FIRE ECOLOGY of the prairies
|
|
Historically, fires occurred frequently in the tallgrass prairie and were essential in maintaining these grasslands. Tallgrass prairies covered parts of Nebraska,Illinois, Iowa and Kansas and extended into the more eastern states in the Midwest. Tallgrass prairie is made up of grasses, forbs,shrubs and trees and is further characterized by relatively moist soils. One benefit of fire in this community is the elimination of invasive plants, thereby helping to shape and maintain the prairie.Across the Great Plains, lightning-caused fires may have occurred as frequently as every 1 to 6 years. |
|
What are other benefits of fire? consider nutrient recycling, decrease in pest populations, others? Having evolved in a grassland environment subjected to frequent fires, big bluestem is well adapted to fire. After aboveground foliage is consumed by fire, new growth is initiated from rhizomes. The well-developed rhizomes are generally 1 to 2 inches (2.5-5 cm) below the soil surface. In general, grassland fires are of low intensity because the flames pass quickly, and the soil temperature 1 inch (2.54 cm) below the surface rises very little. Plants burned during the spring when dormant quickly send up vigorous new growth because of stored carbohydrate reserves in belowground organs.Growth of native species such as big bluestem, little bluestem and Indian grass increases significantly following a fire. Introduced species that initiate growth earlier in the spring and continue growing later in the fall than native species can be placed at a disadvantage by properly timed spring and fall fires (meaning the introduced species do not grow as quickly). If burned during the summer when plants are actively growing, plants normally survive by initiating new growth from rhizomes; however, regrowth may be slower and less vigorous than in plants burned when dormant If fire were excluded, the tallgrass prairie would vanish, and shrubs, trees and exotic grasses would dominate the ecosystem. Before European settlement of the grassland, naturally occurring fire helped to maintain the grasslands. Today many of the prairies that remain are managed by prescribed burns.In most managed prairies, prescribed fire is introduced on a two-to three-year cycle. |
|