CLB Journal

Fall 2009

The South-Central Texas Drought of 2008-2009

In the fall of 2007, central and south Texas entered a drought that would become recognized as the second worst drought on record. Statewide, this drought will likely be the driest ever in terms of rainfall. “The drought of 1956 was of longer duration but its intensity was not as extreme”, reads the most recent report by the Office of the State Climatologist. During the summer of 2009, Austin, Texas was one day away from breaking the record for the most days in a year over 100 degrees. The record is 69 days set in 1925. That equates to about 20% of the year over triple digits.

This is the Pedernales River almost completely dry.

Throughout central Texas, lake levels were about as low as they have ever been; rivers and creeks no longer flowed; groundwater supplies dwindled dangerously; some residential and municipal wells ran dry; almost all wildlife suffered as their food and water supplies succumbed to the heat stress.

Pictured here are the singed, upward turned leaves of an Ashe juniper tree.

Here at the Browning Ranch, 31 inches of rain per year is our historical average. During my seven years on the ranch, I have observed years with as much as 50 inches and as little as 20 inches. During the last 23 months, our rain gauges have collected less than 23 inches of rain.

The historical droughts of central Texas are indicated by those years that received less than 20 inches of precipitation. Also shown is the 3.6 degrees F rise in average temperature per decade, especially in the last two decades.

Historically, the drought of 1955 through 1956 in Texas is referred to as the ‘drought of record’. Elmer Kelton writes in The Time It Never Rained “During the long Texas drought of the 1950s a joke - probably already as old as the state - was told again and again about a man who bet several of his friends that it would never rain again, and collected from two of them”.

Ranchers that survived this drought were regarded as heroes for their endurance. The tools of their trade that they had to invent or re-invent in order to survive these times are still commonly used today. Kelton mentions how Mexican cart men burned the thorns off of prickly pear cactus to feed their oxen, and how modern-day ranchers streamlined this process through the invention of butane flamethrowers called ‘pear burner’. This is the tool that I use today in our juniper thinning activities to ignite piles of brush.

This picture is from the Baylor University - Texas Collection and shows a ranch hand burning the tines off of cactus so that the cattle can eat them.

Not only do droughts define our culture, they also define the landscapes we live on. Grass will eventually come to dominate dry-land environments due mainly to their ability to quickly go dormant and rely on energy stored below-ground in its root systems. Trees on the other hand, seldom fair well in drought times since they are slow to go dormant and therefore exposed to the intense heat that often accompanies drought.

This Live oak was located on our western plateau on a west facing slope where the sun’s intensity is greatest.

Each day this summer brought the sight on a newly dead tree. My guess is that central Texas lost millions of trees during this drought. Though it may not initially seem so, this is good news for the grasslands, wildlife, and humans of the Texas Hill Country.

Ashe juniper control free of charge.

In central Texas, we who are land stewards commonly call ourselves ‘grass farmers’. All life in our Texas Hill Country relies on healthy grasslands to provide food for cattle (ranching); food for wildlife (eco-tourism); food for humans (farming). Here at the Browning Ranch, my role as land steward is to rejuvenate the grasslands because we know that they are essential to the central Texas ecosystem and water cycle. Ashe junipers, a native evergreen species, are overtaking our grasslands because they have not been controlled by either fire or drought for over fifty years. I mentioned in my previous discussion, After the Rain, a Good Fire - (Spring 2009), that fire, drought, and grazing are the three historical disturbances that create and maintain grasslands worldwide. Drought is the most uniform, needless to say the cheapest, of the three.

This is a picture of a dying Texas persimmon and Ashe juniper in grassland. The survival for shrubby plants such as these is often based on their proximity to taller shady vegetation. These two grew out in the open and were quickly scorched.

Clean drinking water for humans and wildlife depend on how well our grasslands are functioning. Grass roots enable rainwater to infiltrate the soil layers and move into the limestone strata below, filtering the water in the process. Large openings in this matrix are called aquifers where water is collected and stored. In other words, the limestone hills act like a sponge. When no more water can be absorbed, it will enter a creek or river channel through a seep or spring. These creeks and rivers recharge the aquifers and reservoirs of the Hill Country, and are the main source of Austin’s and San Antonio’s water supply. The capability of the grasslands in the Hill Country to absorb rainfall is a critical component - the most critical in determining the amount of water available to these two cities.

Grasslands compete more with trees and shrubs than they do with climate. The region-wide drought had a controlling influence on the spread of woody plants. This is a benefit to the grasslands now that more sunlight will reach the soil layer. Grasslands expand by occupying surrounding areas void of vegetation with suitable soils. The amount of land available for the grasses to expand has increased as a result of the dying off of the woody vegetation. The newly dead trees will decompose and eventually provide the fungal nutrients that most Texas Hill County grasslands lack. Toppled dead trees help to slow down soil erosion by creating obstructions to run-off with their branches. Standing dead trees will attract wildlife, especially small mammals and insects that help to spread and plant the grass seeds.

Picture here are sprigs of Little bluestem that are still alive due to their energy reserves underground. Notice the decomposing hardwood material surrounding the grasses. This mulch will eventually provide nutrients and organic matter for the grassland.

While none of us want to see our stately Live oaks around our homesteads fall to the drought, or to loose any trees that we may have planted, we are reminded with the loss of every tree that this is indeed grass country. Periodic droughts perpetuate this plant community on regional scales. Central and South Texas got a full dose of this treatment during the drought of 2008-2009. Anything that depends upon the grasslands of the Texas Hill Country is all the better for it.

Scott Gardner
September, 2009