Terra preta is characterized by the presence of low-temperature charcoal residues in high concentrations;[1] of high quantities of tiny pottery shards; of organic matter such as plant residues, animal feces, fish and animal bones, and other material; and of nutrients such as nitrogen, phosphorus, calcium, zinc and manganese.[6] Fertile soils such as terra preta show high levels of microorganic activities and other specific characteristics within particular ecosystems.