I didn't post about it cause it was too depressing watching all the plants go down hill. A combination of SO2 gas + acid rain (sulphuric acid) + very little sunlight, meaning very low photosynthesise levels, created havoc with most plants. It started with leaves getting burned along edges, some in middle, curling up, and dropping off. Even some large trees, like the santol, became totally defoliated almost immediately.
The big worry was that this eruption would go on, as the USGS put it, for many months or years or even decades! Fortunately they were wrong. The negative effects were cumulative, so the worry was that a couple more months and most plants would be either dead or beyond recovery.
The amazing thing was once the black eruption plume cloud disappeared, and sunlight came back, almost all plants in ground immediately recovered. The santol, which was totally leafless for 3 months miraculously not only releafed, but started at same time blooming. Heaviest damage were to potted plants, especially the smallest ones. I should have put all potted plants under plastic cover. But i was busy trying to save my house and all my belongings in case of forced evacuation.
Good news is that it seems like some of the most noxious weed trees here, like strawberry guava, suffered the most, and most are dead. The state has been for decades trying to figure out how to get rid of them. Seems like all the myrtaceas are particularly susceptible to SO2. I had to cover some of my rare jaboticabas as they were getting totally defoliated.