Dwarf Fortress Bug Tracker - Dwarf Fortress
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0009581Dwarf FortressDwarf Mode -- Environmentpublic2016-02-19 09:362020-02-24 12:50
win 7
0009581: Sparsely forested/vegetated biomes will get lush in some years
This has happened in all my forts since the multi-level trees were introduced. Seems odd that a sand desert or a savanna/grassland with few trees turn into a lush forest with thick vegetation after 4-5 years. I suspect that since caverns always seem to have plenty of trees, unless it is completely barren, it somehow translates to the above ground plant life generation as well. The only exception to the plantlife not to start growing in abundance is that if the biome has no trees at all (mountain, rocky wasteland).
Start a fort in a biome which has sparse vegetation/trees, breach a cavern.
No tags attached.
has duplicate 0011157resolved Loci Maximum number of trees seems absolutely unrelated to the initial amount of trees on the map. 
Issue History
2016-02-19 09:36MuumehNew Issue
2016-02-22 10:29ButtonIssue Monitored: Button
2016-02-22 10:32ButtonNote Added: 0034720
2016-02-22 10:35ButtonNote Edited: 0034720bug_revision_view_page.php?bugnote_id=0034720#r13985
2016-02-22 10:35ButtonNote Edited: 0034720bug_revision_view_page.php?bugnote_id=0034720#r13986
2016-02-22 10:36ButtonNote Edited: 0034720bug_revision_view_page.php?bugnote_id=0034720#r13987
2016-02-22 10:40ButtonNote Edited: 0034720bug_revision_view_page.php?bugnote_id=0034720#r13988
2016-02-22 11:14Sarmatian123Note Added: 0034722
2016-02-22 11:16Sarmatian123Note Edited: 0034722bug_revision_view_page.php?bugnote_id=0034722#r13992
2016-02-22 11:16Sarmatian123Issue Monitored: Sarmatian123
2016-02-22 14:22PatrikLundellNote Added: 0034724
2019-10-06 09:29LociRelationship addedhas duplicate 0011157
2019-10-06 09:31LociNote Added: 0039529
2019-10-06 09:32LociAssigned To => Loci
2019-10-06 09:32LociStatusnew => acknowledged
2019-10-06 09:32LociSummarySparsely forested/vegetated biomes will get lush in some years after a cavern has been breached => Sparsely forested/vegetated biomes will get lush in some years
2020-02-24 12:50FantasticDorfNote Added: 0040188

2016-02-22 10:32   
(edited on: 2016-02-22 10:40)
According to research http://www.bay12forums.com/smf/index.php?topic=153848.msg6624359#msg6624359 [^] , treesplosion isn't triggered by breaching the caverns, but simply by time. Our best guess is that the tree regrowth code is tuned for forests and doesn't differentiate based on biome.

2016-02-22 11:14   
(edited on: 2016-02-22 11:16)
I've started in a mountain region with trees in. Not a jungle I guess. So I can not confirm the surface vegetation issue. Even if it looks like a jungle now. Maybe it should. Maybe it is normal. In mountains you know.

However space inside of my fortress above the ground blew up with huge amounts of cavern underground vermin, every time I breached a new cave. My cats were going crazy into overdrive to cull the vermin down. When I breached last 3rd cave (those are caves created under 42.04 version though) I've got so many of the cave vermin, I had to squash under bridge 3 times full load of my refuse storage, just to get some free space in it. Maybe this issue is somehow connected? Mega spawns of cavern vermin was for sure a major hit on my fps. Good I keep many cats. I would be happy, if this is not a feature, but issue to be fixed. http://dffd.bay12games.com/file.php?id=11787 [^]

Well, there is also some issue with forgotten beasts breeding in caverns too much a bit. Maybe those all 3 different problems are somehow... connected? And not a feature then?

2016-02-22 14:22   
As Button said, it seems saplings are kept in check only by tree canopies. Clean cutting can actually make things worse, because there are no mature trees with large canopies to stop regrowth, so more trees can mature. Very rocky ground provides fewer tiles for saplings, but that only slows things down marginally. Toady intends to eventually revamp the farming/tree/... system with soil quality, soil moisture, nutrients, etc. to control growth and harvest sizes (rain forests will be tricky with that logic, though, since all their nutrients are in the vegetation, not the soil...).

Breaching caverns releases vermin, and they can indeed explode, although it settled down after a while. That's hardly related to trees.

FBs don't breed (they might if two happened to be of the same kind and not hostile). As far as I understand there's one FB per underground "region", and they're generated at world gen. Not related to trees.
2019-10-06 09:31   
v0.44.12: Urist McuristUrist posted an example save in 0011157:

http://dffd.bay12games.com/file.php?id=14551 [^]
2020-02-24 12:50   
Still spotted in 47.02 fort mode, particularly jarring occurances are cold deserts with pre-laid snow in which melted in cracks to ice up then became a natural stagnant muddy pond with toad vermin i had never previously known was there because they were just ramps.

Provided save is timestamped from a clean world-backup of 'The World of Dragons' pre-settling of my fortress with XML's + data, a save during the first embark year where the snow has passed but left the ice pool, and the aftermath the proceeding year 101 with lots of grass, sapling & harvestable over the sparse area and a thriving stagnant pond where there shouldnt be one in the middle of the desert.

(( http://dffd.bay12games.com/file.php?id=14859 [^] ))