| Since the 20th century, the effect of global climate change on ecological system had been more profound. Much research indicated that different response of plant to climate factor would influence the structure and composition of community and then lead the variation of vegetation pattern. Thus, study on radial growth dynamic of different plant and its' relationship with climate factors using dendroecological method will be in favor of quantitating the effect of climate change on the structure and composition of plant community. Pinus koraiensis, Populus davidiana and Picea jezoensis var. komarovii were selected in this paper as a typical species, pioneer tree in a zonal vegetation, broad-leaved Korean pine forest and a typical species in dark forest respectively. Tree-ring chronologies were developed at six altitudes:600 m (lower altitudinal border of Korean pine forest, later referred to as site DX and XF),800 m (middle altitudinal of Korean pine forest, site GM and DZ),1000 m (middle altitudinal of Korean pine forest, site CBM1),1200 m (high altitudinal border of Korean pine forest and lower altitudinal border of dard forest, site CBM2),1400m (ecological boundary of Pinus koraiensis and middle altitudinal border of Picea jezoensis var. komarovii, site CBM3), and 1600 m (high altitudinal border of Picea jezoensis var. komarovii, site CBM4). Radial growth dynamics of Pinus koraiensis, Populus davidiana and Picea jezoensis var. komarovii, and their relation with climate factors were analyzed from four aspects, elevation, fire disturbance species characteristics, and the gender. Climatic variables were monthly mean, maximum and minimum temperature and monthly total precipitation over the period from previous year May through current year September. We also try to establish the growth model in nature condition to discuss the effect of climate change on typical trees'growth. The main conclusions were as follows:(1) The distributions of diameter at breast height (dbh) of Pinus koraiensis were different along the gradient of elevation. The dbh size increased with the elevation. There was a poor relationship between the dbh and age for Pinus koraiensis. The dbh of Picea jezoensis var. komarovii decreased with the elevation. The relation between the dbh and age was different from each site. There were positive relations between the dbh and age of Picea jezoensis var. komarovii and Populous davidiana (p<0.05). Tendency of Pinus koraiensis's increment varied among different sites. The increments of Picea jezoensis var. komarovii were accord with each site. Under the same environment condition, interannual variation of increment was different among three typical species, with the sharpest one was Pinus koraiensis, then Populus davidiana and the slowest one was Picea jezoensis var. komarovii. Through time series analysis of principle component of different species, we also found the interannual variations were influenced by common signals (climate, environmental condition and species characteristics). Though the impact was different, it concentrated on the period of 1971-1976,1982-1994 and 1999-2006. Therefore, it was necessary to analyze the relationship between the typical species and climate factors systemly.(2) Along the altitudinal gradient, the relation between the trees'growth of Pinus koraiensis and climate factors was differential, but no difference happened for Picea jezoensis var. komarovii. At low altitude, Pinus koraiensis was positively controlled by precipitation, especially the precipitation in current July. Along the increasing of altitude, the importance of temperature increased and the correlation with precipitation changed. At middle altitude, Pinus koraiensis were positively driven by the mean and maximum temperature in current April. In other hand, the radial growth of Pinus koraiensis in GM site was negative related with the precipitation in previous August, but it turned into positive in CBM1 site. At high altitude, the radial growth of Pinus koraiensis were mainly positively influenced by growing season temperature, mean and minimum temperature in current July, mean temperature in current August. Different from above results, the analysis of climate characteristics in extreme years show that at low altitude, trees were strongly correlated with spring precipitation. Radial growth of Picea jezoensis van komarovii were in accord among different elevation, which negatively related with temperature in previous July and precipitation in current May, but positively significantly related with mean and minimum temperature in current May. Spring temperature had strong and positive impact on its growth in extreme year.(3) Fire disturbance improve the trees'growth of Pinus koraiensis and make it to be more sensitive with climate change. At the early year of fire occurred and the period between the year of 1949 and 1981, the increment of fire-damaged Pinus koraiensis was significantly higher than the undamaged one. The radial growths of fire-damaged trees were driven by the growing season temperature and precipitation in previous growing season. Oppositely, the undamaged trees were mainly influenced by previous growing season temperature and current growing season precipitation. In addition, the fire-damaged trees were also significantly related with the neighbor competition under the assumption that the spatial pattern didn't changed in the lasted five years.(4) Different response of differential species to climate factors occurred in the same environmental condition. It also added evidence that growth-climate relationship was species-characteristic. In broad-leaved Koran pine forest, the radial growth of Pinus koraiensis was positively controlled by minimum temperature in previous November and current April, and precipitation in current July, but negatively related with the precipitation in previous July and August. Whereas, Populus davidiana was significantly negative with mean temperature in current January, and precipitation in previous June and current September. In the transition zone of broad-leaved Korean pine forest and dark forest, the radial growth of Pinus koraiensis was significantly and positively related with mean temperature in current July, but Picea jezoensis var. komarovii was significantly positive with the mean temperature in current May, but negative with the precipitation in this month. (5) Growth of the males of Populus davidiana was significantly higher than that of the females in the lasted 5 and 10 years. The females and males were significantly negative with the precipitation at the end of current growing season (current September). The females showed more sensitive with the climate change. The females were mainly negatively controlled by temperature in previous winter (previous October and current February) and spring precipitation (current March). The males were significantly positive with the spring temperature (current March).(6) Except for Picea jezoensis var. komarovii, the relationship between the radial growth of Pinus koraiensis and Populus davidiana, and weather variables could be simulated, especially for fire-damaged Pinus koraiensis. Combining the climate variation pattern in Changbai Mountain with temperature increasing and precipitation decreasing, growth of Pinus koraiensis growing at low altitude and disturbed by fire would be inhibited. Growth of Pinus koraiensis at middle and high altitude would be benefit from the climate change. The growth of females of Populus davidiana would be decreased, but that of the males would be improved. |
