Using C4 perennial rangeland grasses for bioenergy

Abstract

The aim of this paper was to determine the potential of bioethanol production using two rangeland communities dominated by Spartina argentinensis Parodi or Panicum prionitis Ness. and its environmental sustainability, considering soil organic carbon and biodiversity measured in two taxa: flowering plants and epigeal soil arthropods. S. argentinensis and P. prionitis biomass production with two different harvest frequencies (every 6 or 12 months) was estimated and compared with control areas. Biomass production did not differ with harvest frequency. Although cell wall fibers composition varied with species and treatment, potential bioethanol production per hectare was not affected and yields were similar to those obtained from other lignocellulosic materials reported in the literature. According to our results, one annual harvest is recommended for both plant communities in order to minimize economic and energy costs. Soil organic carbon showed no statistically significant differences due to treatments in the S. argentinensis community, though differences were found in the middle layer (7.5–15 cm) of the P. prionitis rangeland. The vegetation and arthropods biodiversity indices analyzed (richness, evenness, abundance, and diversity) were not affected by treatments.