Studies on Scavenging Activity Against DPPH Free Radical in Fresh Leaves from Some Common Subtropical Plants of Garden and Afforestion in China Studies on Scavenging Activity Against DPPH Free Radical in Fresh Leaves from Some Common Subtropical Plants of Garden and Afforestion in China THE ACCUMULATION OF UV B ABSORBING COM POUNDS IN LEAVES OF SUBTROPICAL PLANTS Comparison of phenology among tropical plant populations from different source regions