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0004031Dwarf FortressVegetationpublic2011-02-19 23:382011-12-21 12:33
Toady One 
0004031: Grass does not grow back.
Grass eaten (not trampled) by grazers does not grow back, ever. It just becomes a dead clay tile forever. Using this, I completely decimated an entire map with just three yaks.
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Issue History
2011-02-19 23:38janglurNew Issue
2011-02-20 11:32thadiggaNote Added: 0015335
2011-02-23 12:49Khym ChanurIssue Monitored: Khym Chanur
2011-02-23 20:55Hieronymous AlloyIssue Monitored: Hieronymous Alloy
2011-02-25 02:24KipiNote Added: 0015483
2011-02-25 02:24KipiIssue Monitored: Kipi
2011-02-25 06:46FootkerchiefIssue Monitored: thadigga
2011-02-25 06:46FootkerchiefNote Added: 0015500
2011-02-25 06:59KipiNote Added: 0015501
2011-02-25 16:45janglurNote Added: 0015510
2011-02-28 14:05Toady OneNote Added: 0015582
2011-02-28 14:05Toady OneStatusnew => resolved
2011-02-28 14:05Toady OneFixed in Version => 0.31.20
2011-02-28 14:05Toady OneResolutionopen => fixed
2011-02-28 14:05Toady OneAssigned To => Toady One
2011-02-28 14:07Toady OneNote Edited: 0015582bug_revision_view_page.php?bugnote_id=0015582#r5860
2011-03-03 13:53Khym ChanurIssue End Monitor: Khym Chanur
2011-12-21 12:33KipiIssue End Monitor: Kipi

2011-02-20 11:32   
I think that this is caused by a multi-biome embark with a non-grass biome. Regrowing grass currently gets picked out of one static biome (in your case the non-grass one), not out of the biome the tile is on.
2011-02-25 02:24   
My latest experiment revealed that this problem only occurs aboveground. Any grass that has grown on underground soil (have not tested with caverns yet) do eventually grow back. So, big enough pasture will be able to sustain the animals assigned inside, though the pasture has to be relatively big as the regrowth is quite slow compared to the initial growth rate.
2011-02-25 06:46   
Reminder sent to: janglur, Kipi, thadigga

If you have a save that demonstrates this problem, please upload it to http://dffd.wimbli.com/ [^]
2011-02-25 06:59   
Here is my save:

http://dffd.wimbli.com/file.php?id=3849 [^]

In the old above ground pasture area (northern walled section) the grass does not regrow. In the underground pasture the grass does regrow, though slowly.

The underground pasture can be located west from farms, north from barracks. It's the smallish empty room. The whole floor was grass when I assigned few animals there, and after I removed all the animals and butchered those there pasture had bare soil spots everywhere. Now, after some time, the grass has begun regrowing. I noticed this when I took a screenshot of the pasture after removing the animals, then comparing the picture to the state of the pasture after few seasons. The regrowth of grass was visible.

I have two biomes, other is normal grass biome, the other was desert IIRC. So, one biome with grass, one biome without grass.
2011-02-25 16:45   
I'm the OP, and here's mine.

http://dffd.wimbli.com/file.php?id=3852 [^]
Toady One   
2011-02-28 14:05   
(edited on: 2011-02-28 14:07)
The deserts etc. have a tile flag that makes some of the tiles not have regrow, so that they can retain their half-grass/half-bare appearance without any large-scale calculations. Deserts etc. were also generally broken regrow-wise. Unfortunately, I applied the flag incorrectly, so old saves won't work correctly in the new release. As a result, if you load old saves in 0.31.20, deserts will grass in entirely, but new saves should be fine once the release is up.