自然干旱后不同系号杨树湿心材的特征

Wet Heartwood Characteristics of Different Poplar Clones After Natural Drought

以2017年造林材料为对象,比较不同系号杨树湿心材在大旱前和大旱后的变化差异。结果表明:干旱前和干旱后所有系号杨树的湿心材长度比例均呈显著正态分布。所有系号均存在湿心材现象,且整体上湿心材比较严重。杨树径生长由于干旱受到了严重抑制,但随着直径的增加及干旱的影响,湿心材长度比例继续增大,木芯含水率略有下降,干旱会减轻湿心材的危害。不同材料湿心材的pH差异不显著,均为弱碱性,江汉平原主栽的4个品种插干造林生长速度有一定优势,但湿心材相比带根造林更为严重一些。对连续2 a的湿心材特征进行相关分析,发现湿心材主要特征之间存在极显著正相关。

Taking the afforestation materials in 2017 as the object,this study compared the differences in wet heartwood characteristics of different clone poplar trees before and after severe drought.The results showed that the length proportion of wet heartwood in all clone poplar trees exhibited a significant normal distribution before and after drought.Wet heartwood was observed in all clones,indicating a severe wet heartwood phenomenon overall.The diameter growth of poplar trees was severely inhibited by the drought,but as the diameter increased and the drought intensified,the length ratio of wet heartwood continued to increase while the moisture content in the wood core slightly decreased,suggesting that drought could alleviate the harm of wet heartwood.The pH difference of wet heartwood among different materials was not significant,with all being weakly alkaline.Among the four main varieties planted in the Jianghan Plain,the growth rate of the cutting afforestation had a certain advantage over root planting,but wet heartwood was more severe than that of the root-planted afforestation.Correlation analysis of wet heartwood characteristics for two consecutive years showed a significant positive correlation between the main wet heartwood characteristics.