枫杨种源苗期生长节律及生物量预测

于枫杨全分布区内收集的５５个种源为试材进行苗期试验。在北亚热带地区，枫杨的高生长季节约为８个月，即３月至８月底。７月为其生长高峰，净生长量占整个生长季生长量的３７．７２％，６月与８月、５月与９月的净高生长量相差无几，分别占２２％－２５％以及８％－１０％，民苗高净生长节律主要受气温因子的影响，而与雨量关系不大。枫杨高生长种源间差异表现在７－９月，５个生长最快与５个生长最慢种源组间的月均相差在１５cm以上。７月可以作为速生种源苗期初步选择的时期，以各月苗高净生长量、年度苗高与地径生长量分别构建２ 生物量预测模型，２组模型均具有较好的预测潜力，其中以各月苗高净生长量为自变量的模型具有更高的预测精度，且能提前３个月左右建模。

Studies On Growth Rhythem And Biomass Estimation of Pterocarya stenoptere Seedling from Diffrent Provenances

The 55 Pterocarya stenoptere provenances collected from its whole distribution were tested .Its growth period lasts about 8 months ranging from March to October. Its growth peak appears in July and the net increment amounts to 37.72% of the whole season. Meanwhile, the height increment of May and June are accordingly simillar to September and August, respectively, they are 22%-25% and 8%-10%.The height growth is mainly influnced by local temperature factors rather than rainfall. The growth differences .between different provenances occur between July and September, the differences between five of the best growing provenances and five of the worst are more than 15cm.July is the reasonable time for choosing fast growthing provenance. The two models of biomass estimation, constructed on the basis of monthly net height increment, total height and diameter, have hotter estimating ability, but the model based on monthly net height increment have better accuracy, which can be constracted 3 months in advance..