Sandy Loam 26-33" PZ

Description

The reference plant community for the Sandy Loam ecological site is a Tallgrass/Midgrass Savanna Community. Historically, the plant community consisted primarily of tallgrasses with a significant component of midgrasses, an abundance of forbs, and individual trees and shrubs or oak mottes distributed throughout the landscape. Little bluestem is the dominant grass with a significant amount of other tallgrasses. Midgrasses and a wide variety of forbs are also a significant component of the plant community. Trees and shrubs are also scattered across the landscape. Annual production ranges from 2800 to 6000 pounds per acre.

In the Little Bluestem Dominant Community, little bluestem totally dominates the site as other tallgrasses decrease and their presence is significantly reduced. Little bluestem becomes very dominant and may comprise as much as 60% of the total plant community in this phase. Sideoats grama also tends to increase somewhat in this initial stage of retrogression. Species composition of forbs, shrubs, and trees generally remains static in this phase. Annual production ranges from 2400 to 5200 pounds per acre.

In the Midgrass Community, tallgrasses such as Indiangrass, big bluestem, and switchgrass are almost completely eliminated from the site, but remnant populations and widely scattered individual plants remain in protected areas. They are often unnoticed because they are grazed very short, are in low vigor, and are not prominent on the site. Little bluestem and sideoats grama begin to decrease in abundance and production. Western ragweed, broomweed, and annual forbs begin to replace more desirable perennial forbs. Mesquite, pricklypear, tasajillo, juniper, and greenbriar begin to increase in density or invade from adjacent sites. Annual production ranges from 2000 to 3600 pounds per acre.

Dominant plant species

1. post oak (Quercus stellata), tree

2. little bluestem (Schizachyrium scoparium), grass

Submodel

Description

The Shortgrass/Forbs Community is dominated by shortgrasses and midgrasses such as buffalograss, curlymesquite, threeawns, silver bluestem, dropseeds, and tumble windmillgrass. Western ragweed and broomweed are the dominant forbs. Tallgrass species and many of the more desirable midgrass species no longer exist in sufficient amounts to allow the site to recover through management alone. Annual production ranges from 1000 to 2000 pounds per acre.

Dominant plant species

1. post oak (Quercus stellata), tree

2. buffalograss (Bouteloua dactyloides), grass

3. silver beardgrass (Bothriochloa laguroides), grass

Submodel

Description

In the Shrubland Community, annual forbs and grasses increase, while brush species such as mesquite, lotebush, pricklypear, and tasajillo become well established and therefore eventually developing a canopy of more than 20% on the site. It should also be noted that for areas never having any brush work, yet have been overgrazed and not burned, develop a different composition of brush than ones having brush control. These areas usually have post oaks, and low growing shrubs such as skunkbush, greenbriars, catclaws and elbowbush. Annual production ranges from 1000 to 2000 pounds per acre.

Dominant plant species

1. post oak (Quercus stellata), tree

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

3. honey mesquite (Prosopis glandulosa var. glandulosa), shrub

4. lotebush (Ziziphus obtusifolia), shrub

Submodel

Description

Hundreds of thousands of acres have been plowed up and converted to cropland, pastureland, or hayland. This community is known as the Converted Land Community. Wheat is the primary annual crop. Bermudagrass is the primary introduced pasture species used in this area.

Abandoned croplands and reseeded areas tend to revert back to a more natural state through the process of secondary succession. This is a very slow process that takes decades or centuries to evolve, dependent on the status of the area at the time it is abandoned. The first plants to establish are “pioneer plants” (annual forbs and grasses followed by early successional shortgrasses and midgrasses). This community is known as the Abandoned Land Community.

Dominant plant species

1. Bermudagrass (Cynodon dactylon), grass

Submodel