古尔班通古特沙漠5种植物凋落物分解特征

doi:10.7522/j.issn.1000-694X.2019.00081

摘要/Abstract

摘要： 为明确养分受限环境中凋落物的分解特征及调控因素,以古尔班通古特沙漠5种不同生活型植物粗柄独尾草(Eremurus inderiensis)、尖喙牻牛儿苗(Erodium oxyrrhynchum)、芦苇(Phragmites communis)、花花柴(Karelinia caspia)和小果白刺(Nitraria sibirica)为对象,利用分解网袋法,研究了典型植物各器官(叶、茎、根)凋落物的分解过程。结果表明:(1)不同生活型植物各器官凋落物的质量损失过程可以用负指数衰减模型较好地拟合(R²>0.70),经过629 d的分解,物种间及同一植物各器官间凋落物的分解速率存在显著差异,粗柄独尾草和尖喙牻牛儿苗的分解快于芦苇、花花柴和小果白刺,5种植物叶、根凋落物的分解快于茎,而叶和根分解的快慢具有明显的种间差异;(2)凋落物分解过程中N、P养分动态因物种、器官类型而异,5种植物茎凋落物呈现不同程度的养分固持,而粗柄独尾草和尖喙牻牛儿苗的叶、根表现为N、P养分的净释放;(3)初始化学组成对根、茎凋落物分解的影响比叶重要,其中,初始养分含量和难降解成分是限制根分解的主要因子。凋落物初始化学组成是预测温带荒漠凋落物分解的重要因素,而其重要性受植物生活型和器官类型的影响,因此,未来气候变化下,植物物种或植物生物量分配的变化所引起的凋落物质量改变,可能会对荒漠生态系统碳和养分循环产生较大影响。

关键词: 荒漠生态系统, 生活型, 凋落物分解, 分解速率, 养分动态

Abstract: Litter decomposition is one of the key processes in nutrient cycles in temperate deserts. The objectives of this study were to explore the litter decomposition characteristics of four plant life-forms, comprising five typical desert species. Litterbag experiment was carried out to investigate the decomposition characteristics of leaf, stem and root litters of Eremurus inderiensis, Erodium oxyrrhynchum, Phragmites communis, Karelinia caspia and Nitraria sibirica in the Gurbantunggut Desert, northwestern China. Litter mass loss were well described by an exponential decay model (R²>0.70). Decomposition rates were significantly different among species and organs within species. The decomposition rate of E. oxyrrhynchum and E. inderiensis were faster than that of P. communis, K. caspia and N. sibirica after 629 days of decomposition. Leaf and root decomposition were faster than stem, whereas the difference between leaf and root decomposition differed in terms of the plant. In addition, the nutrient release dynamics depended on species and plant organ. Stem generally exhibited nutrient accumulation, while leaf and root of E. inderiensis and E. oxyrrhynchum showed N and P releases. Initial chemical composition was more important in predicting decomposition rates or patterns of stem and root than leaf. Root decomposition was primarily determined by initial nutrient content and the content of recalcitrant compounds of litter. Results suggest that initial chemistry composition plays an important role in litter decomposition in temperate deserts, and the decomposability of desert litters depends on plant life-form and organ. Thus, changes in plant species or in allocation patterns among organs due to litter quality change could have profound effects on carbon and nutrient turnover in desert ecosystems.

Key words: desert ecosystem, life form, litter decomposition, decomposition rate, nutrient dynamics

中图分类号:

Q948.1

赵红梅, 程军回, 张文太, 苏延桂, 张彩云, 盛建东. 古尔班通古特沙漠5种植物凋落物分解特征[J]. 中国沙漠, 2020, 40(2): 165-176.

Zhao Hongmei, Cheng Junhui, Zhang Wentai, Su Yangui, Zhang Caiyun, Sheng Jiandong. Litters decomposition characteristics of five species in the Gurbantunggut Desert[J]. Journal of Desert Research, 2020, 40(2): 165-176.

参考文献

[1] Swift M J,Heal O W,Anderson J M.Decomposition in Terrestrial Ecosystems[M].Los Angeles USA:University of California Press,1979.
[2] Austin A T,Vivanco L.Plant litter decomposition in a semi-arid ecosystem controlled by photodegradation[J].Nature,2006,442:555-558.
[3] Freschet G T,Aerts R,Cornelissen J H C.A plant economics spectrum of litter decomposability[J].Functional Ecology,2012,26(1):56-65.
[4] Zhang D Q,Hui D F,Luo Y Q,et al.Rates of litter decomposition in terrestrial ecosystems:global patterns and controlling factors[J].Journal of Plant Ecology,2008,1:85-93.
[5] Cepeda-Pizarro J G,Whitford W G.Decomposition patterns of surface leaf litter of six plant species along a Chihuahuan Desert watershed[J].American Midland Naturalist,1990,123:319-330.
[6] Murphy K L,Klopatek J M,Klopatek C C.The effects of litter quality and climate on decomposition along an elevational gradient[J].Ecological Applications,1998,8:1061-1071.
[7] Strickland M S,Osburn E,Lauber C,et al.Litter quality is in the eye of the beholder:initial decomposition rates as a function of inoculum characteristics[J].Functional Ecology,2009,23:627-636.
[8] 毕京东,李玉霖,宁志英,等.科尔沁沙地优势植物叶凋落物分解及碳矿化:凋落物质量的影响[J].中国沙漠,2016,36(1):85-92.
[9] Brand L A,King J Y,Hobbie S E,et al.The role photodegradation in surface litter decomposition across a grassland ecosystem precipitation gradient[J].Ecosystems,2010,13:765-781.
[10] Erdenebileg E,Ye X H,Wang C W,et al.Positive and negative effects of UV irradiance explain interaction of litter position and UV exposure on litter decomposition and nutrient dynamics in a semi-arid dune ecosystem[J].Soil Biology & Biochemistry,2018,124:245-254.
[11] Cornwell W K,Cornelissen J H C,Amatangelo K,et al.Plant species traits are the predominant control on litter decomposition rates within biomes worldwide[J].Ecology Letters,2008,11:1065-1071.
[12] Roumet C,Birouste M,Picon-Cochard C,et al.Root structure-function relationship in 74 species:evidence of a root economics spectrum related to carbon economy[J].New Phytologist,2016,210:815-826.
[13] Dorrepaal E,Cornelissen J H C,Aerts R,et al.Are growth forms consistent predictors of leaf litter quality and decomposability across peatlands along a latitudinal gradient[J].Journal of Ecology,2005,93:817-828.
[14] Vivanco L,Austin A T.Intrinsic effects of species on leaf litter and root decomposition:a comparison of temperate grass species from North and South America[J].Oecologia,2006,150:97-107.
[15] Fujii S,Takeda H.Dominant effects of litter substrate quality on the difference between leaf and root decomposition process above- and belowground[J].Soil Biology & Biochemistry,2010,42:2224-2230.
[16] Silver W L,Miya R K.Global patterns in root decomposition:comparisons of climate and litter quality effects[J].Oecologia,2001,129:407-419.
[17] Weedon J T,Cornwell W K,Cornelissen J H C,et al.Global meta-analysis of wood decomposition rates:a role for trait variation among tree species[J].Ecology Letters,2009,12:45-56.
[18] Gholz H L,Wedin D A,Smitherman S M,et al.Long-term dynamics of pine and hardwood litter in contrasting environments:toward a global model of decomposition[J].Global Change Biology,2000,6:751-765.
[19] Moretto A S,Distel R A,Didoné N G.Decomposition and nutrient dynamics of leaf litter and roots from palatable and unpalatable grasses in a semi-arid grassland[J].Applied Soil Ecology,2001,18:31-37.
[20] Hobbie S E,Oleksyn J,Eissenstat D M,et al.Fine root decomposition rates do not mirror those of leaf litter among temperate tree species[J].Oecologia,2010,162(2):505-513.
[21] 王雪芹,蒋进,雷加强,等.短命植物分布与沙垄表层土壤水分的关系:以古尔班通古特沙漠为例[J].应用生态学报,2004,15:556-560.
[22] 顾峰雪,张远东,潘晓玲,等.阜康绿洲土壤盐渍化与植物群落多样性的相关性分析[J].资源科学,2002,24:42-48.
[23] 张立运,陈昌笃.论古尔班通古特沙漠植物多样性的一般特点[J].生态学报,2002,22:1923-1932.
[24] 李成道,李向义,Sun H J,等.极端干旱区花花柴(Karelinia caspia)、骆驼刺(Alhagi sparsifolia)和胡杨(Populus euphratica)叶片凋落物分解特征[J].中国沙漠,2019,39(2):193-201.
[25] Olson J S.Energy storage and the balance of producers and decomposers in ecological systems[J].Ecology,1963,44(2):322-331.
[26] Chen J H,Chu P F,Chen D M,et al.Functional correlations between species leaf area and specific root length along a regional environmental gradient in Inner Mongolia grasslands[J].Functional Ecology,2016,30:985-997.
[27] McClaugherty C A,Aber J D,Melillo J M.Decomposition dynamics of fine roots in forested ecosystems[J].Oikos,1984,42:378-386.
[28] Martínez-Yrízar A,Núňez S,Búrquez A.Leaf litter decomposition in a southern Sonoran Desert ecosystem,northwestern Mexico:effects of habitat and litter quality[J].Acta Oecologica,2007,32:291-300.
[29] Uselman S M,Snyder K A,Blank R R,et al.UVB exposure does not accelerate rates of litter decomposition in a semi-arid riparian ecosystem[J].Soil Biology & Biochemistry,2001,43:1254-1265.
[30] Reich P B.The world-wide 'fast-slow’ plant economics spectrum:a trait manifesto[J].Journal of Ecology,2014,102:275-301.
[31] Reich P B,Walters M B,Ellsworth D S.From tropics to tundra:global convergence inplant functioning[J].Proceedings of the National Academy of Sciences of the United States of America,1997,94:13730-13734.
[32] Gliksman D,Hanenel S,Grünzweig M J.Biotic and abiotic modifications of leaf litter during dry periods affect litter mass loss and nitrogen loss during wet periods[J].Functional Ecology,2018,32:831-839.
[33] Melillo J M,Aber J D,Muratore J F.Nitrogen and lignin control of hardwood leaf litter decomposition dynamics[J].Ecology,1982,63:621-626.
[34] 张瑞,周晓兵,张元明.生物土壤结皮对温带荒漠植物凋落物分解的影响[J].中国沙漠,2019,39(6):151-158.
[35] 刘文丹,陶建平,张腾达,等.中亚热带木本植物各器官凋落物分解特性[J].生态学报,2014,34(17):4850-4858.
[36] Vanholme R,Demedts B,Morreel K,et al.Lignin biosynthesis and structure[J].Plant Physiology,2010,153:895-905.
[37] Moorhead D L,Reynolds J F.Mechanisms of surface litter mass loss in the northern Chihuahuan Desert:a reinterpretation[J].Journal of Arid Environments,1989,16:157-163.
[38] Manzoni S,Trofymow J A,Jackson R B,et al,Stoichiometric controls on carbon,nitrogen,and phosphorus dynamics in decomposing litter[J].Ecological Monographs,2010,80:89-106.
[39] Moore T R,Trofymow J A,Prescott C E,et al.Nature and nurture in the dynamics of C,N and P during litter decomposition in Canadian forests[J].Plant & Soil,2011,339:163-175.
[40] Frey S,Elliott E,Paustian K,et al.Fungal translocation as a mechanism for soil nitrogen inputs to surface residue decomposition in a no-tillage agroecosystem[J].Soil Biology & Biochemistry,2000,32:689-698.
[41] Parton W,Silver W L,Burke I C,et al.Global-scale similarities in nitrogen release patterns during long-term decomposition[J].Science,2007,315:361-364.
[42] Moore T R,Trofymow J A,Prescott C E,et al.Patterns of C,N and P dynamics in decomposing foliar litter in Canadian forests[J].Ecosystems,2006,9:46-62.
[43] Manzoni S,Jackson R B,Trofymow J A,et al.The global stoichiometric of litter nitrogen mineralization[J].Science,2008,321:684-686.
[44] Osono T,Takeda H.Accumulation and release of nitrogen and phosphorus in relation to lignin decomposition in leaf litter of 14 tree species[J].Ecological Research,2004,19:593-602.