极端干旱区花花柴(Karelinia caspia)和胡杨(Populus euphratica)叶凋落物分解和养分释放特征  

Decomposition and nutrient release characteristics of Karelinia caspia and Populus euphratica leaf litters in extreme arid regions

作　　者：范琳杰 李向义[1,3] 李成道 林丽莎 薛伟[5] FAN Linjie;LI Xiangyi;LI Chengdao;LIN Lisha;XUE Wei(Xinjiang Key laboratory of Desert Plant Roots Ecology and Vegetation Restoration,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;Cele National Field Science Observation and Research Station of Desert Grassland Ecosystem,Cele 848300,Xinjiang,China;University of Chinese Academy of Science,Beijing 100049,China;Lanzhou University,Lanzhou 730000,Gansu,China)

机构地区：[1]中国科学院新疆生态与地理研究所,新疆荒漠植物根系生态与植被修复重点实验室,新疆乌鲁木齐830011 [2]中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,新疆乌鲁木齐830011 [3]新疆策勒荒漠草地生态系统国家野外科学观测实验站,新疆策勒848300 [4]中国科学院大学,北京100049 [5]兰州大学,甘肃兰州730000

出　　处：《干旱区研究》2021年第2期479-486,共8页Arid Zone Research

基　　金：国家自然科学基金项目(41877420);新疆维吾尔自治区天池百人计划-创新项目(Y842041);新疆科技创新基地建设项目(PT1908)。

摘　　要：为研究凋落物在极端干旱区的分解规律,利用凋落物分解袋法,以塔克拉玛干沙漠南缘策勒绿洲地区优势物种花花柴(Karelinia caspia)和胡杨(Populus euphratica)叶凋落物为研究对象,模拟自然状态,分别在3种生境下:土壤表层0 cm、土壤埋深2 cm、悬挂1 m进行凋落物分解试验,探究不同分解位置下的凋落物质量分解和碳(C)、氮(N)元素含量释放特征。结果表明:不同植物的质量损失率在不同分解位置处理下均存在显著差异,土壤表层0 cm处理下凋落物质量损失显著高于悬挂1 m和土壤埋深2 cm。至凋落物分解试验结束,花花柴质量损失率依次为:土壤表层0 cm(19.91%)>悬挂1 m(15.99%)>土壤埋深2 cm(12.35%)。胡杨质量损失率依次为:土壤表层0 cm(24.15%)>悬挂1 m(13.44%)>土壤埋深2 cm(8.72%)。在整个分解过程中,两种植物叶凋落物N含量呈富集现象,C含量呈释放状态。在不同分解位置下,N元素富集量和C元素量损失差异显著,土壤表层和土壤埋深2 cm凋落物N元素富集量均小于悬挂1 m凋落物,C元素损失量均大于悬挂1 m凋落物。Olson指数衰减模型对凋落物质量残留率进行拟合,两种植物的分解常数k值大小排序均为:土壤表层0 cm>悬挂1 m>土壤埋深2 cm。凋落叶质量残留率多因素方差分析表明在不同分解时间和不同分解位置对凋落物质量残留率影响显著(P<0.01)。在极端干旱区,掩埋条件不是驱动凋落物分解的主要因素,影响凋落物分解的因素主要是光降解。In arid regions,strong solar radiation and photodegradation or physical degradation accelerate the rate of litter decomposition.However,research on the decomposition of litter in extreme arid regions remains limited.In this study,we investigated the litter decomposition rate of plant species in extreme arid regions using the litter bag method.Karelinia caspia and Populus euphratica are two dominant species in Cele Oasis located at the southern margin of the Taklimakan Desert.Litter decomposition tests of K.caspia and P.euphratica were carried out in three habitats(aboveground,2 cm belowground and hanging 1 m)to explore the mass decomposition of litters and the release of carbon(C)and nitrogen(N)from the litters in each habitat.The mass decomposition rates of K.caspia and P.euphratica showed significant differences at different depths;the mass loss of aboveground(0 cm)litter was significantly higher than that of 1 m hanging and 2 cm belowground litters.At the end of the litter decomposition test,the mass loss of K.caspia and P.euphratica wood was in the order:aboveground(19.91%)>1 m hanging(15.99%)>2 cm belowground(12.35%)and aboveground(24.15%)>1 m hanging(13.44%)>2 cm belowground(8.72%),respectively.During the entire decomposition process,the N content of litters of both plant species increased,whereas the C content decreased.At different decomposition positions,the enrichment of N and the loss of C varied significantly.The enrichment of N in aboveground and belowground litters was lower than that of hanging litters,whereas the loss of C from above-and belowground litters was greater than that from hanging litters.Olson’s exponential attenuation model was used to fit the mass residual rate of litters.The order of the decomposition constant(k)of the two plant species was in the order:aboveground>hanging>belowground.Additionally,multivariate analysis of the variance of mass residual rate of litters showed that both decomposition time and decomposition position had significant effects on the mass residual rate of

关 键 词：凋落物分解 质量损失 极端干旱 养分释放 

分 类 号：Q948[生物学—植物学]