It says Forest Preserve increases the Chance that Forest grows. Sounds great. Indeed i looked up in the XML and found out, that the normally <iGrowth> for forest is 8, while with preserve it's 64.

":goodjob:" i thought. 8 times the chance!!! Sounds great. Then i built a couple of those preserves. And waited. And waited, and waited, and waited......

There were no roads, no improvemnts - i actually tried to preserve this spot from the beginning of the game for the national park. There were 11 forests and 5 Jungles, and i hoped for 4 more to grow. It would be a "perfect 20" National Park city. Not a single one grew until the end of the game.

"[pissed]" i thought, and went to look up in the SDK what those numbers actually mean. Turns out, its a

[iGrowth * 1.25] * (# Adjacent Forests) out of 10000 Chance.

0.001 or 0.1% chance a forest will grow, if one forest is nearbye, 0.2% for two adjacent forests, 0.3% ....

[Edit] Only the 4 Plots to N,S,E,W are concidered adjacent here, not diagonal plots. So at best 4x the chance.


Well, i understand with all those Choping hammers, you cant make forests grow too fast. I.e. Early in the game. But let us take a look at the Forest Preserves now. It has 8 times the chance after all. So what ...

A whooping 0.8% Chance a Forest will grow on a tile adjacent to a Forest Preserve. So after making a Forest Preserve - which is by the way awaiable rather late in the game - you will have to wait on average 125 turns for a forest to grow on a given adjacent plot.

Sure, it becomes a bit better with more preserves. A tile completely surrounded by 4 Forest Preserves has a 3.2% chance to get a forest. It's - again on average - 31.2 turns we have to wait for a forest to grow there.

[Edit] 4 is best we can have here, as diagonal tiles do not count as adjacent for this matter.

Wow! Just Wow!

I think it cries to be fixed/moded. I see how normal forest spread has to be limited - as said before: chopping - but for the Preserve i feel those chances are too low.

.....Wow! Just Wow!

:goodjob: That seems way out of whack!

Imho, the "help forest growth" of the forest preserve has to be seen like a bonus. The main impact is the happy faces and the interaction with evironmentalism/national park.

They should fix it so that workers can plant forest like in civ 3. It's just that they cant be chop for hammers anymore.

Imho, the "help forest growth" of the forest preserve has to be seen like a bonus. The main impact is the happy faces and the interaction with evironmentalism/national park.

I see it too. Why do you think did i wanted MORE forest to grow :D

I think its to stop people from both chopping AND getting a great NP city.

I like the system as is. It forces you to choose a path for any given city (early chopping hammers vs long-term bonus from the forest).

Now that you mention it, my most recent game was a forest rich capital. I chopped exactly three forest tiles clear at the start of the game (and one of them grew back!) Granted, it had gems, cows, stone, and a few fish, so I was able to live with every other tile forested. That was a fun game.

I built the national park and after that 12 forest preserves in the city tiles and soon more forest grew and soon I had 17 tiles of land with forest preserve...I think 20 is the max you can have. 17 specialists from park, +2 from mercantilism and statue of liberty...Representation FTW!

Good info, thanks.

At least in Noble, by late 1700, early 1800 you may have a chance to still find a relatively untouched pure jungle/pure forest spot, settle it then and wait for Biology. Save a GE for the National Park. I can do this in most of my games.

But in a recent game, one very awkward thing happened: I had my "build trade network" automated workers parked at my capital. By about 1815, I conquered my neighbor and found that he left a huge jungle area between two of his cities unsettled, yet culturally dominated. So I made a settler ASAP and found my pretty planned Eldorado city in the Amazon. Guess what? All of sudden my 12 workers turned into chainsaw-happy Brazilian cattle ranchers and proceeded to a jungle-destroying rampage to "clear" all of my precious jungle in 3 turns, before I could stop all of them (when I ordered one to build a reserve, the other was already tearing down the trees). If at least I had Greenpeace activists to tie themselves to the trees...

^^Automated workers are pretty evil when you don't have the "let the forests alone" and the "leave old improvements alone" ticked.... :lol:

On topic: forets in Civ IV are really badly handled.... I sometimes wonder why they didn't let to plant forests and apply a mechanism similar to the cottages ones, but reversed: a long time unworked forest would give a lot more hammers than a freshly planted one.

My automated workers won't leave forests alone even with the option ticked. I thought this was a bug? Because I'm quite sure this is how it works (for me).

^^Automated workers are pretty evil when you don't have the "let the forests alone" and the "leave old improvements alone" ticked.... :lol:

The case is I HAD this option checked, but it means leave forests alone, not jungles. I already said on another subject that our pretty liberal Sid Meyer is a bit self-contradicting: he values so much environmentalism as to make it a state policy that works wonderfully (as never seen in any civilization in History - try to implement an organics-only, pre-green revolution agriculture and see the famine roar even worse than in the collectivization process of China and Soviet Union).

Yet, at the same time, jungles are just low-producing, mosquito-infected, miasma-emanating unhealthiness sources, nothing more. What the World opinion would be if the Brazilian president had played too much Civilization and took this Sid approach regarding the Amazon Rainforest? Rainforest, that is, jungle...

Yet, at the same time, jungles are just low-producing, mosquito-infected, miasma-emanating unhealthiness sources, nothing more. What the World opinion would be if the Brazilian president had played too much Civilization and took this Sid approach regarding the Amazon Rainforest? Rainforest, that is, jungle...

They didn't done that already? :rolleyes:

Seriously, I bet that the jungle chopping in Civ would look a lot less atractive if the underneat grassland decayed to 0 F after some turns, like it happens in RL ( besides the Terra Preta phenomenon ( that nobody knows how to explain properly ) ). And of course, enviromentalism in RL would be:
- Far less productive per km2 ( or square mile ,it it pleases you)
- Far more human-intensive
Of course that current "industrial" ( like if the green thing wasn't industrialized as well ) agriculture is clearly energy deficient: for a example , to produce a kcal of apple you need to spend roughly 22 kcal of energy between fuel for the machines and the energy spent in the fertilizer making ( and I'm not counting woth transportation ), but I strongly suspect that the town people that praises the "bio" and "green" agriculture would maintain that opinion and be happy if they were forced to plow with animal and human propeled veicules and fertilizers with their own hands to have something to eat ( another effect of the Civ IV enviromentalist is the increase of :) .... )

jungles are just low-producing, mosquito-infected, miasma-emanating unhealthiness sources, nothing more. What the World opinion would be if the Brazilian president had played too much Civilization and took this Sid approach regarding the Amazon Rainforest? Rainforest, that is, jungle...

:rotfl:
I think we will never see a National Park with jungles in BTS, either by human or AI, which is a shame.

They didn't done that already? :rolleyes:

Seriously, I bet that the jungle chopping in Civ would look a lot less atractive if the underneat grassland decayed to 0 F after some turns, like it happens in RL ( besides the Terra Preta phenomenon ( that nobody knows how to explain properly ) ). And of course, enviromentalism in RL would be:
- Far less productive per km2 ( or square mile ,it it pleases you)
- Far more human-intensive
Of course that current "industrial" ( like if the green thing wasn't industrialized as well ) agriculture is clearly energy deficient: for a example , to produce a kcal of apple you need to spend roughly 22 kcal of energy between fuel for the machines and the energy spent in the fertilizer making ( and I'm not counting woth transportation ), but I strongly suspect that the town people that praises the "bio" and "green" agriculture would maintain that opinion and be happy if they were forced to plow with animal and human propeled veicules and fertilizers with their own hands to have something to eat ( another effect of the Civ IV enviromentalist is the increase of :) .... )

Hehehe, as for Brazilian government, we found the perfect, typical, folkloric anti-American rant answer: BLAME SID MEYER!

But as for agriculture, you're not talking about an energy resource, you're talking about super-diet apples! If the same mathematics would apply to calorie-rich resources as beets, corn or sugarcane, no one in his sane mind would be considering this as an eco-friendly option.

Though yeah, for the eco-Torquemadas, they'd be very happy living in a 100% "clean", non-industrial world where 7 out of each 10 children die before reaching 5 years.

Even if you have a forest-based national park with leave forests alone selected, your workers will still screw you as they will build roads/railroads next to your reserves, halving the chances for them to spread.
Moral: Don't automate workers that are on the same continent as the National Park unless the park is maxed out.

Create a new terrain that's a clone of the forest, call it "Man-made Forest". Allow it to be planted and interact with said wonders/etc.

was I dreaming or did environmentalism increased chances of forest growth ?

No you were dreaming

When I first heard of Forest Preserves, I thought they would be far better... my ideal would be

1. Build a Preserve on ANY plains or grassland (or tundra?) tile
2. IF it has no Forest/Jungle but is adjacent to a Forest, you can work it for 30-50 turns (like a cottage) and at that point it will automatically acquire the Forest
3. IF it has no Forest/Jungle but is grassland and adjacent to a Jungle, you can work it for 10-20 turns (like a cottage) and at that point it will automatically acquire the Jungle
4. It would give bonuses (happy/national park specialist) only if it was a Jungle/Forest Preserve (with some extra bonuses for a Jungle Preserve like +food and commerce.. once you had ecology... maybe even more if it was on a resource that goes obsolete like Ivory or Fur.. the only ones it could get AI put on)

But they really limited it

Now, with then new global warming model allow forest/Jungles as Global Warming Defense (both slowing the worlds global warming and acting as a defense against global warming that hits you), I'd really hope they would put it in

A whooping 0.8% Chance a Forest will grow on a tile adjacent to a Forest Preserve. So after making a Forest Preserve - which is by the way awaiable rather late in the game - you will have to wait on average 125 turns for a forest to grow on a given adjacent plot.




Actually, the math is a little more complex than simply multiplying things like you did. It's a binomial distribution. And a 0.8% probability works out to a 50% chance of getting a forest to grow within 87 turns. (There's no guarantee it will ever grow, even after a thousand turns.)

If you have a road on the square, then the probability is cut in half, so 0.4%. that will take 173 turns for a 50% chance of getting a new forest to grow.

As luck would have it I was just investigating forest preserves today...and up pops this thread!

I ran the math for a city I was considering 'preserving' and found somewhat different values than the OP. So for completeness here is what I found.

For just adjacent forests

# adjacent Expected Chance of no growth after
forests Turns 100 turns 200 turns
1 693 90% 82%
2 347 82% 67%
3 231 74% 55%
4 173 67% 45%

For adjacent preserved forests

# adjacent Expected Chance of no growth after
preserves Turns 100 turns 200 turns
1 87 45% 20%
2 43 20% 4%
3 29 9% 0.75%
4 22 4% 0.15%


Where...Expected turns is the actual turn on which the chance of no growth drops below 50%.
All probabilities were computed using the formula (1-chance of growth)^(number of turns). So, for example, with two preserves the chance of growth each turn is 1.6%, so the chance of no growth after 100 turns is 0.984^100 = 0.1993 or roughly 20%.
As you can see the preserves do significantly increase the growth chances but growth is by no means a certainty.
Incidentally I could not see any scaling for game speed in the SDK so I guess on marathon national parks are a lot more attractive.
Jungles are twice as likely to spread as forests so for example, 4 preserved jungles influencing a plot results in an average 11 turns before growth.

The Preserve improvement has only one value that determines the growth of the feature which it is on <iFeatureGrowth>64</iFeatureGrowth>
so there will be no difference between a preserved jungle and a preserved forest. However, the unpreserved jungle spreads twice as often naturally as the unpreserved forest (16 vs 8).

It's too bad there can't be an 'official' CFC mod that incorporates this and other changes that so many of us feel should be in the game. I always hate playing mods that make me feel like I'm playing a completely different game from everyone else, but everyone seems to think forests are broken so maybe a solution could be adopted universally. Sort of like Bhruic's and Solver's patches... but meant to enhance crappy features rather than fixing broken ones. Thoughts?

It is a nice idea, but....

I think it would be extremely hard to get a team of good modders working on it. Most of the changes that we talk in here require extensive SDK changes ( not all ,though... some of them are not much more than XML fine tuning ) and it would not be a very atracting project.

Other problem is we would need to agree in what we would include :lol: Given the sometimes acrimonious nature of some debates, that could prove harder than it looks ;)

The Preserve improvement has only one value that determines the growth of the feature which it is on <iFeatureGrowth>64</iFeatureGrowth>
so there will be no difference between a preserved jungle and a preserved forest. However, the unpreserved jungle spreads twice as often naturally as the unpreserved forest (16 vs 8).
Thanks for the correction.
I was actually aware of the difference and then I still used the preserve numbers as the example, doh! :blush:

No you were dreaming

When I first heard of Forest Preserves, I thought they would be far better... my ideal would be

1. Build a Preserve on ANY plains or grassland (or tundra?) tile
2. IF it has no Forest/Jungle but is adjacent to a Forest, you can work it for 30-50 turns (like a cottage) and at that point it will automatically acquire the Forest
3. IF it has no Forest/Jungle but is grassland and adjacent to a Jungle, you can work it for 10-20 turns (like a cottage) and at that point it will automatically acquire the Jungle
4. It would give bonuses (happy/national park specialist) only if it was a Jungle/Forest Preserve (with some extra bonuses for a Jungle Preserve like +food and commerce.. once you had ecology... maybe even more if it was on a resource that goes obsolete like Ivory or Fur.. the only ones it could get AI put on)

But they really limited it

That's a very interesting idea. I thought sometimes about how we could avoid exploits with forest growing, but perhaps you have it here: instead of paying worker turns, we should pay citizen turns ! So that you would have to pay X turns of working a 2 food tile (grassland + "forest growing" improvement) instead of working a 2 food 1 hammer tile (grassland forest) to be able to gain a forest.

Of course we should have to balance it so that an exploit wouldn't be possible, but I really like the idea. I'll try to take a look at it if I find some time for it :)

well realistically it would be 3 Grassland "Preserves" v. Grassland Farm+2 Workshops = 6 hammer total

and if it was minimum 20 turns... that means it would cost you 120 base hammers to get 3 forests... and those 3 forsts only get you 90 base hammers

Of course the Global warming gives an additional benefit.

Would be nice if you could turn jungle into forest.

Well It would probably be b etter if you could get Jungle to give a benefit... say Jungle+ Preserve gives +1 food +3 commerce (net so the Preserve gives +2 food 3 commerce when on a Jungle to cancel out the Jungles -1)