much better. Do you suggest something for mixed forests as well? it's the category I'm most uncomfortable with.

Btw, as a graphic designer, do you sometimes have to design things that are made to be used by color-blind people? I was just thinking that these people would find our tutorials pretty annoying since they are highly dependent on using the right colors.

I apologize for that, this was made kind of in a hurry as I only really have free time during the weekend and wanted to finish the first version before monday. It goes without saying that it still needs a lot of improving.

EDIT: I think I can upload a new version today, with some of the more immediate problems fixed. A more complete update will have to wait probably until saturday because of my work.