ON THE METHOD OF LINE TAXATION FOR DETERMINING AMOUNTS OF BARK STRIPPING

Between 1995 - 1997 the method of line taxation was used to survey 124 samples of bark stripping damage incurred in the red deer districts o f North and Ruhreifel, Northrhine Westfalia (Tab.3). On the basis of 1 50000 counted trunks this investigation showed an optimal method for t he determination of bark stripping. Of paramount importance here is a sufficiently large sample size of trunks in bark stripping prone stand s (Tab.1). The inclusion of 1000 trunks in 10 100 trunk rows per sampl e plot suffices (Fig.1) The average sampling time including driving ti me from stand to stand and brief preparation time before and after sam pling is about 3 hours, maximally 4 hours for one person. In order to determine the amount of bark stripping as completely as possible, beec h stands were sampled in August and spruce in mid-September The data w ere statistically tested using a binomial distribution to provide suff icient accuracy in the determination of percent stripping (Tabs. 4 and 5). In comparing the present various methods for the determination of bark stripping damage to line taxation, this method has the clear adv antage of a high degree of precision in determining percent bark strip ping and large sample size in comparison to spot sampling. In addition the time consuming search for the individual sample plots in the sele cted sample areas can be circumvented.