MESQUITE SAVANNA PROJECT

One objective of our research is to investigate the the integrated use of prescribed fire and herbicides to manipulate the growth form and density of honey mesquite and convert mesquite woodland thickets to savannas.

Low-intensity fires can be utilized to manipulate the growth form of mesquite by reducing foliage in lower portions of the mesquite canopy while preserving apical dominance and limiting basal regrowth that occurs following a top-killing treatment.  This illustration shows a low-intensity winter fire moving through a mesquite stand.  Increments on the measuring poles are 1 meter. 

The image at right shows a mesquite stand that has been partially top-killed by low-intensity fires.  Apical dominance is maintained, basal sprouting is suppressed and the reduced canopy foliage has stimulated grass growth.  Low rates of clopyralid herbicide (0.25 to 0.38 lbs/ac) can produce a similar effect.  

The net result is that mesquite has less foliage per tree and is less competitive with grasses, yet it does not produce resprouts that will eventually become multi-stemmed thickets.  The remaining foliage also provides cover for wildlife.  The chart at left shows how low-intensity fires and low rates of clopyralid followed by low intensity fires can be used to manipulate the growth form of mesquite.  Some   summary articles are available here:

Ansley 1996 Cattleman magazine (color)

Ansley 1996 Cattleman magazine (greytone)

Ansley 1999 Field Day Proceedings (color)

Ansley 1999 Field Day Proceedings (b&w)

But check out other publications on the links above.