摘要
以毛乌素沙地东南缘榆林市城北6 km的珍稀沙生植物保护基地为研究地点,通过对30个相同立地条件下10种不同造林密度（即10种森林类型,每种设3个重复）的樟子松（Pinus sylvesiris var.mongolica）人工林标准地进行调查、林下枯落物和土壤持水能力的定量测定,比较并分析了造林密度对其林下枯落物和土壤持水性能的影响。这10种樟子松样地的编号及造林密度分别为PⅠ（900 plant·hm^-2）、PⅡ（1 200 plant·hm^-2）、PⅢ（1 500 plant·hm^-2）、PⅣ（1 800 plant·hm^-2）、PⅤ（2 200plant·hm^-2）、PⅥ（2 500 plant·hm^-2）、PⅦ（2 800 plant·hm^-2）、PⅧ（3 000 plant·hm^-2）、PⅨ（3 300 plant·hm^-2）和PⅩ（3 600 plant·hm^-2。结果表明,（1）各样地枯落物总量（TL）的排序依次为TLPⅢ=TLPⅣ〉TLPⅩ〉TLPⅧ〉TLPⅨ〉TLPⅥ〉TLPⅦ〉TLPⅤ〉TLPⅡ〉TLPⅠ;最大持水量的变动范围为2.46~8.23 t·hm^-2;有效持水量在0.163~6.42 t·hm^-2,PⅢ和PⅣ样地枯落物持水功能表现最好,PⅠ样地表现最差。（2）各林地林下土壤自然含水量、土壤容重和土壤最大持水量无显著差别,变动范围分别在8.94%~16.54%、1.10~1.66g·cm^-3和200.43~266.43 t·hm^-2;土壤非毛管孔隙度差异较大,变动范围为0.99%~4.32%;PⅢ和PⅣ样地土壤持水功能表现最好,PⅠ样地表现最差。（3）利用幂函数分别对枯落物吸水速度与浸泡时间、枯落物持水量与浸水时间进行拟合,均有较高的拟合系数。各样地森林土壤的平均稳渗速率几乎没有差异,均在20 min左右稳定在0.11~0.89 mm·min^-1。（4）研究发现,PⅢ和PⅣ样地枯落物和土壤持水能力最好,最佳造林密度是1 500~1 800 plant·hm^-2。为防止林分衰退,应及时适当间伐。同时,该地区是否适合大面积大密度的樟子松人工造林,还有待进一步研究。
A case study was conducted at the Rare Sand Plant Protection Base, about 6 km north from Yulin city, which lies in north of Shaanxi province and the southern edge of Mu Us Sandland, China. For the purpose of comparing and analyzing the effects of 10 different density plantations ofPinus sylvesirisvar. mongolica on the water-holding capacity of forest litter and soil, 30 standard plots of artificial forest with the same site conditions （10 types of forest＆#215;3 replications） were investigated and the water-holding capacity of litter and soil were determined quantitatively. The ten types of sample plots were recorded asPⅠ,PⅡ,PⅢ,PⅣ,PⅤ,PⅥ,PⅦ, PⅧ,PⅨ, andPⅩ, and the afforestation densities of Pinus sylvesirisvar. mongolicawere 900, 1200, 1500, 1800, 2200, 2500, 2800, 3000, 3300 and 3600 plant·hm^-2 respectively. The results showed that, （1） The total capacity of litter （TL） among 10 forest types, generally followed by the sequence of forest densities, were TLPⅢ=TLPⅣ〉TLPⅩ〉TLPⅧ〉TLPⅨ〉TLPⅥ〉TLPⅦ〉TLPⅤ〉TLPⅡ〉TLPⅠ; the maximum water-holding capacity and effective water-holding capacity of litter, for 10 forest types, were 2.46~8.23 t·hm^-2 and 0.163~6.420 t·hm^-2 respectively. The water-holding functions of litter inPⅢ and PⅣ plotswere the best and was the worst inPⅠplot among the ten types. （2） There were no significant differences in water content, bulk density and the maximum water-holding capacity of soil amongst these forest types, with the variation ranges of 8.94%~16.54%, 1.10~1.66 ＆·cm^-3 and 200.43~266.43 t·hm^-2, respectively. However, the non-pore porosity of soil among these 10 forest types varied greatly, with a variation range of 0.99%~4.32%. The water-holding functions of soil were the highest inPⅢ andPⅣplots, and the lowest in thePⅠplot. （3） Power function model can better indicate high correlation coefficients between the water absorption rate of litter and its immersion time, and also between the water-holding cap
出处
《生态环境学报》
CSCD
北大核心
2015年第4期624-630,共7页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(30771764)
国家林业局荒漠化定位监测项目(200-628260)
关键词
枯落物
持水量
造林密度
forest litter
water-holding capacity
afforestation density
