三种阔叶林凋落物的持水特性

对火力楠、荷木和黎蒴的凋落物的储量、持水量、持水率和吸水速率进行了研究。结果表明,火力楠、荷木和黎蒴林地的凋落物干重分别为10488,5159,5583kg／hm^2。浸泡2h前凋落物持水量呈现火力楠林地〉黎蒴林地〉荷木林地,浸泡2h后为黎蒴林地〉火力楠林地〉荷木林地。3种林分中黎蒴林地的凋落物最大持水量在居首位,达17709kg／hm^2,火力楠林地居中,为16576kg／hm^2,荷木林地较小,为13374kg／hm^2。不同浸泡时间段的凋落物持水率均呈现黎蒴林地〉荷木林地〉火力楠林地。火力楠、荷木和黎蒴林地的凋落物最大持水率分别为158％,258％和309％。凋落物持水量和凋落物持水率随着浸泡时间的增加按照对数关系增加。凋落物吸水速率呈现黎蒴林地〉荷木林地〉火力楠林地。各林分的凋落物的吸水速率随浸泡时间的增长按反曲线关系下降。

Water Holding Characteristics in Three Broadleaved Plantations

The characteristics,such as standing crop,water holding capacity,and proportional water holding capacity and absorption rates,were studied in plantations of Michelia macclurei,Schima superba and Castanopsis fissa.The dry litter standing crop of M.macclurei,S.superba and C.fissa were 10 488,5 159 and 5 583 kg/hm~2,respectively.The order of total water holding capacity of litter was M.macclurei>C.fissa>S.superba before 2 h immersed in water and was C.fissa>M.macclurei>S.superba after 2 h immersed in water.The biggest water holding capacity of litter of C.fissa woodland was the largest(17 709 kg/hm~2) among the three woodlands,followed by the M.macclurei woodland(16 576 kg/hm~2) and the S.superba woodland(13 374 kg/hm~2).The proportional water holding capacity as a percentage of the litter dry weight in M.macclurei,S.superba and C.fissa woodlands were 158%,258% and 309%,respectively.The total water holding capacity and proportional water holding capacity of litter increased logarithmically with increasing time immersed in water.The order of water absorption rate of litter in the three woodlands was C.fissa>S.superba>M.macclurei.Water absorption rates of litter in all plantations decreased according to equation Y=a b/t with increasing time immersed in water.