Both Physical and chemical changes.
Fungus aren’t plants
Also this is what I found in the internet: „Ferns are plants. They look quite similar with lichens (e.g. Lobaria sp.) and like fungi, they bear spores underneath the fronds. However, ferns do not get nourishment from decaying matter ( some fungi species does) but undergoes photosynthesis like other plants.“
K₂SO₄ + CaI₂ → CaSO₄ + KI
K: 2 K: 1
S: 1 S: 1
O: 4 O: 4
Ca: 1 Ca: 1
I: 2 I: 1
↓
K₂SO₄ + CaI₂ → CaSO₄ + 2KI
K: 2 K: 2
S: 1 S: 1
O: 4 O: 4
Ca: 1 Ca: 1
I: 2 I: 2