- Mosses produces acid from their roots
- Acid can cause rocks to weather by chemical reaction
- So, mosses can cause chemical weathering by producing acid from their roots

So, mosses can cause chemical weathering by producing acid from their roots
Growth and activities of organisms can speed up the chemical weathering of rocks. Which organisms naturally cause most of the chemical weathering of rocks?
- Mosses produces acid from their roots 
- Acid can cause rocks to weather by chemical reaction