What makes prairies

This natural-community connection is one very important reason for prairie and savanna conservation. With a little practice, you can learn to recognize the distinctive look of a prairie even from the road. In the hot middle of summer, prairies will be green and streaked with the colors and textures of their many different grasses and wildflowers.

Savannas have many of the same plant species as prairies, but with their scattered trees, they have a parklike look. They often occur as openings in woodlands or on cool, moist slopes amid prairieland. Why are prairies and savannas where they are? What makes them? As with all habitat types, it takes a combination of factors. This eastern reach of the Great Plains has the tallest grasses. As you move westward, the average size of the grasses decreases.

The main difference is moisture: our climate is wetter, supporting more and taller vegetation than the drier lands to our west. Moving east across America, as moisture increases, the grasslands eventually transform into wooded areas, typical of the eastern United States.

Missouri is part of a transition zone, and our natural habitats range from virtually treeless prairie through true forest, which is percent covered by tree canopy. A complex patchwork of intermediate habitats — savannas, glades, and woodlands — form the transition zones between the two extremes, based on varying soil depths, rock types, elevation, slope, angle to the sun, water drainage patterns, and so on. With the amount of moisture available in Missouri, much of the state's landscape, if left alone, would eventually turn into forest.

First the cedars, sumacs, honey locusts, and other pioneer tree species appear. Then oaks, hickories, maples, and other slower-growing trees eventually take over. However, for thousands of years — since about the end of the last ice age — both natural and human-caused disturbances have kept tallgrass prairies open.

Native grasses are adapted to grazing by the American bison, also known as buffalo, and the grazing and trampling by former vast herds of these animals played a role in keeping wooded plants from becoming established.

But fire is the most important factor in the long-term maintenance of prairies, savannas, and woodlands. Native Americans long ago learned to manage grasslands for buffalo by using fire. Perhaps they learned to do this by observing prairie fires that had been started accidentally from a campfire, or by a lightning strike, and noting the effects it had. Native Americans also knew that burning the grasses during the dormant season made travel and hunting easier.

It also stimulated the plants to produce new growth, which was good for the grazing animals they hunted. Burning grasses on purpose also created open, low-fuel areas less likely to catch fire near habitations. For thousands of years, fire kept the prairies from becoming wooded. The species that live on native prairie lands are adapted to occasional fires. Savannas developed on areas near prairies where trees were able to make a toehold and remain — on slopes facing northeast, where it was slightly moister and cooler, for example.

Even though fires occasionally sweep through savannas and kill young wooded plants, a handful of trees survive to reach a size that enables them to withstand the fires. Woodlands, too, experience fires that reduce the understory of small woody trees and shrubs, maintain a grassy ground cover, and fail to eliminate the largest trees. Many plants and animals that live in open, sunny, grassy areas can live in both altered and native grasslands.

Wide-ranging animals like mammals, birds, and insects often can move about among various open, grassy habitats. Examples of animals that can live in almost any grassy, open area include black-and-yellow garden spider, differential grasshopper, great spangled fritillary butterfly, dickcissel, bobolink, brown-headed cowbird, scissor-tailed flycatcher, eastern cottontail, and coyote.

But animals that are tied to certain plant species or environmental conditions found only on tallgrass prairies or savannas can survive and thrive only on those natural communities. Many native prairie species are interconnected so closely that the disappearance of one could mean the end of others.

The grassland or prairie crayfish, for instance, builds burrows into the ground that can be 6 feet deep. These burrows give northern crawfish frogs and other animals cool retreats during hot, dry weather.

You cannot download interactives. Extinction is the complete disappearance of a species from Earth. Species go extinct every year, but historically the average rate of extinction has been very slow with a few exceptions. The fossil record reveals five uniquely large mass extinction events during which significant events such as asteroid strikes and volcanic eruptions caused widespread extinctions over relatively short periods of time.

Some scientists think we might have entered our sixth mass extinction event driven largely by human activity. Our planet is dependent on an interconnected system. If we lose one species, how does that impact the whole system? What if we lose hundreds? Help your students understand the gravity of extinction with these classroom resources.

The grassland biome is made up of large open areas of grasses. They are maintained by grazing animals and frequent fires. Types of grasslands include savannas and temperate grasslands. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Photograph by Phil Schermeister. Twitter Facebook Pinterest Google Classroom.

Article Vocabulary. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. Explore these resources to learn more about what happened between and , as immigrants, American Indians, United States citizens, and freed slaves moved west.

A terrestrial ecosystem is a land-based community of organisms and the interactions of biotic and abiotic components in a given area. Examples of terrestrial ecosystems include the tundra, taigas, temperate deciduous forests, tropical rainforests, grasslands, and deserts. The type of terrestrial ecosystem found in a particular place is dependent on the temperature range, the average amount of precipitation received, the soil type, and amount of light it receives.

Use these resources to spark student curiosity in terrestrial ecosystems and discover how different abiotic and biotic factors determine the plants and animals found in a particular place. The American Prairie Reserve is assembling land in northern Montana, with the goal of creating a seamless 3. When they reintroduce bison to the landscape, both the ecosystem and local people benefit. Join our community of educators and receive the latest information on National Geographic's resources for you and your students.

Skip to content. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. Prairies stretch throughout the Great Plains of North America. Photograph by Kyle Moderhak, MyShot. Also called American buffalo. Dust Bowl. Great Depression. Great Plains. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. Last Updated May 10, Media If a media asset is downloadable, a download button appears in the corner of the media viewer.

Text Text on this page is printable and can be used according to our Terms of Service. Interactives Any interactives on this page can only be played while you are visiting our website.

Related Resources. Landforms and Landscapes. View Collection. Unfortunately, summertime drying of the earth's midcontinental regions is also projected, as greater water loss by evapotranspiration is not offset by increased precipitation Gregory et al. Projections vary from slight Seneviratne et al. Elevated aridity has major implications for the Prairies, the driest major region of Canada. Recurrent short-term water deficits drought impact the economy, environment and culture of the Prairies.

Seasonal water deficits occur in all regions of Canada, but only in the Prairies can precipitation cease for more than a month, surface waters disappear for entire seasons, and water deficits persist for a decade or more, putting landscapes at risk of desertification.

Text Version - figure 2. Declining levels of prairie lakes Figure 2 also suggest drying of the prairie environment. Closed-basin lakes are sensitive indicators of hydrological and climatic change van der Kamp and Keir, ; van der Kamp et al. Fluctuations in lake levels can be related to land use and water diversions, but similar patterns for lakes across the Prairies implicate the influence of climate parameters, particularly rising temperatures, changes in the amount of snow Gan, and changes in the intensity of rain Akinremi et al.

The communities and institutions of the Prairies have considerable capacity to take advantage of higher temperatures and minimize the adverse impacts of climate change due to the relative abundance of financial, social and natural capital. Subregional disparities result, however, from strengths and weaknesses with respect to the determinants of adaptive capacity Table 1. There are also key socioeconomic and environmental factors that underlie the vulnerability of the region to climate change.

For example, the Prairies:. When this chapter refers to the prairie ecosystem, the formal designations 'Prairie Ecozone', 'grassland', 'mixed-grass prairie' or 'prairie' lower case are used.

These geographic concepts are defined in the following section, which outlines the environment and economy of the Prairies. Section 2 describes climatic and socioeconomic characteristics that expose the population to current and future climate risks and opportunities. Sections 3 and 4 discuss sensitivities to current climate and key vulnerabilities to climate change with respect to natural capital and socioeconomic sectors. The process of adaptation and the concept of adaptive capacity are discussed in Section 5.

The chapter concludes with a synthesis of the main findings. Alberta, Saskatchewan and Manitoba are roughly equal in area but not in population Table 3. Text Version - figure 3. The Prairies extend west from Hudson Bay to the crest of the Rocky Mountains, thus spanning several major climatic, biogeographic and geological zones and watersheds Figure 3.

Because of the region's mid-latitude location in the rain shadow of the Rocky Mountains, the climate is generally cold and subhumid. There are extreme differences in seasonal temperatures.