Quantifying Species Diversity of Streetside Trees in our Cities

Abstract

Biological/genetic diversity is a key factor in the stability and disease tolerance of streetside tree populations. Low species diversity may leave the tree population more vulnerable to new stress environments, both abiotic and biotic. Monitoring and enriching the species diversity level has become an important issue in streetside tree planning and management. The present study introduces an index to species diversity in streetside tree populations (SDI). SDI allows quantitative comparisons of species diversity between tree populations. SDIs of 21 cities and towns are calculated based on literature published in the past 10 years. The diversity levels of streetside trees in our cities may have to be doubled to avoid species-specific catastrophic losses.