喀斯特灌木林枯落物持水特性分析

灌木是喀斯特地区的主要植被类型之一,研究其枯落物的持水特性对喀斯特地区水源涵养和生态修复具有重要意义。为了解不同灌木群落和坡位的枯落物持水能力,采用室内浸泡法和烘干法,分析了3种灌木群落和处于3种不同坡位的混合灌木林枯落物的持水能力。结果表明:3种灌木群落枯落物的总蓄积量表现为球核荚蒾圆果化香月月青,3种坡位群落枯落物的总蓄积量表现为坡下坡中坡上;无论群落或是坡位,枯落物蓄积量均表现为半分解层大于未分解层;群落最大持水量为圆果化香月月青球核荚蒾,不同坡位最大持水量为坡中坡下坡上;圆果化香的持水能力较强,坡中的持水能力较好;不同群落和不同坡位的枯落物持水量与浸泡时间都存在对数关系,吸水速率与浸泡时间存在幂函数关系。

Water holding characteristics of litter in karst shrubs

Shrub is one of the main vegetation types in the karst area. It is of great significance to study the water holding characteristics of litter in karst area for water conservation and ecological restoration. Using indoor immersion and drying methods, this study aimed to investigate the water-holding properties of the three types of shrub communities and mixed shrubs at three different slope positions in the karst region. The results showed that the total litter accumulation in the three shrub communities was characterized by Viburnum propinquum Hemsl>Platycarya longipes Wu>Itea ilicifolia Oliv, the total litter accumulation of in the three slopes position was expressed as bottom>middle>top of the slope. Regardless of the different species or slopes, the litter accumulation of the semi-decomposed layer was greater than the undecomposed layer. The maximum hydroscopic water amount was Platycarya longipes Wu>Itea ilicifolia Oliv>Viburnum propinquum Hemsl. The maximum hydroscopic water amount was middle>bottom>top of the slope. Through the comparative analysis of different shrub communities and slope positions, it was concluded that the water holding capacity was the greatest for forest litter of Platycarya longipes Wu and at the middle slope position the water holding capacity was great. There was a logarithmic relationship between the amount of hydroscopic water and immersion time of the litter in different communities and different slope positions. A power function best described the relationship between water absorption rate and immersion time.