Grasslands are everywhere

From the vast savannas of Sub-Saharan Africa to the wide prairies of North America and the cooler steppe regions, grasslands cover nearly 40 percent of the planet’s land surface. These ecosystems support an incredible variety of wildlife, plants, microorganisms, and human societies, all connected through complex relationships that help maintain life and ecological balance.

Although grasslands may appear simple at first glance, they are among the most important ecosystems on Earth. Here are four fascinating facts about these remarkable landscapes.

Grasses Exist Almost Everywhere

Grasslands and grasses can be found on every continent, thriving in environments ranging from frozen Arctic tundra and mountain alpine regions to tropical savannas, deserts, salt flats, and high-elevation landscapes.

The grass family is one of the most diverse plant groups on Earth, containing more than 11,500 officially recognized species. Some researchers believe the actual number may be closer to 13,000 species.

Grasses play an essential role in human life. Many important crops belong to this family, including wheat, rice, barley, rye, oats, millet, sorghum, sugarcane, corn, and teff. These plants provide basic foods for billions of people and are also used to create many popular drinks around the world.

Beyond agriculture, grasses support wildlife and livestock by providing natural food sources. Bamboo, which may come as a surprise, is also a type of grass. Its strong woody stems are used for construction and decoration, while animals such as giant pandas depend on its young shoots as a major food source.

Many grasses are also planted as lawns and ornamental plants, while others contribute to biofuel production and paper manufacturing.

Scientists at the Smithsonian National Museum of Natural History and research institutions worldwide continue studying grass species, their evolution, and their ecological importance to better understand how these plants influence global ecosystems.

Grasslands and Bison Have a Natural Connection

A major example of the relationship between grasslands and animals can be seen with North American bison. A recent study published in 2022 showed that restoring bison populations on Indigenous lands in the Northern Great Plains can help rebuild prairie ecosystems while supporting food security and traditional food practices among Native Nations.

Historically, more than 30 million bison traveled across North America. These animals provided essential resources, including meat and hides, and played a central role in the economies and cultures of many Plains Indigenous communities.

During the late 1800s, large-scale hunting campaigns drastically reduced bison numbers. By the end of that century, fewer than 1,000 bison remained. The disappearance of this important resource severely affected Plains Indian societies and contributed to their forced relocation onto reservations.

Bison were also vital to maintaining healthy prairie environments. As large grazing animals, they shaped the landscape through feeding, trampling vegetation, and creating wallows by rolling in the soil. These activities increased habitat diversity and benefited many other prairie species, including prairie dogs and pronghorn.

Today, conservation programs, including efforts involving the Smithsonian and Native Nations, have helped increase bison numbers across the Great Plains to around 400,000 animals.

Beyond restoring an important cultural food source, bison also contribute to ecosystem health. Compared with cattle, bison are better adapted to many environmental conditions. They can tolerate extreme heat and respond to drought by changing their diets and reducing body weight. They also require shade and water less frequently than cattle.

With thoughtful management, bison can continue serving both as an important resource for Indigenous communities and as a key part of a thriving prairie ecosystem.

Grasslands Are Strong but Not Invincible

Grasslands have supported humans and countless other species since the earliest Homo sapiens appeared in Africa roughly 300,000 years ago. However, these ecosystems are now experiencing major changes caused by climate change, pollution, and other human-driven environmental pressures.

Researchers from the Smithsonian Environmental Research Center conducted a large-scale analysis of studies examining how grassland plants respond to global changes. Their findings showed that grasslands are remarkably resistant, but only up to a certain point.

In these experiments, grasslands were exposed to different environmental stresses, including rising carbon dioxide levels and increased temperatures. For about the first decade, many grasslands were able to withstand these pressures with little visible change.

After approximately 10 years, however, plant communities began to transform. In some cases, the total number of plant species remained stable, but the actual species present changed dramatically. Some areas experienced nearly complete replacement of their original plant communities.

Kim Komatsu, a former senior scientist at the Smithsonian Environmental Research Center and lead author of the research, explained that grasslands are changing slowly enough that humans still have opportunities to prevent severe future impacts.

However, climate change is accelerating faster than many experimental conditions. Changes predicted by scientists are increasingly appearing naturally across real-world grassland environments.

Grasslands and Fences Often Conflict

The idea that “good fences make good neighbors” does not always apply to wildlife living in African savannas. For white-bearded wildebeest in Kenya and Tanzania, fences can create serious challenges.

Wildebeest are considered a keystone species because they influence many aspects of savanna ecology. They are also central to tourism, attracting hundreds of thousands of visitors each year who come to witness their famous seasonal migrations.

However, expanding human land ownership has led to the construction of fences throughout parts of Kenya. These barriers divide habitats and restrict the natural movement patterns of animals.

This problem is especially serious in environments where water is limited and animals must travel long distances to find seasonal sources of food. Since wildebeest depend primarily on grasses for their diet, restricted movement can directly affect their survival.

Through the Smithsonian’s Movement of Life program, the Smithsonian’s National Zoo and Conservation Biology Institute works with international partners to study wildebeest movements using GPS tracking technology and drones.

By understanding how fences and other threats influence animal behavior, researchers hope to develop better conservation strategies. These efforts can help restore migration routes, protect wildebeest populations, and preserve the wider savanna ecosystem that depends on them.