武陵石漠化山地八种针阔叶树种树干液流速率日变化特征

Diurnal variation characteristics of water consumption and sap flow rate of 8 coniferous broadleaved trees in Wuling rocky desertification mountain

以武陵石漠化山地8种针阔叶树种为试验材料,利用TDP树干液流仪监测树干液流速率,研究树干液流速率日变化特征。结果表明:7月不同树种树干液流速率最大值排序为刺楸>木荚红豆>朴树>麻栎>黄樟>马尾松>杉木>柏木。刺楸的树干液流速率最大值出现在11:00,为3893.83 g·cm^(-2)h^(-1);柏木的树干液流速率最大值出现在14:00,为238.00 g·cm^(-2)h^(-1);阔叶树种的树干液流速率均大于针叶树种的。9月不同树种树干液流速率最大值排序为麻栎>木荚红豆>黄樟>马尾松>刺楸>朴树>柏木>杉木。麻栎的树干液流速率最大值出现在9:00,为3314.31 g·cm^(-2)h^(-1);杉木的树干液流速率最大值出现在11:00,为314.18 g·cm^(-2)h^(-1)。7月不同树种日平均树干液流通量排序为刺楸>木荚红豆>马尾松>黄樟>麻栎>朴树>杉木>柏木,刺楸的最大树干液流通量是柏木的16.36倍;9月不同树种日平均树干液流通量排序为麻栎>木荚红豆>马尾松>刺楸>黄樟>朴树>柏木>杉木,麻栎的最大树干液流通量是柏木的11.71倍。除麻栎、木荚红豆外,其它树种平均日耗水量都是7月的大于9月的。不同树种对不同的环境因子响应不同,其中太阳总辐射及土壤温度与树干液流速率相关性最强,影响树种蒸腾速率的气候因子主要是太阳总辐射。

In this study,eight coniferous and broad-leaved tree species in Wuling rocky desertification mountain were used as experimental materials.The trunk sap flow rate was monitored by TDP trunk sap flow instrument,and the diurnal variation characteristics of stem sap flow rate were studied.The results showed that the order of the maximum sap flow rate of different tree species in July were as follows:Kalopanax septemlobus>Ormosia xylocarpa>Celtis sinensis>Quercus acutissima>Cinnamomum porrectum>Pinus massoniana>Cunninghamia lanceolata>Cupressus funebris.The maximum flow rate of Kalopanax septemlobus was 3893.83 g·cm^(-2)h^(-1) at 11:00,and that of C.funebris was 238.00 g·cm^(-2)h^(-1) at 14:00.The sap flow rate of hardwood trees was higher than that of coniferous.The order of the maximum sap flow rate of different tree species in September was as follow:Q.acutissima>O.xylocarpa>C.porrectum>P.massoniana>K.septemlobus>C.sinensis>C.funebris>C.lanceolata.The maximum sap flow rate of Q.acutissima was 3314.31 g·cm^(-2)h^(-1) at 9:00,and the maximum sap flow rate of C.lanceolata was 314.18 g·cm^(-2)h^(-1)8 at 11:00.In July,the order of dairy average sap flow of different tree species was K.septemlobus>O.xylocarpa>P.massoniana>C.porrectum>Q.acutissima>C.sinensis>C.lanceolata>C.funebris.The maximum average flow rate of K.septemlobus was 16.36-time higher than that of C.funebris.In September,the average daily liquid flow of different tree species ranked as Q.acutissima>O.xylocarpa>P.massoniana>K.septemlobus>C.porrectum>C.sinensis>C.funebris>C.lanceolata.The maximum average flow rate of Q.acutissima was 11.71-times higher than that of C.lanceolata.The average daily water consumption of other tree species was greater in July than in September,except for Q.acutissima and O.xylocarpa.Different tree species have different responses to different environmental factors,The total solar radiation and soil temperature have the significant correlation with the sap flow rate of the tree trunk.The climatic factors affecting the transpiration rate of tree species were mainly the total solar radiation.