黔中不同龄组柳杉人工林枯落物水源涵养能力综合评价

Water Conservation Ability of Litter in Cryptomeria fortunei Plantation with Different Age Groups in Central Guizhou

为了解不同林龄柳杉人工林枯落物的水源涵养能力,为森林水土保持措施的确定和实施提供依据,于2018年10月选取平坝区大坡林场5个龄组柳杉人工林作为研究对象,采用烘干法和实验室浸水法对枯落物的持水性能进行研究,并采用熵权法对柳杉人工林5个龄组枯落物水源涵养能力进行综合评价。结果表明:(1)随着柳杉人工林的生长发育,枯落物储量及持水特性呈现先增加后减小的趋势,表现出成熟林最大,幼龄林最小。其中成熟林枯落物厚度为7.40cm,蓄积量为2.21t/hm^2,最大持水量为6.46t/hm^2,最大持水率为265.14t/hm^2,有效拦蓄量为3.94t/hm^2,有效拦蓄率为175.74%。(2)利用熵权法计算出柳杉人工林5个龄组枯落物的水源涵养能力为成熟林(11.46)>近熟林(10.79)>过熟林(8.26)>中龄林(4.83)>幼龄林(3.94),柳杉成熟林具有最佳的水源涵养能力。

The purposes of this study were to understand the water conservation capacity of litter of Cryptomeria fortunei plantation with different forest ages,and to provide basis for the determination and implementation of forest soil and water conservation measures.Five age groups of C.fortunei plantation in Pingba Dapo Forest Farm of Guizhou Province were chosen as object in October 2018.The water holding capacity of litter was studied by drying method and laboratory immersion method,and the water conservation function of litter in five age groups was evaluated comprehensively by entropy weight method.The results showed that:(1)With the growth and development of C.fortune plantation,litter reserves and water holding characteristics showed a trend of first increasing and then decreasing,showing that mature forest was the largest and young forest was the smallest.The litter thickness,volume,maximum water-holding capacity,maximum water-holding rate,effective storage capacity and effective storage rate of mature forest were 7.40 cm,2.21 t/hm^2,6.46 t/hm^2,265.14 t/hm^2,3.94 t/hm^2,and 175.74%respectively.(2)The water conservation capacity of litter in five age groups was calculated by the method of entropy weight,which was:mature forest(11.46)>near-mature forest(10.79)>over-mature forest(8.26)>middle-aged forest(4.83)>young forest(3.94).The mature forest had the largest water conservation capacity.