Abstract: Different impacts of human activities including tourism, religious activity and industrial activities on atmospheric CO2, NOx and SO2 concentration of the subtropical forests and the chlorophyll fluorescence of two woody plant species ( Schima superba Gardn. et Champ. and Pinus massoniaha Lamb. ) were studied. The experimental sites were at Dinghushan Biosphere Reserve and its nearby industrial area in Guangdong Province. In recent years, the Biosphere Reserve has received more than 700 000 tourists and nearly 120 000 vehicles each year. A steel production plant and a chemical plant are located in the nearby industrial area. The chlorophyll fluorescence was measured by a modulation pulse fluorometer (PAM). The results showed that the effects of human being activities have caused an increase of the concentration of CO2, NOx and SO2 within the forests. Comparing to the control site (core area of Biosphere Reserve), the CO2, NOx and SO2 concentration in the disturbed sites have increased 17 to 40 μmol· mol-1, 5 to 20 nmol· mo1-1 and 2 to 19 nmol·mol-1 respectively. The Fv/Fm, qp and ФPSⅡof two woody plants decreased with the increase of human being activities. The trend of decreasing Fv/Fm, qp and ФPSⅡ associated with an increase of qN in leaves of forests plant was consistent with the increasing CO2, NOx and SO2 concentration within the forests.

Key words: Human activities, CO2, NOx, SO2, Chlorophyll fluorescence