//---------------------------------------------------------------------
        /// <summary>
        /// Computes last browse prop for a cohort
        /// </summary>
        /// <returns>
        /// </returns>
        public double UpdateLastBrowseProp(IDisturbance disturbance)
        {
            //  Go backwards through list of cohort data, so the removal of an
            //  item doesn't mess up the loop.
            double totalBrowseProp = 0;

            for (int i = cohortData.Count - 1; i >= 0; i--)
            {
                Cohort cohort         = new Cohort(species, cohortData[i]);
                double lastBrowseProp = disturbance.ChangeLastBrowseProp(cohort);
                cohort.ChangeLastBrowseProp(lastBrowseProp);
                cohortData[i]    = cohort.Data;
                totalBrowseProp += lastBrowseProp;
            }
            return(totalBrowseProp);
        }