摘要
通过对重庆石漠化区2种植物群落凋落物层和土壤层的持水性能进行研究,结果表明:马尾松群落的蓄积量高于樟树群落,蓄积量高达48.3 t/hm2,不同分解层次的蓄积量,因植物群落类型不同而有别,测定结果显示针叶林的凋落物的蓄积量、鲜质量、干质量明显高于阔叶林;在两种群落中同种凋落物的不同分解层次的最大持水量、持水率,均是半分解层高于未分解层,马尾松群落持水总量高于樟树群落,达71.5 t/hm2,相应的持水深度也是马尾松群落高于樟树群落;马尾松群落凋落物的吸水量明显高于樟树群落,且每一种凋落物的半分解层的吸水量均大于未分解层,在持水过程中,两种凋落物呈现相同的变化趋势,在前4 h内吸水速率降低幅度大,4 h后吸水速度减缓,20 h后趋向于零.凋落物吸水量和浸水时间之间存在对数关系(y=aln(x)+b),凋落物吸水速率与浸水时间的关系按照反函数方程变化(y=a+bx-1);马尾松群落的总拦蓄量(98.18 t/hm2)大于樟树群落的总拦蓄量(59.26 t/hm2);马尾松群落可截留9.818 mm的林内降雨,樟树群落可以截留5.925 mm的林内降雨.且不同分解层次上也表现为半分解层的有效拦蓄量大于未分解层.表层土壤的持水性能也和凋落物层的持水性能呈现相同的规律,也表现为马尾松林高于樟树林.
The water-holding capacities in 2 main forest types （Pinus tabulaeformis Lamb and Cinnamo mum （L.）Presel） in mountainous eco-system in Karst area of Chongqing were studied. The results showed that the litter storage of P. tabulaeformis （48.3 t/ha） was higher than that of Cinnamomum. Different vegetation types and different decomposition levels resulted in different storages. The litter storage, the wet litter standing crop and the dry litter standing crop of conifers were higher than those of broadleaf for ests. The maximum water-holding percentage and water holding capacity of the semi-decomposed layer was higher than those of the non-decomposed layer of the same vegetation type, and the total water holding ca pacity and the water holding depth of P. tabulaeformis was much higher than that of Cinnamomum. In the water holding process, the litter of the two vegetation types showed a similar trend. Water absorption rate dropped sharply in the first 4 hours, and slightly thereafter and approached zero after 20 hours. The total water holding capacity increased logarithmically with increasing immersion time in water （y = aln（x）＋b）, and water absorption rate in all plantations decreased with increasing immersion time according to the equa tion y = a ＋bx- 1. The total interception amount of P. tabulaeformis and Cinnamomum was 98.18 t/ha and 59.26 t/ha, respectively; and their total interception depth was 9. 818 mm and 5. 925 mm. The modi fied interception amount of the semi-decomposed layer was higher than that of the non-decomposed layer. Like the litter layer, the topsoil showed a similar pattern of the water-holding properties, i.e. the waterholding capacity of the soil of P. tabulaeformis forests was better than that of Cinnamomum forests.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第7期138-144,共7页
Journal of Southwest University(Natural Science Edition)
基金
“十一五”国家科技支撑计划项目(2006BAD03A1006-3)
关键词
重庆石漠化区
凋落物
土壤
水文功能
rocky desertification area of Chongqing
litter
soil
hydrological function
