The landscape and community of the area surrounding the Brackenridge Field Lab (BFL) have been shaped by both human activities and natural events, long before BFL itself was established in the 1960s. Observing the land around BFL in the context of its history allows modern ecologists and their students to better understand the patterns of succession, community structure, and biodiversity that they encounter in the field. Evidence of Native American camps along the stream beds that cut through the property shows that humans have used the land at and around BFL for centuries. However, the known land-use history of this area did not begin until the mid-1800s, when development and industry in Austin approached the banks of the Colorado River.
In 1840, logging and clearing started along the Colorado to make way for farmland and construction projects. Trees were cleared into the early 1860s, and the newly available land was largely converted into pasture. In the 1890s, these fields and farms became neighbors to limestone quarrying operations that left broad swaths of bare rock in juxtaposition to the pastures and patchy woodlands of the area. Only ten years after these quarries were developed, the original dam on the river washed out, and the resulting flood deposited deep silt in the shallow strip of land along the riverbank, now called the River Terrace. At this point, a heterogeneous mixture of habitats was established across the landscape, with limestone cliffs, grassy fields, and riparian areas occurring adjacent to one another. Already, these changes were affecting the local plant community, as illustrated by the colonization of the newly flooded banks by cottonwood trees in the early 1900s, some of which still exist in the lower terrace today.
In the 25 years following the flood, housing was built across the future site for BFL. With houses came landscaping, and by the 1950s several invasive ornamental shrubs and lawn plants, including Chinese and Japanese privet, the chinaberry, and various species of exotic grass, were spreading across the area. While the houses and pastures were abandoned and cleared in the late 1950s, these plants would continue to influence the community and persist in the area even today.
In 1966, the Brackenridge Field Lab was established and enclosed with a high fence. The field station’s artificial ponds, enclosures, roads and lab buildings were built in the following months, and in the fall of 1967, John Crutchfield became Resident Manager of the site. In the first ten years of BFL’s management, the community began to shift again, with cedar elm and hackberry trees encroaching on the old pastures and the mesquite trees that were growing there. The high fence also excluded deer from the property, and in their absence, the exotic plants introduced by the housing development spread unchecked across the site.
In 1980, Lawrence Gilbert assumed directorship over the lab, and new projects to restore the area were initiated. This included the clearing of the firefly meadow in ’81 and an effort to control the invasive chinaberry in ’82. In ’86, clearings were made along the west side of the lower terrace to encourage native prairie, followed by additional grassland restoration in ’89 during which several species were introduced, including Passiflora tenuiloba. Unfortunately, a new invader was making its way across BFL alongside these restoration efforts: the imported fire ant, Solenopsis Invicta. The ant was introduced from the riverbank in 1981, and by 1988, S. invicta had spread across the property and the native ant community, which had been well-documented prior to this invasion, began to decline. Other unexpected events occurred in the mid-80s, including a rabbit population explosion in ’83 and an accidental fire started in the northern experimental garden area in ’84. In the late 1980s, fish tanks were added to the property, creating artificial wetlands that were quickly colonized by cottonwood and willow trees.
After being absent from the property for over 20 years, deer colonized the site in 1990. By the mid-90s, their impact on the vegetation was clear as the understory of the woodlands noticeably thinned and browse lines became conspicuous. Antler rubbing from rutting bucks also killed small trees and possibly contributed to an increased presence of oak wilt that coincided with the arrival of the deer. In the late 90s, drought combined with deer pressure killed many of the hackberry trees at the site and led to the extirpation of the orange tip butterfly. In 2002, the deer at BFL were culled to reduce the stress of their large population on the community, with 37 individuals removed. Deer remained at BFL until the beginning of 2016 when they were extirpated from the lab by a pack of coyotes. Following their disappearance, populations of plants such as passion vine, poison ivy, laurel cherry, and others have begun to recover, although oak wilt has continued to move across the property.
In recent years, more facility improvements have been made including the construction of the tropical greenhouse (1997), aphid greenhouse (2015) and a new well (2017). More projects aimed at invasive species control were implemented and some began to meet with some success. In 2003, phorid flies, which were introduced to control the imported fire ant, became abundant for the first time. In 2014, stands of invasive heavenly bamboo shrubs were cleared by hand, with a similar approach being taken with privet shrubs in the following years. In conjunction with USDA, two biological control agents have been released at BFL to control the giant cane, Arundo Donax. BFL remains a unique site in Texas to study how habitats, plants and animals respond to environmental changes and urban disturbance.
