Growth Patterns and Biomass Relations of Xanthocephalum sarothrae (Pursh) Shinners on Sandy Soils in Southern New Mexico

Abstract

Growth patterns of broom snakeweed were studied on three areas of sandy range sites in southern New Mexico by measuring plant canopy biweekly during the growing season and calculating canopy volume. Canopy volume increased during the summer of 1977 on all three study areas. In 1978, canopy volume declined throughout much of the growing season because effective rainfall came late in the season. More than 60% of the canopy biomass was contributed by brown stems and leaves, about 30% by green leaves and stems, and less than 10% by inflorescences on most dates. Coefficients of determination relating canopy volume to canopy biomass were less than 0.70. Growth forms and patterns were quite variable among the populations studied.