Shallow 26-33" PZ

Description

The Midgrass Prairie Community is the interpretive plant community for the site. It was a fire induced midgrass prairie with scattered stands of tallgrasses, scattered woody plants and a good variety of forbs. The tallgrasses usually occurred in the vicinity of limestone outcrops, drainages or the crests of hills. Live oak, hackberry and shrubs were widely scattered in draws. Sideoats grama was the most abundant grass throughout the site. It is estimated that the Midgrass Prairie Community produced from 1500 to 3500 pounds of biomass annually. Grasses make up to 85 percent of species composition.

The Mixed-grass Community (1.2) is mixed-grass dominated grassland being encroached by indigenous or invading woody species. Numerous woody species, including juniper and mesquite, are increasing in density. In this phase, the increasing woody species are generally less than four feet tall and the woody canopy vary between 5 and 20 percent. The prairie becomes grassland being encroached by previously suppressed woody species. The preferred tallgrasses are being replaced by the more grazing resistant midgrasses although little bluestem often persists. Most of the perennial forbs persist, but in lesser amounts, being replaced by weedy forbs. Annual primary production ranges from 1000 to 3000 pounds per acre. Forage production is predominantly grass.

Dominant plant species

1. sideoats grama (Bouteloua curtipendula), grass

2. little bluestem (Schizachyrium scoparium), grass

Submodel

Description

The Mixed-brush/Shortgrass Community (2.1) is characterized by a 20 to 40 percent canopy of woody plants on a shortgrass rangeland. The composition of annual production has shifted toward the woody component. All, except the more palatable woody species, have increased in size and density. Remnants of climax grasses and forbs and unpalatable invaders occupy the open areas between trees and shrubs. Cool-season grasses such as Texas wintergrass can be found under and around woody plants. Annual primary production is approximately 1000 to 2500 pounds per acre.

The Mixed-brush/Shortgrass/Annuals Community (2.2) is open woodland dominated by live oak, mesquite and/or juniper. With continued heavy grazing, the trees and shrubs can approach 70 percent ground cover. Shortgrasses and low quality annual and perennial forbs occupy the woody plant interspaces. Grasses and forbs make up 35 percent or less of the annual forage production. Annual production is 1000 to 2500 pounds per acre.

Dominant plant species

1. Ashe's juniper (Juniperus ashei), tree

2. Texas wintergrass (Nassella leucotricha), grass

Submodel