鼎湖山锥栗木质部形成及其对气候的响应

为了解鼎湖山锥栗(Castaneahenryi)木质部的年内生长动态及其对气候因子的响应,利用微树芯采样技术对锥栗木质部进行连续监测,采用广义可加模型拟合生长过程,并利用混合效应模型分析木质部形成与气候因子的关系。结果表明,鼎湖山锥栗木质部在2015年几乎保持全年生长,呈现显著的季节性差异。在doy200 (200 days of year)之前木质部快速生长(生长季前期),doy300之后(生长季后期)生长速率出现下降趋势。生长季前期的木质部生长速率与温度、光合有效辐射存在显著正相关关系,生长季后期木质部生长速率与气候因子之间的相关关系并不显著。这说明中国南亚热带阔叶树种锥栗木质部形成及其调节机制具有季节性差异,反映了木质部形成对环境的适应性。

Xylem Formation and Response to Climate of Castanea henryi in Dinghushan Mountain

Xylem growth of trees plays an important role in slowing global warming. In order to understand the intra-annual xylem growth dynamics of subtropical Castanea henryi and its response to climate in Dinghushan mountain in south China, the xylem of C. henryi was continuously monitored by microcore sampling technology, the xylem growth in 2015 was fitted by generalized additives models, and the relationship between the xylem growth rate and climate factors was analyzed by using mixed-effect models. The results showed that xylem growth of C. henryi in Dinghushan Mountain kept almost whole year of 2015, and showed significant seasonal differences. The xylem grew rapidly before 200 days of 2015 (early growing season), and showed a down trend in growth rate after 300 days of 2015 (late growing season). The xylem growth rate during early growing season was positively correlated with temperature and photosynthetically active radiation, but that between xylem growth rate and climate factors during late growing season was not significant. So, it was reflected that there were seasonal differences in xylem formation and its regulating mechanism of south subtropical broad-leaved tree C. henryi of China, showing the adaptability of xylem formation to the environment. These could provide data support for deeply understanding and predicting of trees growth in subtropical forest ecosystem under the background of climate change.