Variations in the carbohydrate components of introduced grass species between sunny and shady slopes at Cooper Creek: A report submitted in partial fulfilment of the requirements for the Degree of Bachelor of Science (Hons.) in the University of Canterbury

Abstract

The carbohydrate analyses of the grass species: ryegrass, browntop, cocksfoot and the resident pasture at Cooper's Creek were carried out. The samples were collected from sunny and shady areas at Cooper's Creek, and the carbohydrate contents extracted and fractionated according to Bailey's scheme (Figure 1). The individual carbohydrate components were analysed, the anthrone method being used for total soluble sugars, Dische's method for pectin, and Nelson's method for cellulose and hemicellulose. The amount of lignin present was also evaluated by reducing the residue to ash in an oven at 600°C. The total carbohydrate content was found to be higher on the shady slopes than the sunny slopes. When the individual components were examined, the total soluble sugars, hemicellulose and cellulose percentages were found to be higher on the shady slopes while that or pectin was lower. The value of lignin did not seem to be affected though in most cases its value was lower on the shady side. The individual components were also sensitive to seasonal changes. The main pattern of change is an increase in summer and a decrease towards autumn. The only exception is cocksfoot which showed the reverse response.