长期施肥和增水对半干旱草地土壤性质和植物性状的影响
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摘要
本文对内蒙古多伦退化草地2005年建立的长期野外控制试验中施肥和增水对土壤性质和植物群落特征的影响进行了总结和综合评述.结果表明:加氮导致了表土酸化并降低酸缓冲容量,提高了表土中碳氮磷硫有效性及DTPA-浸提态铁锰铜含量,导致盐基离子钙镁钾钠总量的消耗,降低了土壤微生物群落多样性,促进了优势植物物种叶片对氮磷硫钾及锰铜锌的吸收,抑制植物叶片对铁的吸收,而对钙镁吸收无显著影响,增加了植物地上净初级生产力(ANPP),降低了植物物种多样性和群落稳定性.单独加磷增加了表土全磷和Olsen-P含量及真菌丰度,促进了植物叶片对氮、磷、硫的吸收,但对其他土壤基本化学性质及ANPP、物种多样性无显著影响.增水提高了植物群落对干旱的抵抗力,但对ANPP增长的贡献受到土壤氮有效性的限制.增水对于加氮导致的土壤酸化、植物和微生物多样性降低等具有一定的缓冲作用;加氮增水和加磷增水下,土壤微生物多样性及功能受地上植物群落结构及功能变化的影响.长期野外控制试验对于深入理解草地生态系统结构和功能对环境变化的响应具有重要意义,但单点的研究结果仍需与不同区域多点控制试验的联网研究相结合,深入开展地上与地下生态过程的关联研究,才能深入理解草地生态系统生态学的相关机制.
We summarized the effects of fertilization and water addition on some soil properties and plant community characteristics in a long-term field experiment established in 2005 in a degraded grassland in Duolun, Inner Mongolia, China. The results showed that nitrogen(N) addition resulted in surface soil acidification and decreased acid buffering capacity, increased the availability of carbon(C), N, phosphorus(P), sulfur(S) and DTPA-extractable iron(Fe), manganese(Mn), and copper(Cu) contents, depleted the sum of base cations calcium(Ca), magnesium(Mg), potassium(K) and sodium(Na), decreased the diversity of soil microbial community. Nitrogen addition enhanced the uptake of N, P, S, K, Mn, Cu and Zn by plants, while inhibited plant Fe uptake, but with no effect on the uptake of Ca or Mg. Nitrogen addition increased aboveground net primary productivity(ANPP) but declined plant species diversity and community stability. Phosphorus addition alone increased total P and Olsen-P contents and fungal abundance in the surface soil, and improved N, P and S uptake by leaves, but had no significant influence on other soil basic chemical properties, ANPP, and plant species diversity. Water addition could improve the resistance of plant community, but its contribution to ANPP was limited by soil N availa-bility. Water addition could buffer soil acidification and the decline of microbial and plant diversity induced by N addition. Under the treatments of N and water addition or P and water addition, the diversity and function of soil microorganisms were affected by plant community structure and function. Long-term controlled field experiments were useful for understanding ecosystem structure and functions of grasslands. However, to uncover the underlying mechanisms in grassland ecosystem ecology, single-site experiments should be incorporated with multiple-site controlled field experiments in different regions. More attentions should be paid to the linkage of above-and below-ground ecological processes.
We summarized the effects of fertilization and water addition on some soil properties and plant community characteristics in a long-term field experiment established in 2005 in a degraded grassland in Duolun, Inner Mongolia, China. The results showed that nitrogen(N) addition resulted in surface soil acidification and decreased acid buffering capacity, increased the availability of carbon(C), N, phosphorus(P), sulfur(S) and DTPA-extractable iron(Fe), manganese(Mn), and copper(Cu) contents, depleted the sum of base cations calcium(Ca), magnesium(Mg), potassium(K) and sodium(Na), decreased the diversity of soil microbial community. Nitrogen addition enhanced the uptake of N, P, S, K, Mn, Cu and Zn by plants, while inhibited plant Fe uptake, but with no effect on the uptake of Ca or Mg. Nitrogen addition increased aboveground net primary productivity(ANPP) but declined plant species diversity and community stability. Phosphorus addition alone increased total P and Olsen-P contents and fungal abundance in the surface soil, and improved N, P and S uptake by leaves, but had no significant influence on other soil basic chemical properties, ANPP, and plant species diversity. Water addition could improve the resistance of plant community, but its contribution to ANPP was limited by soil N availa-bility. Water addition could buffer soil acidification and the decline of microbial and plant diversity induced by N addition. Under the treatments of N and water addition or P and water addition, the diversity and function of soil microorganisms were affected by plant community structure and function. Long-term controlled field experiments were useful for understanding ecosystem structure and functions of grasslands. However, to uncover the underlying mechanisms in grassland ecosystem ecology, single-site experiments should be incorporated with multiple-site controlled field experiments in different regions. More attentions should be paid to the linkage of above-and below-ground ecological processes.
引文
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[3] Kang L,Han XG,Zhang ZB,et al.Grassland ecosystems in China:Review of current knowledge and research advancement.Philosophical Transactions of the Royal Society of London B:Biological Sciences,2007,362:997-1008
[4] Yu Z-L (于振良).Ecology:Current Knowledge and Future Challenges.Beijing:Higher Education Press,2017 (in Chinese)
[5] Xu Z-W (徐柱文).Effects of Water and Fertilizer Addition on Community Structure and Stability of Diffe-rent Land-use History Grassland in an Agro-pastoral Ecotone in Inner Mongolia.PhD Thesis.Beijing:Graduate School of Chinese Academy of Sciences,2009 (in Chinese)
[6] Wei J-M (魏金明).Impacts of Water and Fertilizer Addition on Soil Characteristics in Temperate Grasslands.Master Thesis.Beijing:Graduate School of Chinese Academy of Sciences,2011 (in Chinese)
[7] Wei J-M (魏金明),Jiang Y (姜勇),Fu M-M (符明明),et al.Effects of water addition and fertilization on soil nutrient contents and pH value of typical grassland in Inner Mongolia.Chinese Journal of Ecology (生态学杂志),2011,30(8):1642-1646 (in Chinese)
[8] Yang S (杨山).Precipitation and Fertilizers Influence of Soil Microbiological Characteristics in Inner Mongolia Typical Steppe.Master Thesis.Shenyang:Shenyang University,2014 (in Chinese)
[9] Cai J-P (蔡江平).Effects of Nitrogen and Water Addition on Soil Acid Buffering Capacity and Plant Mineral Elements Uptake in a Semi-arid Grassland.PhD Thesis.Beijing:University of Chinese Academy of Sciences,2017 (in Chinese)
[10] Cai JP,Luo WT,Liu HY,et al.Precipitation-mediated responses of soil acid buffering capacity to long-term nitrogen addition in a semi-arid grassland.Atmospheric Environment,2017,170:312-318
[11] Wang R-Z (王汝振).Effect of Nitrogen and Water Addition on Soil Aggregate Elements and Enzyme Activities in a Semi-arid Grassland of Northern China.PhD Thesis.Beijing:University of Chinese Academy of Sciences,2015 (in Chinese)
[12] Wang RZ,Dungait JAJ,Buss HL,et al.Base cations and micronutrients in soil aggregates as affected by enhanced nitrogen and water inputs in a semi-arid steppe grassland.Science of the Total Environment,2017,575:564-572
[13] Yang YH,Ji CJ,Ma WH,et al.Significant soil acidification across northern China’s grasslands during 1980s-2000s.Global Change Biology,2012,18:2292-2300
[14] Wang RZ,Dungait JAJ,Creamer CA,et al.Carbon and nitrogen dynamics in soil aggregates under long-term nitrogen and water addition in a temperate steppe.Soil Science Society of America Journal,2015,79:527-535
[15] Wang RZ,Creamer CA,Wang X,et al.The effects of a 9-year nitrogen and water addition on soil aggregate phosphorus and sulfur availability in a semi-arid grassland.Ecological Indicators,2016,61:806-814
[16] Yin JF,Wang RZ,Liu HY,et al.Nitrogen addition alters elemental stoichiometry within soil aggregates in a temperate steppe.Solid Earth,2016,7:1565-1575
[17] Lu M,Zhou XH,Luo YQ,et al.Minor stimulation of soil carbon storage by nitrogen addition:A meta-analysis.Agriculture,Ecosystems and Environment,2011,140:234-244
[18] Lu M,Yang YH,Luo YQ,et al.Responses of ecosystem nitrogen cycle to nitrogen addition:A meta-analysis.New Photologist,2011,289:1040-1050
[19] Yang YH,Fang JY,Ji CJ,et al.Stoichiometric shifts in surface soils over broad geographical scales:Evidence from China’s grasslands.Global Ecology and Biogeography,2014,23:947-955
[20] Yang S,Xu ZW,Wang RZ,et al.Variations in soil microbial community composition and enzymatic activities in response to increased N deposition and precipitation in Inner Mongolian grassland.Applied Soil Ecology,2017,119:275-285
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[24] Wang RZ,Dijkstra FA,Liu HY,et al.Response of soil carbon to nitrogen and water addition differs between labile and recalcitrant fractions:Evidence from multi-year data and different soil depths in a semi-arid steppe.Catena,2019,172:857-865
[25] Wang RZ,Dorodnikov M,Dijkstra FA,et al.Sensitivities to nitrogen and water addition vary among microbial groups within soil aggregates in a semiarid grassland.Biology and Fertility of Soils,2017,53:129-140
[26] Li H,Xu ZW,Yang S,et al.Responses of soil bacterial communities to nitrogen deposition and precipitation increment are closely linked with aboveground community variation.Microbial Ecology,2016,71:974-989
[27] Chen Y-L (陈永亮).Responses of Ammonia Oxidizers and AM Fungi to Environmental Changes in a Typical Temperate Steppe.PhD Thesis.Beijing:University of Chinese Academy of Sciences,2014 (in Chinese)
[28] Chen YL,Xu ZW,Hu HW,et al.Responses of ammonia-oxidizing bacteria and archaea to nitrogen fertilization and precipitation increment in a typical temperate steppe in Inner Mongolia.Applied Soil Ecology,2013,68:36-45
[29] Chen YL,Xu ZW,Xu TL,et al.Nitrogen deposition and precipitation induced phylogenetic clustering of arbuscular mycorrhizal fungal communities.Soil Biology & Biochemistry,2017,115:233-242
[30] Li H,Yang S,Xu ZW,et al.Responses of soil microbial functional genes to global changes are indirectly influenced by aboveground plant biomass variation.Soil Bio-logy & Biochemistry,2017,104:18-29
[31] Fierer N,Lauber CL,Ramirez KS,et al.Comparative metagenomic,phylogenetic and physiological analyses of soil microbial communities across nitrogen gradients.ISME Journal,2012,6:1007-1017
[32] Lauber CL,Strickland MS,Bradford MA,et al.The influence of soil properties on the structure of bacterial and fungal communities across land-use types.Soil Bio-logy & Biochemistry,2008,40:2407-2415
[33] Johnson NC,Rowland DL,Corkidi L,et al.Nitrogen enrichment alters mycorrhizal allocation at five mesic to semiarid grasslands.Ecology,2003,84:1895-1908
[34] Cruz-Martinez K,Suttle KB,Brodie EL,et al.Despite strong seasonal responses,soil microbial consortia are more resilient to long-term changes in rainfall than overlying grassland.ISME Journal,2009,3:738-744
[35] Ren HY,Xu ZW,Isbell F,et al.Exacerbated nitrogen limitation ends transient stimulation of grassland productivity by increased precipitation.Ecological Monographs,2017,87:457-469
[36] Xu ZW,Li MH,Zimmermann N,et al.Plant functional diversity modulates global environmental change effects on grassland productivity.Journal of Ecology,2018,106:1941-1951
[37] Ren H-Y (任海燕).Effects and Mechanisms of Nitrogen and Water Addition on Leaf Longevity in a Tempe-rate Typical Steppe.PhD Thesis.Beijing:Graduate School of Chinese Academy of Sciences,2011 (in Chinese)
[38] Ren HY,Xu ZW,Huang JH,et al.Nitrogen and water addition reduce leaf longevity of steppe species.Annals of Botany,2011,107:145-155
[39] Ren HY,Xu ZW,Zhang WH,et al.Linking ethylene to nitrogen-dependent leaf longevity of grass species in a temperate steppe.Annals of Botany,2013,112:1879-1885
[40] Ren HY,Xu ZW,Huang JH,et al.Increased precipitation induces a positive plant-soil feedback in a semi-arid grassland.Plant and Soil,2015,389:211-223
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