防火林带不同树种枝叶持水率研究

Study on leaves and branches moisture of eight different tree species for fire-prevention forest belts in Xuyi county,China

通过对盱眙香樟、女贞、侧柏、广玉兰、杨树、海桐、油茶和淡竹等8种树种的鲜枝叶含水率和枯枝叶最大持水率的测定,分析了不同木质可燃物的失水率。结果表明:(1)杨树的鲜叶含水率、鲜枝含水率、枯叶最大持水率和枯枝最大持水率等4种含水率都明显大于其他树种,女贞、广玉兰、海桐、油茶等4种植物的4种含水率也相对较高;侧柏和淡竹除了枯叶最大持水率稍高外,其他3种含水率较低,香樟枯枝最大持水率较低,其他3种含水率中等。(2)广玉兰和杨树的鲜叶和鲜枝失水速率都是最慢的,而侧柏和油茶较快,其他树种为中等失水速率;枯枝叶失水都较慢的有杨树、广玉兰和女贞,其次为香樟、侧柏,其他树种有的枯叶失水快,有的枯枝失水快。

The moisture of fresh leaves and branches and the maximum water-holding rate of withered leaves and branches at 8 tree species in Xuyi county were determined in laboratory,and different fuel moisture loss were analyzed.The results showed that the moisture of fresh leaves,fresh branches,leaf litter and branch litter in Populus tomentosa was the highest among the 8 tree species.Ligustrum lucidum,Magnolia grandiflora Linn.,Pittosporum tobira and Camellia oleifera Abel.were in the second.The maximum water-holding rate of leaf litter in Platycladus orientalis and Phyllostachys glauca McClure was higher than those in the other 6 tree species.However,the maximum water-holding rate in fresh leaves,fresh branches and branch litter were lower than those of the others.The maximum water-holding rate of withered branches in Cinnamomum camphora Presl.was significant lower,and of fresh leaves,fresh branches and leaf liter were in medium.On the other hand,fresh leaves and branches moisture loss in M.grandiflora Linn.and P.tomentosa was the slowest,while P.orientalis and C.oleifera Abel were the fastest.Withered leaves which had slow moisture loss were P.tomentosa,M.grandiflora linn and L.lucidum,but C.camphora Presl.loss moisture faster than other tree species for withered leaves.