贵州百里杜鹃自然保护区杜鹃林枯落物储量及持水功能

为揭示贵州百里杜鹃自然保护区人工抚育及旅游管理对杜鹃林水土保持功能的影响,选择轻度、中度、重度干扰强度的杜鹃林枯落物层作为研究对象,采用室内浸泡法对不同干扰强度的杜鹃林枯落物层水文功能进行研究。结果表明:(1)杜鹃林枯落物储量随干扰强度增加呈降低趋势,随分解程度增加呈极显著升高趋势;自然含水率随干扰强度增加呈降低趋势,随分解程度增加总体呈升高趋势。(2)杜鹃林枯落物最大持水量随干扰强度增加呈降低趋势,随分解程度增加呈极显著升高趋势。枯落物最大拦蓄量、最大拦蓄率、有效拦蓄量及有效拦蓄率均随干扰强度增加呈升高趋势。(3)枯落物层持水量变化特征呈倒"J"形。持水量(Q)与浸水时间(t)呈显著正相关关系(P0.05),其回归方程为Q=b+aln t。枯落物浸水0~4h内持水量逐渐增加,4~48h持水量增加趋势大幅减缓,并逐渐趋于饱和。(4)枯落物层吸水速率呈"急剧降低—迅速降低—缓慢降低—趋于稳定"的变化特征。吸水速率(v)与浸水时间(t)均呈极显著负相关关系(P0.01),其回归方程为v=at-b。枯落物在1h内发挥其水文功能的能力最强,对短时段内的降雨截流调蓄功能最大。

Litter Reserves and Water Holding Characteristics of Rhododendron Forest in Baili Rhododendron Nature Reserve of Guizhou

This study, taking the litter layer of rhododendron forest with mild, moderate, and severe interference intensity as the research object, analyzed the hydrological function characteristics of the litter layer of different interference intensity on the basis of indoor immersion method, aimed to reveal the influence of artificial tending and tourism management on the function of soil and water conservation of rhododendron forest in Baili Rhododendron nature reserve. The results showed that:(1) The litter reserves decreased with the increase of interference intensity, while it increased significantly with the increase of decomposition degree; natural moisture content decreased with the increase of interference intensity, and increased with the increase of decomposition degree. (2) The maximum water-holding capacity of rhododendron forest litter decreased with the increase of interference intensity, and increased significantly with the increase of decomposition degree. The maximum interception amount, maximum interception rate, effective interception amount, and effective interception rate of litter rose with the increase of interference intensity. (3) The water-holding capacity variation of litter layer manifested as an inverted "J" feature. The water-holding capacity of litter layer (Q) was positively correlated with soaking time (t) (P<0.05), and the regression equation was Q=b+aln t. The water-holding capacity increased gradually in the soaking time interval of 0~4 h, whereas the increase rate became slow in 4~48 h and then approached to saturation. (4) The water absorption rate of the litter layer was characterized by the cycles of "sharp reduction-rapid reduction-slow reduction-tending to stabilization". The water absorption rate (v) was significantly negative correlated with soaking time (t)(P<0.01), and the regression equation was v=at^-b. The litter had the strongest ability to play its hydrological function in 1h and showed the greatest function of rainfall interception in a short period of time.