Bonus prequisite farms/mines in jungle tiles

[Colon]

I've been looking for simple (XML-based) ways to keep forests and jungles around for longer. One change I've already made is to extend cutting times, and another change I'm considering is to change the prequisite tech from iron working to something relatively modern. However, I still want it to be possible to build improvements in jungle tiles that have a resource with iron working. (I don't want the resources there to be inaccessible for most of the game). Plantations are straightforward (just keep the prerequisite tech unchanged), but mines and farms are trickier. Would I need to create a new improvement in order to exploit the resources that require them, or would be possible to set up existing improvements to that effect?

(sorry for the titlegore)

 

[Dancing Hoskuld]

In the Build Infos file in the xml/units folder you can set bRemove to 0 so that the feature is not removed. eg, have mines not remove the forest. This gives the city the benefits of the forest including the yield from both the forest and the mine.

Is this the sort of thing you mean?

 

[Colon]

I want to change the prerequisite tech for cutting down from iron working to something more modern (rechangeable parts, say). However, I still want to be able to build improvements in those jungle tiles that have resources before I have that prerequisite tech, and only in those jungle tiles. I don't want to be able to build improvements in other jungle tiles. The reason is that I don't want resources in jungle tiles to be locked away for most of the game.
Whether it would be possible to cut down jungles in those tiles with resources or whether an improvement could be build on top of the jungle, either option would be fine, as long it's possible to get to the resources.

 

[Dancing Hoskuld]

The only way I have seen that done is to have two versions of the improvement one where the improvement requires the resource for it to be valid and the other which can only be built after the tech.

Last time I did something like this we had the one that requires the resource upgrade to the one that didn't for tidiness and clarity.

 

[Colon]

Turns out there's already an improvement that will allow access to resources in jungle tiles without cutting these down: the fortress!

 

[The Snug]

I don't remember the xml for lumbermills, which allow mills to be placed on forests without having them get cut down. You could emulate the xml for that.