I don't know if this question is botany or geology or something in between. I got the idea from this island called Pea Patch Island. It gets it's name from an interesting local legend. The story I heard was the island was originally just a mudbank in the Delaware river. It appeared some time in the 18th century and it would've eroded away soon after it appeared But then a ship carrying peas ran aground on the island causing the cargo to spill. The peas mixed in with the soil and sprouted. The roots of the pea plants strengthened the soil, turning Pea Patch Island into a much more permanent land mass. I'm not asking if that's true in the specific case of Pea Patch Island but more generally. Can plant's roots really help temporary land masses become permanent?