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.