The importance of Poaceae in nature and human life

Poaceae (Gramineae) includes 700 genera and 11,000 species in the world. In Iran, about 136 genera, 485 species, 32 subspecies and 59 varieties from this family have been reported, of which 26 taxa are endemic to Iran. The genera Bromus, Stipa, Festuca and Agropyron have the highest share in Iranian rangelands. The genus Stipa with 20 species is one of the most important genera of this family in Iran. This family is the most important family of flowering plants in terms of geographic distribution, ecology and economics. The grains of Gramineae family directly contribute 60% of the human food consumption and indirectly about 20% of the world's protein diet. The most important weeds of the world belong to this family. Grasslands cover about 37% of land, and the livelihood of about one billion people from developing countries depends on them. Because of the importance of feeding livestock from meadows and grasslands, the United Nations considers the identification of them as a solution to the challenge of nutrition in the growing world population in the future. In a grassland ecosystem, only about 20% of the species belong to the Gramineae family, but the same number can produce about 90% of the total biomass. About 16% of rangelands have already been destroyed or turned into agricultural land. The restoration of degraded lands (including grasslands) is one of the biggest potential for reducing greenhouse gas emissions in the agricultural sector. Management of rangeland grazing can play a key role in reducing additional carbon.