Texas Ecoregions

Question 1

How many ecoregions are there in Texas?

Answer 1

10

Question 2

Which ecoregion is characterized by rolling terrain covered with pines and oaks, and rich bottomlands with tall
hardwoods?

Answer 2

East Texas Pineywoods

Question 3

What is the average annual rainfall in the East Texas Pineywoods?

Answer 3

36 to 50 inches

Question 4

What kinds of soils are present in the East Texas Pineywoods?

Answer 4

Generally acidic and mostly pale to dark gray sands or sandy loams

Question 5

Which ecoregion is a near level, slowly drained plain less than 150 feet in elevation, dissected by streams and rivers flowing into the Gulf of Mexico?

Answer 5

Gulf Coast Prairies and Marshes

Question 6

Which ecoregion includes barrier islands along the coast, salt grass marshes surrounding bays and estuaries, remnant tallgrass prairies, oak savannahs, and live oak mottes scattered along the coast, and tall woodlands in the river bottomlands?

Answer 6

Gulf Coast Prairies and Marshes

Question 6

What is the average annual rainfall for Gulf Coast Prairies and Marshes?

Answer 6

30 to 50 inches

Question 7

In this ecoregion, native vegetation consists of tallgrass prairies and live oak woodlands. Brush species such as mesquite and acacias are more common now than in the past. The region provides important habitat for migratory birds and spawning
areas for fish and shrimp.

Answer 7

Gulf Coast Prairies and Marshes

Question 8

Which region is a transitional area for many plants and animals whose ranges extend northward into the Great Plains or eastward into the forests?

Answer 8

Post Oak Savannah

Question 9

What is the average annual rainfall for the Post Oak Savannah?

Answer 9

28 to 40 inches

Question 10

In this region, upland soils are light colored, acidic sandy loam or sands. Bottomland soils may be light brown to dark gray and acidic with textures ranging from sandy loams to clays.

Answer 10

Post Oak Savannah

Question 11

This region is named for the deep, fertile black soils that characterize the area.

Answer 11

Blackland Prairie

Question 12

The soils in this region once supported a tallgrass prairie dominated by tall-growing grasses such as big bluestem, little bluestem, Indiangrass and switchgrass. Because of the fertile soils, much of the original prairie has been plowed to produce food and forage crops.

Answer 12

Blackland Prairie

Question 13

What is the annual rainfall in the Blackland Prairie?

Answer 13

28 to 40 inches

Question 14

What kind of soils are typical in the Blackland Prairie?

Answer 14

Soils are uniformly dark colored alkaline clays, interspersed with some gray acidic sandy loams.

Question 15

How did the Cross Timbers ecoregion get its name?

Answer 15

Early travelers through north Texas coined the name “Cross Timbers” by their repeated crossings of these timbered areas that proved to be a barrier to their travel between the open prairies to the east and west.

Question 16

This area in north and central Texas includes areas with high density of trees and irregular plains and prairies. Soils are primarily sandy to loamy.

Answer 16

Cross Timbers

Question 17

This region is characterized by plains of thorny shrubs and trees and scattered patches of palms and subtropical woodlands found in the Rio Grande Valley.

Answer 17

South Texas Plains

Question 18

The plains of this ecoregion were once covered with open grasslands and a scattering of trees, and the valley woodlands were more extensive. Today, the primary vegetation consists of thorny brush such as mesquite, acacia, and prickly pear mixed with areas of grassland.

Answer 18

South Texas Plains

Question 19

How much annual rainfall falls on average in the South Texas Plains?

Answer 19

20 to 32 inches

Question 20

Soils of this region are alkaline to slightly acidic clays and clay loams. The deeper soils support taller brush, such as mesquite
and spiny hackberry, whereas short, dense brush characterizes the shallow caliche soils.

Answer 20

South Texas Plains

Question 21

This ecoregion is commonly called the Texas Hill Country.

Answer 21

Edwards Plateau

Question 22

What is the average rainfall for the Edwards Plateau?

Answer 22

15 to 34 inches

Question 23

In this ecoregion, soils are usually shallow with a variety of surface textures. They are underlain by limestone honeycombed with thousands of caves.

Answer 23

Edwards Plateau

Question 24

This region is characterized by grasslands, juniper/oak
woodlands, and plateau live oak or mesquite savannah.

Answer 24

Edwards Plateau

Question 25

Elevations range from slightly less than 100 feet to over 3,000
feet above sea level in this ecoregion.

Answer 25

Edwards Plateau

Question 26

Several Texas rivers begin in the gently rolling hills and broad flats of this region. These rivers and their numerous tributaries are responsible for the rolling character of the land.

Answer 26

Rolling Plains

Question 27

What is the average annual rainfall in the Rolling Plains?

Answer 27

20 to 28 inches

Question 28

In this ecoregion, soils vary from coarse sands along outwash
terraces adjacent to streams, to tight clays and shales. Soil pH is neutral to slightly alkaline.

Answer 28

Rolling Plains

Question 29

In this ecoregion, the original prairie grasslands included tall and midgrasses such as bluestems and gramas. After being settled, buffalo grass and other short grasses have increased under heavy, uncontrolled grazing. Mesquite is a common invader on all soils.

Answer 29

Rolling Plains

Question 30

Which ecoregion is a relatively level high plateau with elevations ranging from 3,000 to 4,500 feet above sea level?

Answer 30

High Plains

Question 31

What is the average annual rainfall for the High Plains?

Answer 31

15 to 22 inches

Question 32

Which ecoregion is a shortgrass prairie dominated by buffalo grass?

Answer 32

High Plains

Question 33

In this region, pronghorn are still abundant and large flocks of wintering waterfowl still migrate to the playa lakes.

Answer 33

High Plains

Question 34

This region is perhaps the most complex of all the regions. It occupies the extreme western part of the state eastward generally to the Pecos River. This is a region of diverse habitats and vegetation, varying from the desert valleys and plateaus to wooded mountain slopes.

Answer 34

Trans Pecos

Question 35

In this ecoregion, the average annual rainfall is less than 12 inches, making it the driest in Texas.

Answer 35

Trans Pecos

Question 36

In this complex ecoregion, soil surface textures and profile characteristics are varied which generally react alkaline.

Answer 36

Trans Pecos

Question 37

What are the names of the subregions in the Trans Pecos ecoregion?

Answer 37

Sand Hills, Stockton Plateau, Salt Basin, Desert Scrub, Desert Grassland and Mountain Ranges