Herbicide Conversion of a Sand Shinnery Oak (Quercus Havardii) Community: Effects on Biomass

Abstract

Seasonal biomass dynamics were documented in an undisturbed sand shinnery oak (Quercus havardii) community and adjacent areas treated with tebuthiuron 3 years and 6 years prior to sampling. Biomass was measured for above-ground and below-ground compartments during growth initiation, peak standing crop, and winter dormancy in 1981. Total biomass showed little change on plots treated 3 years prior to sampling compared to the untreated oak plot. However, there was a decrease in total biomass on the 6-year plot compared to the other 2 treatments. Above-ground biomass decreased on both treated sites compared to the untreated plot reflecting oak death and decomposition.. Above-ground herbaceous material increased approximately 6-fold on both treated sites compared to the untreated plot. Oak root biomass decreased 12% at 3 years and 37% at 6 years following treatment. Herbaceous root biomass increased 3-fold on the 3-year-old treatment compared to the untreated oak community and was twice as much on the 6-year-old treatment compared to the untreated site. Distribution of herbaceous roots by soil depth was altered by treatment with a higher percentage of roots on the surface 30 cm on the treated sites compared to the untreated sites.