The plant family Poaceae, commonly known as grasses, is arguably the most economically and ecologically important group of plants on Earth. Comprising approximately 12,000 species, this family includes all cereal grains, bamboos, and turfgrasses. Grasses are found on every continent, dominating biomes like savannas and prairies, which cover around 41% of the world’s land surface. Beyond ornamental lawns, grasses sustain global food production, stabilize ecosystems, and provide raw materials for industry.
Ecological Foundations
The dense, fibrous root systems of grasses provide a foundational ecological service by preventing the loss of surface soil. These networks bind soil particles together, effectively controlling erosion, particularly in open grasslands and along waterways. This structural stability reduces runoff and improves water infiltration, allowing more moisture to soak into the ground.
Grasslands function as significant carbon sinks, storing vast amounts of carbon primarily beneath the surface. Unlike forests, which hold most carbon in above-ground biomass, grasses channel carbon dioxide captured through photosynthesis into their deep, extensive roots. Native prairie species can develop root systems up to 15 feet deep. The continuous annual turnover of root tissue contributes stable organic matter deep into the soil profile, making grasslands resilient to disturbances like fire or grazing.
These expansive, root-bound ecosystems create specialized habitats for countless species of insects, birds, and grazing animals. Grasslands support biodiversity by providing food and shelter within their complex structure of low-lying vegetation. The improved soil health and water retention facilitated by grasses also create conditions for diverse microbial communities and other plant life.
Global Food and Feed Systems
The Poaceae family is the single most important source of food for the human population, as it includes all the world’s major cereal grains. Rice, wheat, and maize (corn) alone contribute over half of all dietary energy consumed globally. Rice provides approximately 20% of the world’s dietary energy, wheat supplies another 20%, and maize contributes about 5.5%.
These grains are cultivated primarily for their energy-rich seeds, which are staples for billions of people. The cultivation of these cereal grasses formed the foundation of many early civilizations, enabling the shift from hunter-gatherer to agricultural societies. Other grass grains like barley, oats, and millet are also important food sources and ingredients worldwide.
Grass is also the foundational feed source for livestock, sustaining the global meat and dairy industries. Forage grasses are grown for pasture grazing, or harvested, dried, and stored as hay and silage for non-growing seasons. Furthermore, the grass Saccharum officinarum, or sugarcane, is a major industrial crop, supplying the majority of the world’s refined sugar and molasses.
Non-Food Industrial and Practical Applications
Beyond food production, grasses are utilized in various industrial and practical applications. The Poaceae family is a source for biofuels, primarily through the conversion of starch-rich crops like maize into ethanol. Dedicated energy crops such as switchgrass (Panicum virgatum) are also being developed for biomass energy production due to their high yield and low input requirements.
The woody stems of giant grasses, particularly bamboo, are used extensively as sustainable building and craft materials. Bamboo possesses a strength-to-weight ratio comparable to timber, making it suitable for scaffolding, flooring, furniture, and construction. Its fibers are also processed into pulp for paper and textiles, offering an environmentally conscious alternative to traditional materials.
Various grasses are used for architectural purposes, such as thatch for roofing, which provides natural insulation. Turfgrass is cultivated for recreational and aesthetic purposes, creating surfaces for sports fields, golf courses, and managed lawns. These managed green spaces offer functional benefits, including surface cooling through evapotranspiration and providing a durable surface for human activity.