百里杜鹃林区马缨杜鹃凋落物花叶混合比例对分解的影响  

Impacts on Decomposition of Flower to Leaf Ration in the Litter of Rhododendron delavayi in Baili Azalea Forest Area of Guizhou Province

作　　者：田奥 王加国 韩振诚 吴佳伟 李苇洁 Tian Ao;Wang Jiaguo;Han Zhencheng;Wu Jiawei;Li Weijie(Research Institute of Mountain Resource of Guizhou Province, Guiyang 550001;College of Forestry,Guizhou University, Guiyang 550025)

机构地区：[1]贵州省山地资源研究所,贵阳550001 [2]贵州大学林学院,贵阳550025

出　　处：《林业科学》2020年第8期1-10,共10页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(41561109)。

摘　　要：【目的】百里杜鹃是贵州毕节的重要旅游资源,其凋落物和林地枯落物层发挥着保护土壤、固碳、涵养水源等多种生态功能。杜鹃花有良好的药用价值,收集鲜花凋落物是实现其药用价值的主要途径。本研究以贵州毕节百里杜鹃林区优势树种马缨杜鹃为例,量化不同花叶比例凋落物混合的非加和效应,建立凋落物分解模型并模拟凋落物分解动态,以期为确定花凋落物合理收集强度提供理论依据。【方法】在固定样地布设不同花叶比例的混合凋落物分解网袋420个,即花干质量比例分别为0(纯叶)、10%、20%、30%、40%、50%、100%(纯花)7个处理,每个处理60个重复,在1年内每2个月测1次样品质量损失率;然后,基于Olson方程,构建凋落物分解残留率随花比例及分解时间变化的模型。【结果】马缨杜鹃的花叶混和凋落物的分解残留率随分解时间及花比例增加而降低,分解1年后的残留率在花比例为0、10%、20%、30%、40%、50%和100%时分别为63.1%、58.7%、60.2%、56.8%、56.2%、55.5%和55.2%;凋落物的阶段分解率在0~61天内最大(0.054 g·d^-1),在62·183天内迅速降至0.017 g·d^-1,在184~306天内回升至0.024 g·d^-1,在307~365天内大幅降至0.005 g·d^-1;存在混合凋落物的非加和效应且表现为促进分解作用,在花比例10%、20%、30%、40%和50%的处理中,非加和效应最大值分别为分解365天后的7.8%、365天后的4.7%、330天后的6.9%、310天后的6.8%和270天后的6.6%;建立了考虑凋落物混合的非加和效应的凋落物分解残留率模型,拟合精度高达0.987;模拟分析表明,花比例80%时的凋落物累积分解率最高,1年后可达48%;当花比例为接近自然比例的20%和人为降低的15%、10%、5%和0时,分解1年后的模拟残留率分别为60.0%、61.3%、62.8%、64.4%和66.1%;野外实测分解1年后,花比例10%处理的残留率平均值为58.7%,花比例20%(接近自然比例)处理的残留率平均值为6【Objective】Litters decomposition is an important process for the material cycling and energy flow in ecosystems.The mixture of litter components will have a non-additive effect on the decomposition rate,i.e.,the decomposition rate of mixed litter is higher or lower than the weighted average of the decomposition rates of all single components.The Rhododendron delavayi forests are important sightseeing resources in the Baili Azalea Forest Area in Bijie,Guizhou Province of China.The litters and humus layer of these forests exert numerous ecological services,such as soil erosion control,carbon sequestration,and water regulation.Especially,the flower has good pharmaceutical value.Collecting fresh flower litter during the flowering season is the main approach to use this pharmaceutical value.However,an urgentissue is to determine the rationalintensity of flower collection with a precondition of no obvious effect on litter decomposition so that the structure and functions of the humus layer can be maintained.In this decomposition study of the litter of R.delavayi,a dominant species of the azalea forests,the non-additive effect in the treatments with different flower-leaf ratios was quantified,a decomposition model was developed and used to simulate the decomposition response to the variation of flower-leaf ratio,and the rational intensity of flower litter collection was explored.【Method】A one year field decomposition study was implemented in fixed plots with 420 mesh bags filled with mixed litter of 7 treatments.These treatments had a flower dry weight ratio of 0(pure leaves),10%,20%,30%,40%,50%,100%(pure flowers).Each treatment had 60 repeats.The loss of litter mass was measured in every two months.A litter decomposition model was set up based on the Olson equation to illustrate the litter decomposition response to the flower ratio and decomposition time.【Result】The remaining rate of mixed litter treatments decreased with rising decomposition time and flower ratio.For the flower ratios of 0,10%,20%,30%,40%,

关 键 词：马缨杜鹃 凋落物 花比例 分解速率 花利用 

分 类 号：S154.5[农业科学—土壤学] Q958.15[农业科学—农业基础科学]