草海流域3种优势树种凋落物叶分解历程中的水文特征

Research for Leaf-Litter Hydrographic Effect in the Decomposition Process of Three Dominant Tree Species in the Caohai Wetland Watershed

采用凋落物分解网袋法对草海湿地流域森林优势植物青冈(Cyclobalanopsisglauca)、桤木(Alnus cremastogyne)和云南松(Pinus yunnanensis)凋落物叶分解特性展开研究,揭示凋落物叶分解过程中自然持水率、最大持水率、最大拦蓄率、有效拦蓄率及凋落物持水率规律等。结果表明:(1)凋落物叶自然持水率随分解时间的增加呈先增后降趋势。凋落物叶自然持水率在分解历程中存在极显著性差异(青冈:F=213.79,P<0.01;桤木:F=77.53,P<0.01;云南松:F=179.12,P<0.01)。(2)凋落物叶持水率(Rt)与浸水时间(t)呈显著正相关关系(P<0.05),回归分析得到凋落物叶持水率(Rt)与浸水时间(t)符合对数函数方程Rt=a+blnt;凋落物叶持水速率(v)与浸水时间(t)呈显著负相关关系(P<0.05),持水速率(v)与浸水时间(t)符合幂函数方程v=at-b。(3)凋落物叶最大拦蓄率、有效拦蓄率随分解时间的推移,呈逐渐增加趋势。

The method of leaf litter decomposition bag was used to study natural water-holding rate, maximum water holding rate, maximum interception rate,modified interception rate ＆ holding water trait etc of leaf litter in decomposition process, dominant plant species Cyclobalanopsis glauca, Alnus cremastogyne ＆ Pi- nus yunnanensi in Caohai wetland watershed forest were selected as the research examples. The result showed that： （1） the leaf litter natural water-holding rate first increased and then decreased with the decom- position time extension. The leaf litter lnatural water-holding rate was highly significantly different in the de- composition process; （2） the leaf litter water-holding rate （Rt） ＆ immersion time （t） showed a significant positive correlation, the regression analysis for leaf litter water-holding rate （Rt） ＆ immersion time （t） fol- lowed the function equation Rt =a＋b1nt. The leaf litter water absorption rate （v） ＆ immersion time （t） showed a significantly negative correlation, the regression analysis for the leaf litter＇s water absorption rate （v） vs immersion time （t） can be described by the equation, v= at^-b ; （3） the leaf litter maximum intercep- tion rate, modified interception rate gradually increased with the decomposition time duration.