甘肃兴隆山青杄林树干径向生长及其对气象因子的响应

Radial Growth and Response to Meteorological Factors of Picea wilsonii in the Xinglong Mountain of Gansu Province

以甘肃兴隆山国家级自然保护区林区顶级群落青杄为研究对象,利用甘肃兴隆山森林生态系统国家定位观测研究站2018-2020年度气象和不同径阶树木径向生长的数据,探究该区顶级群落青杄树干径向生长规律。结果表明,青杄树干径向生长与大气温湿度和热通量显著正相关,与土壤含水量和光合有效辐射呈负相关,与土壤温度不相关;青杄4-6月为快速生长期,7-10月进入缓慢生长期,11月至次年3月缓慢收缩;7:00-12:00为青杄树干收缩阶段,12:00-16:00,为膨胀阶段,16:00之后半径逐渐增加,在4:00达到最大值并持续至7:00,随后进入下一轮周期;降水条件下,不同胸径青杄较晴朗天气均表现出长周期,收缩期(SP)持续时间显著减少,膨胀恢复期(RP)时段加长,甚至表现出生长期(IP)周期持续的现象;青杄的生长受到上一年生长季末温度和降水的显著影响,这种影响主要是由树木体内养分积累状况造成的。

Taking the top community Picea wilsonii occurring in Xinglong Mountain National Nature Reserve of Gansu Province as the study object,the variation law of the tree ring was researched by using the meteorological and radial growth data collected during 2018-2020 in Xinglongshan Forest Ecosystem Positioning Research Station.The results showed that the radial growth of P.wilsonii was positively correlated with air temperature,humidity and heat flux,negatively correlated with soil water content and photosynthetically active radiation,but not correlated with soil temperature.P.wilsonii was in the fast growing period from April to June,entering the slow growing period from July to October,and contracting slowly from November to March.The stem of P.wilsonii was in contraction stage from 7:00-12:00 and in expansion stage from 12:00-16:00,in max at 16:00-4:00,and then moved on the next cycle.P.wilsonii with different diameter at breast height(DBH)all appeared long period in rainy weather,it would lead to a significant reduction in SP and cause a longer RP,and even persistent IP.The accumulation of nutrients of the trees were affected by the temperature and precipitation at the end of the last growing season,and thus the growth in the next growing season was affected.