Field investigation: spatial variations in leaf trichomes and their relationships with environmental factors
We collected 44 populations in situ across the whole of Eastern Asia from 2007 to 2009, including mainland China, Peninsular Korea, Japan, the Zhoushan Islands and Taiwan Island. At each population, five dominant trees were selected, after which 20 healthy and mature leaves per tree were collected from three twigs in the upper central south-facing crown. Leaf samples were collected from between 9:00 am to 12:00 noon every day from August to September. The sampled leaves were divided into two sections for the measurement of trichome and stomatal densities and other leaf functional traits.