Quercus buckleyi (also known as Quercus texana, Quercus shumardii var. texana, Spanish oak, Texas red oak, or Buckley oak), is a common tree of limestone hills of west central Texas. Where mature Buckley oaks occur naturally, one can also find seedling-sized specimens, typically 3 to 13 centimeters tall.
How fast do small Buckley oaks grow, in the wild, without supplemental water? How many survive? This article provides some insight.
In November and December of 1999, forty-two small wild-growing specimens of Quercus buckleyi were non-randomly selected within juniper/oak forest in Travis County. The heights of the plants were measured. Exclosures were built around each plant to protect it from browsing by white-tailed deer (Odocoileus virginianus). In December of 2003 the heights of the forty-one surviving plants were measured.
The data for the 41 surviving plants are summarized below. Heights are to the nearest centimeter. The heights in 1999 ranged from 2 to 23 cm, with a mean of 7.93 cm and a standard deviation of 4.81. In 2003 the heights ranged from 5 to 29 cm, with a mean of 10.34 cm. The growth over the four years varied from -11 cm (for a plant that died back considerably) to 10 cm. The growth factor (height in 2003 divided by height in 1999) varied from 0.52 to 3.5, with a mean of 1.534.
Summary of the height measurements of the Quercus buckleyi specimens:+--------------+----------+---------+---------+---------+ | Q. buckleyi | minimum | maximum | mean | std dev | +--------------+----------+---------+---------+---------+ | 1999 height: | 2 cm | 23 cm | 7.93 | 4.81 | | 2003 height: | 5 cm | 29 cm | 10.34 | 4.49 | | growth: | -11 cm | 10 cm | 2.41 | 3.08 | | gr factor: | 0.52 | 3.50 | 1.534 | 0.613 | +--------------+----------+---------+---------+---------+
Many of the plants had their tops die sometime during the four years, probably as a result of drought. Such a plant resprouts from the lower, living part of the stem, resulting in a characteristic shape as the new growth eventually curves up and around the remaining dead part. In three cases, the 2003 height was less than the 1999 height. Five had a net growth of zero, and 33 had net positive growth.