Before revision: Midreaches (Stream order 4-6) In the midreaches of a river, river structures such as rocks and trees play an important role as a supplier of organic material such as periphyton and other autochthonous (see limnology section of link) organic materials.
After revision: Midreaches (Stream order 4-6) In the midreaches of a river, river structures such as rocks and trees play an important role as a supplier of organic material such as periphyton and other autochthonous organic materials.