氮添加对亚热带次生常绿阔叶林扁刺栲细根生物量、寿命和形态的短期影响

doi:10.17521/cjpe.2016.0317

摘要/Abstract

摘要：

细根在植物的养分获取和生态系统物质循环中有重要的作用, 日益增加的氮沉降改变了土壤pH值和养分可利用性, 潜在地影响着细根特性。为揭示氮沉降增加对木本植物细根寿命和形态的影响, 于2013年5月至2015年9月在亚热带次生常绿阔叶林中开展每月一次的氮添加试验, 共设对照(CK, 0 g·m^-2·a^-1)、低氮(LN, 5 g·m^-2·a^-1)、高氮(HN, 15 g·m^-2·a^-1) 3个水平。以该林分建群种扁刺栲(Castanopsis platyacantha)为研究对象, 于2014年4月至2015年9月, 每月采用微根管技术获取根系影像, 室内分析后得到各样地的扁刺栲细根生物量、寿命和形态指标。2014年11月取0-10 cm土壤分析土壤pH值、铵态氮和硝态氮含量。结果表明: 扁刺栲0-45 cm土层细根生物量为128.30 g·m^-3, 细根平均寿命范围为113-186天; 氮添加处理未显著影响扁刺栲0-45 cm土层细根寿命和生物量; 低氮处理显著降低了0-15 cm土层细根根段表面积; 高氮处理显著降低了表层土壤pH值。研究表明短期氮添加通过影响该次生林土壤无机氮含量, 导致表层土壤酸化, 对表层土壤扁刺栲细根的形态特征造成一定的影响; 短期氮添加对扁刺栲细根生物量、寿命和深层细根的形态未产生显著影响。

关键词: 氮沉降, 细根生物量, 细根寿命, 细根形态, 微根管

Abstract:

Aims Fine roots are the principal parts for plant nutrients acquisition and play an important role in the underground ecosystem. Increased nitrogen (N) deposition has changed the soil environment and thus has a potential influence on fine roots. The purpose of this study is to reveal the effect of N deposition on biomass, lifespan and morphology of fine root.Methods A field N addition experiment was conducted in a secondary broad-leaved forest in subtropical China from May 2013 to September 2015. Three levels of N treatments: CK (no N added), LN (5 g·m^-2·a^-1), and HN (15 g·m^-2·a^-1) were applied monthly. Responses of fine root biomass, lifespan, and morphology of Castanopsis platyacantha to N addition were analyzed by using a minirhizotron image system from April 2014 to September 2015. Surface soil sample (0-10 cm) was collected in November 2014 and soil pH value, and concentrations of NH₄⁺-N and NO₃^--N were measured.Important findings The biomass and average lifespan of the fine roots of C. platyacantha were 128.30 g·m^-3and 113-186 days, respectively, in 0-45 cm soil layer. Nitrogen addition had no significant effect on either fine root biomass or lifespan in 0-45 cm soil layer. However, LN treatment significantly decreased C. platyacantha root superficial area in 0-15 cm soil layer. HN treatment significantly decreased soil pH value. Our study indicated that short-term N addition influences soil inorganic N concentration and thus decreased pH value in surface soil, and thereafter affect fine root morphology. Short-term N addition, however, did not affect the fine root biomass, lifespan and morphology in subsoil.

Key words: nitrogen deposition, fine root biomass, fine root lifespan, fine root morphology, minirhizotron

陈冠陶, 彭勇, 郑军, 李顺, 彭天驰, 邱细容, 涂利华. 氮添加对亚热带次生常绿阔叶林扁刺栲细根生物量、寿命和形态的短期影响. 植物生态学报, 2017, 41(10): 1041-1050. DOI: 10.17521/cjpe.2016.0317

Guan-Tao CHEN, Yong PENG, Jun ZHENG, Shun LI, Tian-Chi PENG, Xi-Rong QIU, Li-Hua TU. Effects of short-term nitrogen addition on fine root biomass, lifespan and morphology of Castanopsis platyacantha in a subtropical secondary evergreen broad-leaved forest. Chinese Journal of Plant Ecology, 2017, 41(10): 1041-1050. DOI: 10.17521/cjpe.2016.0317

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https://www.plant-ecology.com/CN/Y2017/V41/I10/1041

图/表 6

表1 瓦屋山次生常绿阔叶林土壤理化性质(平均值±标准误差)

Table 1 Soil physicochemical properties in a secondary evergreen broad-leaved forest, Wawu Mountain (mean ± SE)

土层深度 Soil depth (cm)	pH	土壤容重 Soil bulk density (g·cm^-3)	有机碳含量 Organic carbon content (g·kg^-1)	全氮含量 Total nitrogen content (g·kg^-1)	全磷含量 Total phosphorus content (g·kg^-1)	全钾含量 Total potassium content (g·kg^-1)
0-10	3.19 ± 0.03	0.41 ± 0.03	121.9 ± 11.7	5.80 ± 0.30	0.50 ± 0.01	13.89 ± 0.92
10-40	3.76 ± 0.03	0.66 ± 0.02	26.6 ± 2.5	1.51 ± 0.08	0.26 ± 0.03	17.07 ± 0.82
40-70	3.97 ± 0.02	0.89 ± 0.03	12.6 ± 1.2	0.82 ± 0.05	0.18 ± 0.01	19.02 ± 1.17
70-100	4.03 ± 0.02	0.99 ± 0.03	7.8 ± 0.8	0.57 ± 0.04	0.21 ± 0.01	19.31 ± 1.26

表2 氮添加对表层土壤(0-10 cm)化学养分和pH值的影响(平均值±标准误差)

Table 2 The effect of N addition on surface soil (0-10 cm) chemical element and pH value (mean ± SE)

	pH	TN (g·kg^-1)	NH₄⁺-N (mg·kg^-1)	NO₃^--N (mg·kg^-1)
CK	3.99 ± 0.05^a	6.62 ± 0.50	25.62 ± 5.79	25.47 ± 3.90
LN	3.82 ± 0.02^ab	7.19 ± 0.57	21.63 ± 6.02	26.27 ± 4.65
HN	3.78 ± 0.08^b	7.23 ± 0.35	40.15 ± 12.39	36.69 ± 4.61
单因素方差分析 One-way ANOVA analysis	p = 0.04	p = 0.62	p = 0.33	p = 0.21

表3 I层(0-15 cm)扁刺栲细根形态指标、中值寿命和表层土壤(0-10 cm)理化指标相关分析结果

Table 3 Layer I (0-15 cm) correlation analysis results of Castanopsis platyacantha fine root morphology index, median lifespan, and soil physicochemical property (0-10 cm)

	中值寿命 Median lifespan	pH	总氮 Total nitrogen	NH₄⁺-N	NO₃^--N	根段长 Root segment length	根段表面积 Root segment surface-area
pH	0.84^**
总氮 Total nitrogen	-0.54	-0.57
NH₄⁺-N	-0.34	-0.75^*	0.45
NO₃^--N	-0.41	-0.67^*	0.54	0.72^*
根段长 Root segment length	0.37	0.35	-0.15	0.01	-0.18
根段表面积 Root segment surface-area	0.73^*	0.74^*	-0.50	-0.24	-0.50	0.76^*
根直径 Root diameter	0.48	0.47	-0.32	-0.27	-0.14	-0.48	0.15

图1 不同土层细根生物量(平均值±标准误差)。CK, 对照 (0 g·m-2·a-1); LN, 低氮(5 g·m-2·a-1); HN, 高氮(15 g·m-2·a-1)。p值为不同土层单因素方差分析的结果。

Fig. 1 Fine root biomass in different soil layer (mean ± SE). CK, control (0 g·m-2·a-1); LN, low nitrogen addition (5 g·m-2·a-1); HN, high nitrogen addition (15 g·m-2·a-1). p value is the results of one-way ANOVA analysis in different soil layer.

图2 氮添加对不同土层细根生存曲线的影响。p值为氮添加处理对同一土层细根生存曲线的显著性检验结果。CK, 对照; LN, 低氮; HN, 高氮。

Fig. 2 Effects of nitrogen additions on fine root survival curve. p values are the survival curves significance test result of N addition in the same soil layers. CK, control; LN, low nitrogen; HN, high nitrogen.

图3 氮添加对不同土层细根直径、根段数、根段长、根段表面积的影响(平均值±标准误差)。CK, 对照; LN, 低氮; HN, 高氮。图中文字为对应土层的单因素方差分析结果; 图中字母表示氮添加处理对同一土层各形态指标的单因素方差分析结果。

Fig. 3 Effects of nitrogen additions on fine root diameter, length and superficial area at different soil layers (mean ± SE). CK, control; LN, low nitrogen; HN, high nitrogen. Text and letters in figure are the result of one-way ANOVA analysis on same morphology indexes in the same soil layers.

参考文献 47

[1]	Addo-Danso SD, Prescott CE, Smith AR (2016). Methods for estimating root biomass and production in forest and woodland ecosystem carbon studies: A review.Forest Ecology and Management, 359, 332-351. DOI URL
[2]	Balogianni VG, Blume-Werry G, Wilson SD (2016). Root production in contrasting ecosystems: The impact of rhizotron sampling frequency.Plant Ecology, 217, 1-9. DOI URL
[3]	Bao SD (2000).Soil Agricultural Chemistry Analysis. 3rd edn. China Agriculture Press, Beijing. (in Chinese)[鲍士旦 (2000).土壤农化分析. 第三版. 中国农业出版社, 北京.]
[4]	Bardgett RD, Mommer L, de Vries FT (2014). Going underground: Root traits as drivers of ecosystem processes.Trends in Ecology & Evolution, 29, 692-699. DOI URL PMID
[5]	Bedison JE, Mcneil BE (2009). Is the growth of temperate forest trees enhanced along an ambient nitrogen deposition gradient?Ecology, 90, 1736-1742. DOI URL PMID
[6]	Burton AJ, Pregitzer KS, Hendrick RL (2000). Relationships between fine root dynamics and nitrogen availability in Michigan northern hardwood forests. Oecologia, 125, 389-399. DOI URL PMID
[7]	Chen GT, Tu LH, Peng Y, Hu HL, Hu TX, Xu ZF, Liu L, Tang Y (2017). Effect of nitrogen additions on root morphology and chemistry in a subtropical bamboo forest.Plant and Soil, 412, 441-451. DOI URL
[8]	Chen HYH, Brassard BW (2013). Intrinsic and extrinsic controls of fine root life span.Critical Reviews in Plant Sciences, 32, 151-161. DOI URL
[9]	Chen YT, XU ZZ (2014). Review on research of leaf economics spectrum. Chinese Journal of Plant Ecology, 38, 1135-1153. (in Chinese with English abstract)[陈莹婷, 许振柱 (2014). 植物叶经济谱的研究进展. 植物生态学报, 38, 1135-1153.] DOI URL
[10]	Chirici G, Corona P, Portoghesi L (2013). Global forest resources assessment.Italian Journal of Forest & Mountain Environments, 56, 12-64.
[11]	Eissenstat DM, Wells CE, Yanai RD, Whitbeck JL (2000). Building roots in a changing environment: Implications for root longevity.New Phytologist, 147, 33-42. DOI URL
[12]	Eissenstat DM, Yanai RD (1997). The ecology of root lifespan.Advances in Ecological Research, 27, 1-60. DOI URL
[13]	Evans CD, Norris D, Ostle N, Grant H, Rowe EC, Curtis CJ, Reynolds B (2008). Rapid immobilisation and leaching of wet-deposited nitrate in upland organic soils.Environment Pollution, 156, 313-319. DOI URL PMID
[14]	Galloway JN, Cowling EB (2002). Reactive nitrogen and the world: 200 years of change.Ambio, 31, 64-71. DOI URL PMID
[15]	Galloway JN, Dentener FJ, Capone DG, Boyer EW, Howarth RW, Seitzinger SP, Asner GP, Cleveland CC, Green PA, Holland EA, Karl DM, Michaels AF, Porter JH, Townsend AR, V?r?smarty CJ (2004). Nitrogen cycles: Past, present, and future.Biogeochemistry, 70, 153-226.
[16]	Hou X, Duan C, Tang CQ, Fu D (2010). Nutrient relocation, hydrological functions, and soil chemistry in plantations as compared to natural forests in central Yunnan, China.Ecological Research, 25, 139-148. DOI URL
[17]	Huang J, Mo J, Zhang W, Lu X (2014). Research on acidfication in forest soil driven by atmospheric nitrogen deposition.Acta Ecologica Sinica, 34, 302-310. DOI URL
[18]	Huang JX, Ling H, Yang ZJ, Lu ZL, Xiong DC, Chen GS, Yang YS, Xie JS (2012). Estimating fine root production and mortality in subtropicalAltingia grlilipes and Castanopsis carlesii forests. Acta Pedologica Sinica, 14, 4472-4480. (in Chinese with English abstract)[黄锦学, 凌华, 杨智杰, 卢正立, 熊德成, 陈光水, 杨玉盛, 谢锦升 (2012). 中亚热带细柄阿丁枫和米槠群落细根的生产和死亡动态. 生态学报, 14, 4472-4480.] DOI URL
[19]	Jackson RB, Mooney HA, Schulze ED (1997). A global budget for fine root biomass, surface area, and nutrient contents.Proceedings of the National Academy of Sciences of the United States of America, 94, 7362-7366. DOI URL PMID
[20]	Johnson MG, Phillips DL, Tingey DT, Storm MJ (2000). Effects of elevated CO2, N-fertilization, and season on survival of ponderosa pine fine roots.Canadian Journal of Forest Research, 30, 220-228. DOI URL
[21]	Jourdan C, Silva EV, Goncalves JLM, Ranger J, Moreira RM, Laclau JP (2008). Fine root production and turnover inBrazilian Eucalyptus plantations under contrasting nitrogen fertilization regimes. Forest Ecology and Management, 256, 396-404.
[22]	Kou L, Guo D, Yang H, Gao W, Li S (2015). Growth, morphological traits and mycorrhizal colonization of fine roots respond differently to nitrogen addition in a slash pine plantation in subtropical China.Plant and Soil, 391, 207-218. DOI URL
[23]	Lebauer DS, Treseder KK (2008). Nitrogen limitation of net primary productivity in terrestrial ecosystems is globally distributed.Ecology, 89, 371-379.
[24]	Li D, Chen HW, Li GQ, Yang B, Meng M, Shi FQ (2011). Comparative analysis of artificial forest and natural forest in China.Forest Inventory and Planning, 36(6), 59-63. (in Chinese with English abstract)[李丹, 陈宏伟, 李根前, 杨斌, 孟梦, 史富强 (2011). 我国天然林与人工林的比较研究. 林业调查规划, 36(6), 59-63.]
[25]	Li JY, Wang MB, Shi JW (2007). Minirhizotron technique in measuring fine root indices: A review.Chinese Journal of Ecology, 26, 1842-1848. (in Chinese with English abstract)[李俊英, 王孟本, 史建伟 (2007). 应用微根管法测定细根指标方法评述. 生态学杂志, 26, 1842-1848.]
[26]	Li W, Jin C, Guan D, Wang Q, Wang A, Yuan F, Wu J (2015). The effects of simulated nitrogen deposition on plant root traits: A meta-analysis.Soil Biology and Biochemistry, 82, 112-118. DOI URL
[27]	Lucas RW, Klaminder J, Futter MN, Bishop KH, Egnell G, Laudon H, Hogberg P (2011). A meta-analysis of the effects of nitrogen additions on base cations: Implications for plants, soils, and streams.Forest Ecology and Management, 262, 95-104. DOI URL
[28]	Lü CQ, Tian HQ, Huang Y (2007). Ecological effects of increased nitrogen deposition in terrestrial ecosystems.Journal of Plant Ecology (Chinese Version), 31, 205-218. (in Chinese with English abstract)[吕超群, 田汉勤, 黄耀 (2007). 陆地生态系统氮沉降增加的生态效应. 植物生态学报, 31, 205-218.] DOI URL
[29]	Majdi H, Pregitzer K, Moren A, Nylund J, Gren GRIA (2005). Measuring fine root turnover in forest ecosystems.Plant and Soil, 276, 1-8. DOI URL
[30]	Mei L, Gu J, Zhang Z, Wang Z (2010). Responses of fine root mass, length, production and turnover to soil nitrogen fertilization inLarix gmelinii and Fraxinus mandshurica forests in Northeastern China. Journal of Forest Research, 15, 194-201.
[31]	Nacry P, Bouguyon E, Gojon A (2013). Nitrogen acquisition by roots: Physiological and developmental mechanisms ensuring plant adaptation to a fluctuating resource.Plant and Soil, 370, 1-29. DOI URL
[32]	Noguchi K, Nagakura J, Kaneko S (2013). Biomass and morphology of fine roots of sugi (Cryptomeria japonica) after 3 years of nitrogen fertilization. Frontiers in Plant Science, 4, 1-7.
[33]	Ostonen I, Lohmus K, Helmisaari HS, Truu J, Meel S (2007). Fine root morphological adaptations in scots pine, Norway spruce and silver birch along a latitudinal gradient in boreal forests.Tree Physiologist, 27, 1627-1634. DOI URL PMID
[34]	Poorter H, Niklas KJ, Reich PB, Oleksyn J, Poot P, Mommer L (2011). Biomass allocation to leaves, stems and roots: Meta-analyses of interspecific variation and environmental control. New Phytologist, 193, 30-50. DOI URL PMID
[35]	Shi JW, Yu SQ, Yu LZ, Han YZ, Wang ZQ, Guo DL (2006). Application of minirhizotron in fine root studies.Chinese Journal of Applied Ecology, 17, 715-719. (in Chinese with English abstract)[史建伟, 于水强, 于立忠, 韩有志, 王政权, 郭大立 (2006). 微根管在细根研究中的应用. 应用生态学报, 17, 715-719.]
[36]	Song G, Sun B, Jiao JY (2007). Comparison between ultraviolet spectrophotometry and other methods in determination of soil nitrate-N.Acta Pedologica Sinica, 44, 288-293. (in Chinese with English abstract)[宋歌, 孙波, 教剑英 (2007). 测定土壤硝态氮的紫外分光光度法与其他方法的比较. 土壤学报, 44, 288-293.] DOI URL
[37]	Tian D, Niu S (2015). A global analysis of soil acidification caused by nitrogen addition.Environmental Research Letter, 10, 1-10. DOI URL
[38]	Tingey DT, Phillips DL, Johnson MG (2003). Optimizing minirhizotron sample frequency for an evergreen and deciduous tree species.New Phytologist, 157, 155-161. DOI URL
[39]	Wang C, Han S, Zhou Y, Yan C, Cheng X, Zheng X, Li MH (2012). Responses of fine roots and soil N availability to short-term nitrogen fertilization in a broad-leaved Korean pine mixed forest in northeastern China.PLOS ONE, 7, e31042. doi: 10.1371/journal.pone.0031042. DOI URL PMID
[40]	Weemstra M, Mommer L, Visser EJW, van Ruijven J, Kuyper TW, Mohren GMJ, Sterck FJ (2016). Towards a multidimensional root trait framework: A tree root review.New Phytologist, 211, 1159-1169. DOI URL PMID
[41]	Wu YB, Che RX, Ma S, Deng YC, Zhu MJ, Cui XY (2014). Estimation of root production and turnover in an alpine meadow: Comparison of three measurement methods.Acta Ecologica Sinica, 34, 3529-3537. (in Chinese with English abstract)[吴伊波, 车荣晓, 马双, 邓永翠, 朱敏健, 崔骁勇 (2014). 高寒草甸植被细根生产和周转的比较研究. 生态学报, 34, 3529-3537.]
[42]	Wurzburger N, Wright SJ (2015). Fine root responses to fertilization reveal multiple nutrient limitation in a lowland tropical forest.Ecology, 96, 2137-2146. DOI URL PMID
[43]	Xiao HL (2001). Effects of atmospheric nitrogen deposition on forest soil acidification. Scientia Silvae Sinica, 37(4), 111-116. (in Chinese with English abstract)[肖辉林 (2001). 大气氮沉降对森林土壤酸化的影响. 林业科学, 37(4), 111-116.] DOI URL
[44]	Xu ZF, Tu LH, Hu TX (2013). Implications of greater than average increases in nitrogen deposition on the western edge of the Szechwan basin, China.Environmental Pollution, 177, 201-202. DOI URL PMID
[45]	Yu SQ, Wang ZQ, Shi JW, Yu LZ, Quan XQ (2009). Effects of nitrogen fertilization on fine root lifespan ofFraxinus mandshurica and Larixgme. Chinese Journal of Applied Ecology, 20, 2332-2338. (in Chinese with English abstract)[于水强, 王政权, 史建伟, 于立忠, 全先奎 (2009). 氮肥对水曲柳和落叶松细根寿命的影响. 应用生态学报, 20, 2332-2338.]
[46]	Yuan YD, Yang YS, Chen GS, Yang ZJ, Lin RQ, Ling H (2009). Fine root longevity of aCunninghamia lanceolata plantation estimated by minirhizotrons. Journal of Subtropical Resources and Environment, 4(2), 47-52. (in Chinese with English abstract)[袁一丁, 杨玉盛, 陈光水, 杨智杰, 林如强, 凌华 (2009). 杉木人工林细根寿命研究. 亚热带资源与环境学报, 4(2), 47-52.]
[47]	Zheng JX, Huang JX, Wang ZZ, Xiong DC, Yang ZJ, Chen GS (2012). Fine root longevity and controlling factors in aPhoebe bournei plantation. Acta Ecologica Sinica, 23, 7532-7539. (in Chinese with English abstract)[郑金兴, 黄锦学, 王珍珍, 熊德成, 杨智杰, 陈光水 (2012). 闽楠人工林细根寿命及其影响因素. 生态学报, 23, 7532-7539.]