Definition: A mixed forest biome is a forest biome which contains densely packed populations or communities of broadleaf and coniferous trees, strongly limiting light penetration to the forest floor.
Definition: A group of hydrous aluminium phyllosilicate (phyllosilicates being a subgroup of silicate minerals) minerals (see clay minerals), that are typically less than 2micrometres in diameter. Clay consists of a variety of phyllosilicate minerals rich in silicon and aluminium oxides and hydroxides which include variable amounts of structural water.