What Pioneer species break down rocks forming the beginning of?

Pioneer species, such as lichens and certain mosses, play a crucial role in breaking down rocks and initiating soil formation. They secrete acids that help weather the rock surface, gradually breaking it down into finer particles. Over time, their decomposition adds organic matter to the developing soil, creating a more hospitable environment for subsequent plant species. This process is essential for ecological succession and the establishment of more complex ecosystems.