A Statistical Method for the Accurate and Rapid Sampling of Urban Street Tree Populations

Abstract

This paper develops and demonstrates a statistical sampling method that can be used to estimate the species composition of an urban street tree population quickly and accurately, i.e., with an acceptable level of error. The technique is based on stratified random sampling. We first estimate the percentage of street trees in separate zone segments throughout the city, and then distribute a sample of 2,000-2,300 trees across the city. Weighted averaging is used to obtain estimates and confidence limits. We have applied this technique in four cities in New York state and obtained results that agree closely with previously existing complete or partially complete street tree surveys.