冰雪灾害后粤北杉木林冠残体和凋落物的持水特性

Water Capacity Characteristic of the Broken Crown and Litter in a Cunninghamia lanceolata Stand Suffered from Ice-Snow Damage in North Guangdong Province

对冰雪灾害后杉木林的林冠残体和凋落物的储量、持水量、持水率和吸水速率进行研究。结果表明:杉木林冠残体的干、枝、叶和皮的干质量分别为11.42,7.03,5.76和1.78t·hm-2,凋落物干质量为5.93t·hm-2;各组分的最大持水量表现为干(11.83t·hm-2)>叶(11.24t·hm-2)>凋落物(10.88t·hm-2)>枝(6.73t·hm-2)>皮(2.38t·hm-2);各组分中叶的最大持水率居首位,达295%,凋落物为272%,皮为234%,枝和干分别为196%和193%;浸泡时间在0.5～6h之间,各组分的吸水速率随浸泡时间的增长急剧下降,此后缓慢下降;各组分的持水量和持水率随着浸泡时间的增加按照自然对数方程增加,各组分的吸水速率随浸泡时间的增长按负指数方程下降。

The dry mass,water holding capacity,proportional water holding capacity of crown debris and litter were measured in a Cunninghamia lanceolata stand suffered from ice damage.The dry mass of stems,branches,leaves,bark of the broken crown and litter were 11.42,7.03,5.76,1.78,5.93 t·hm^-2,respectively.The order of maximum water holding capacity of the components was stem（11.83 t·hm^-2）〉 leaves（11.24 t·hm^-2）〉litter（10.88 t·hm^-2）〉 branches（6.73 t·hm^-2）〉 bark（2.38 t·hm^-2）.The proportional water holding capacity as a percentage of dry mass in the components were 295%,272%,234%,196% and 193% for leaves,litter,bark,branches and stem,respectively.Water absorption rate of the components quickly decreased with increasing immersed time from the initial 0^5 to 6 hours and then decreased slowly.The total water holding capacity and proportional water holding capacity of thecomponents increased logarithmically with increasing time immersed in water,whereas water absorption rates of components decreased according to negative exponential equation with increasing time immersed in water.