The substance, base, or nutrient on which, or the medium in which, a fixed organism is attached. Substrate types include soil, rocks, water, and leaf tissues.
(refers to the size and characteristic of the substrate)
Rounded stone slabs over 10 inches (256 mm) in diameter or length. Boulder slabs are somewhat flattened, as compared with boulders, which are rounded on all sides.
Rounded stones over 10 inches (256 mm) in diameter. They differ from boulder slabs in that they are not flattened.
Stones ranging between 2 1/2 - 10 inches (64-256 mm) in diameter.
Mixture of rounded coarse material from 1/2 - 2 1/2 inches (2-64 mm) in diameter.
Materials 0.06 - 2.0 mm in diameter. Sand has a gritty texture when rubbed between fingers.
Particles ranging from 0.004 to 0.06 mm in diameter. Silt is fine-grained material which typically feels greasy when rubbed between your fingers.
Black, fine, clot-like masses, completely decomposed organic (once living) matter. Note: "muck" does not include sewage sludge.
Particles less than 0.004 mm in diameter, usually clay, which forms a dense, gummy surface that is difficult to penetrate.
Solid rock forming a continuous surface. For purposes of the QHEI, bedrock can be of any lithology.
Dead, unconsolidated organic (once living) material covering the bottom. This could include sticks, wood and other partially or undecayed coarse plant material.
Substrates such as rock baskets, gabions, bricks, trash, concrete, etc., placed in the stream for reasons other than helping the surrounding habitat. The main reason for artificial substrates is to prevent bank erosion.
