HABITAT & RANGELAND RESEARCH
Ecology, Harvest Factors, and Population Data of Ocotillo in the Trans-Pecos Region of Texas
The visually striking and biologically important species ocotillo (Fouqeieria spendens) is a signature of the desert southwest landscape. Most of the time, ocotillo are seen as a collection of many wand-like branches reaching skyward from a short base. However, immediately following a spring or summer rain, the branches transform with a crop of vibrant green leaves that will again drop when water becomes less available. This efficient mechanism allows them to survive in the harsh, arid environment.
Unlike other plants, ocotillo produce several crops of leaves each year in response to rainfall patterns.
For centuries, ocotillo has been used by humans to make living fences, walls and corrals, and today, in the United States, ocotillo plants are wild harvested and marketed as ornamental plants in arid southwest cities. Their slow growth, and long lives (some can live to be over 150 years old!), combined with a growing interest in conserving water by using desert plants in landscaping, has led to a lucrative market for ocotillo. A research group called TRAFFIC North America found that between 1998 and 2001, west Texas supplied nearly 100,000 wild-harvested desert plants valued at about $3 million, of which ocotillo comprised 67%, to the southwestern United States. This highlighted the need and prompted researchers with Borderlands Research Institute to investigate the ecology, harvest factors, and population characteristics of ocotillo in west Texas.
Ocotillo stands were mapped and baseline data were collected from ocotillo plants along 21 belt transects on private lands in the Chihuahuan desert of west Texas. We measured basal width, density, height, nodes on longest branch (which can be used as a rough age estimate), number of branches, and width at breast height of 325 individual plants. Heights ranged from less than 6 inches to over 26 feet tall, and the average plant height was 7.75 feet.
On the ranch where this research was conducted, we mapped 464 ocotillo stands, of which 47 percent were inaccessible to vehicles. Another 19 percent of the population did not have ideal harvest factors, which leaves the remaining 34 percent of the population available for potential harvest. We also collected seeds along a random transect from plants of different height classes to determine differences in production, and tested germination success at different seed depths. This seed viability data will aid in making sound management decisions when determining sustainable harvest rates. The results of this research will benefit the conservation and sustainable use of ocotillo as a resource, and help develop techniques for improving land management for wild-harvested species.