@Scarifar Physically touching the trees have no effect. The grass acts as shards of glass to all but the Acalyians, so be sure to wear protective footwear. Seriously, put a poorly protected foot onto a patch of grass in this forest, and the grass will go through your foot.
The real danger to living creature's is the air itself, which contains spores that once breathed in turns loving creature into Acalyian Sentinels, whose details are under the flowers info.
The trees grow like normal trees... but the spores are thr payload. They're carried on the wind and where they touch any Flora, they will convert it into crystal, and that plant will become an Acalyian plant and make it own spores and so forth...
In other words, expect an outbreak of these forests in spots near you!
Also, that city wasn't in the Firewind desert, it was just one city in Amestris. And that level of damage isn't just to one city alone, it was caused by one Realta. And that catastrophe is being replicated 3333 times across the planet. In other words...
Niciel is gonna be noticing a helluva lot more than one city.