Last Wednesday, our class visited the Lubbock Lake Landmark in Lubbock, TX. We got the opportunity to meet Scott Trevey, the historical maintenance supervisor, who talked to us about the significance of the Landmark and the attempts to restore it to its natural state. The Landmark is an archeological and natural history preserve. Throughout its boundaries one encounters numerous archeological sites maintained by Texas Tech University since 1936 when a couple of students discovered an Indian arrow head. Since then, human artifacts have been encountered from more than 12,000 years ago. Apart from its archeological value that site also offers a great view at the natural history of the Southern Plains. The staff of the Landmark have done a great job in restoring much of the natural grasses, plants, trees, and shrubs lost during the poor management of the site by the city of Lubbock. The site has served as a dump and a recreation area for dirt bikes. Human disturbance turned it into a field saturated with invasive and overgrown native plants. Trevey told us how just ten years ago, the site was covered in mesquites. “You could not see past 10 to 20 feet,” he said, “and today look!” Indeed, as one takes a look at the site one is able to capture the sight of a developing prairie.
The control of a species that has overpopulated an area due to the lack of a predator or repressor element is indeed one of my favorite aspects of ecology. As humans, we have introduced many invasive species that over grow and eventually run out native species while changing local ecosystems. However, the Lubbock Lake Landmark was not only invaded by non-native individuals but also, and what makes this more interesting, some of its native species were able to overpopulate the area. The mesquite is native to West Texas, still it has been allowed to take over the prairies that existed (prairies usually contain short and/or tall grasses with the occasional presence of a tree or shrub). Why is this? Well that is a simple answer, the absence of fire. Fire can be considered the sheriff of the prairie. The grasses and trees evolved conjunctly with fire, making it a necessary component to the maintenance of the ecosystem. It all comes down to the location of the plant’s apical meristem, the source of growth. Grasses maintain their apical meristems underground, where they are protected from fire or grazing animals. Trees maintain their apical meristems at the tops of their branches, which exposes this crucial part to damage. Natural fires, thus controlled the spread of trees throughout the grass fields while preserving those plants who where not killed by them.
One can easily picture the Landmark’s previous condition. Surrounding private properties that are engaged in the farmland preservation program remained untouched by farmers or natural processes. Instead, the plants within the property are allowed to grow at their maximum rates. Evidently the mesquite triumphs in these properties, covering most of them in a thick forest. Walking throughout the landmark allows one to see just how damaging human existence can be when it disrupts the ordinary ecosystem development that has existed in an area for many years. It also reveals the hard work that naturalists are having to do in order to revert the damage, and bring back the native species to an area.