围封对退化高寒草甸土壤微生物群落多样性及土壤化学计量特征的影响
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摘要
围封对植被处于近自然恢复状态的退化草地有一定的修复作用,开展轻度退化草地围封过程中生物与非生物因素的协同互作研究是完整地认识草地生态系统结构和功能的基础.本试验对围栏封育10年的轻度退化草地的土壤化学计量特征进行了研究,同时采用高通量基因测序技术并结合Biolog-Eco方法,调查了土壤微生物多样性和功能的变化.结果表明:轻度退化草地实施围封后,土壤铵态氮含量显著升高,全钾含量显著降低,土壤有机碳、全氮、全磷、硝态氮、速效磷和速效钾则无明显变化.高寒草甸土壤微生物碳和氮在轻度退化和围栏封育草地间差异不显著;围栏封育后草地土壤微生物碳氮比显著高于轻度退化草地.随培养时间的延长,高寒草甸不同土层土壤微生物碳代谢强度均显著升高,土壤微生物碳代谢指数在轻度退化和围栏封育草地间差异不显著.高寒草甸土壤细菌OTUs显著高于真菌,轻度退化与围栏封育草地土壤微生物相似度为27.0%～32.7%.围封后,土壤真菌子囊菌门、接合菌门和球壶菌门相对丰富度显著升高,担子菌门显著降低,土壤细菌酸杆菌门显著低于轻度退化草地.土壤真菌和细菌群落组成在不同土层间差异较大,在轻度退化和围栏封育草地间仅有表层土壤真菌群落组成表现出较大差异.土壤细菌多样性受土壤全氮和速效钾影响较大,真菌多样性受地上生物量影响较大.土壤微生物对碳源利用能力主要受土壤速效钾影响.综上,长期围封禁牧对轻度退化草地土壤养分和土壤微生物无明显影响,且会造成牧草资源浪费,适度放牧可以保持草地资源的可持续利用.
Enclosing is an effective rehabilitation measure for degraded pastures that mimics natural recovery of vegetation. To examine the interaction between biotic and abiotic in lightly degraded and enclosing grasslands is helpful for a clear understanding of the structure and function of grassland ecosystem. In this study,soil microbial community and soil stoichiometric characteristics in lightly degraded and 10-year enclosing alpine meadows were studied by high-throughput sequencing and Biolog-Eco methods. The results showed that compared with lightly degraded grassland,the concentration of soil NH4+-N in the enclosing grassland increased significantly,while total K( TK) dramatically decreased. There was no obvious variation in soil total organic carbon( TOC),total N( TN),total P( TP),NO3--N,available P( AP),available K( AK),microbial biomass C( MBC) and microbial biomass N( MBN). The soil microbial biomass C/N was significantly enhanced. The carbon metabolic capabilities of soil microbes in different soil layers of alpine meadow were obviously increased with the prolonged incubation time,but there was no significant difference between lightly degraded and enclosed meadows. The OTUs of soil bacteria was significantly higher than that of fungi in alpine meadow. The microbial similarity between lightly degraded and fencing grasslands was 27. 0%-32. 7%. Enclosing significantly increased the fungal relative richness of Ascomycota,Zygomycetes and Chytridiomycota,while simultaneously decreased the relative abundance of Basidiomycetes. Compared with lightly degraded meadow,the bacterial relative richness of Acidobacteria significantly decreased in enclosing meadow. The community composition of soil fungi and bacteria greatly varied among different soil layers. There was significant difference of fungal community composition in the upper soils between lightly degraded and enclosed grassland.The soil bacterial community diversity was greatly affected by soil TN and AK,while the fungal community diversity was significantly affected by plant aboveground biomass. Soil AK produced great influence on soil microbial carbon source utilization capacity. Generally,long-term grazing exclosure had no significant effects on soil nutrients and soil microbial community diversity of lightly degraded grassland and thus would waste the pasture resources,whereas appropriate grazing could maintain the sustainable utilization of grassland.
Enclosing is an effective rehabilitation measure for degraded pastures that mimics natural recovery of vegetation. To examine the interaction between biotic and abiotic in lightly degraded and enclosing grasslands is helpful for a clear understanding of the structure and function of grassland ecosystem. In this study,soil microbial community and soil stoichiometric characteristics in lightly degraded and 10-year enclosing alpine meadows were studied by high-throughput sequencing and Biolog-Eco methods. The results showed that compared with lightly degraded grassland,the concentration of soil NH4+-N in the enclosing grassland increased significantly,while total K( TK) dramatically decreased. There was no obvious variation in soil total organic carbon( TOC),total N( TN),total P( TP),NO3--N,available P( AP),available K( AK),microbial biomass C( MBC) and microbial biomass N( MBN). The soil microbial biomass C/N was significantly enhanced. The carbon metabolic capabilities of soil microbes in different soil layers of alpine meadow were obviously increased with the prolonged incubation time,but there was no significant difference between lightly degraded and enclosed meadows. The OTUs of soil bacteria was significantly higher than that of fungi in alpine meadow. The microbial similarity between lightly degraded and fencing grasslands was 27. 0%-32. 7%. Enclosing significantly increased the fungal relative richness of Ascomycota,Zygomycetes and Chytridiomycota,while simultaneously decreased the relative abundance of Basidiomycetes. Compared with lightly degraded meadow,the bacterial relative richness of Acidobacteria significantly decreased in enclosing meadow. The community composition of soil fungi and bacteria greatly varied among different soil layers. There was significant difference of fungal community composition in the upper soils between lightly degraded and enclosed grassland.The soil bacterial community diversity was greatly affected by soil TN and AK,while the fungal community diversity was significantly affected by plant aboveground biomass. Soil AK produced great influence on soil microbial carbon source utilization capacity. Generally,long-term grazing exclosure had no significant effects on soil nutrients and soil microbial community diversity of lightly degraded grassland and thus would waste the pasture resources,whereas appropriate grazing could maintain the sustainable utilization of grassland.
引文
[1]Luo J-F(罗久富),Zhou J-X(周金星),Zhao W-X(赵文霞),et al.Effect of fences on functional groups and stability of the alpine meadow plant community in the Qinghai-Tibet Plateau.Pratacultural Science(草业科学),2017,34(3):565-574(in Chinese)
[2]Niu Y-J(牛钰杰),Yang S-W(杨思维),Wang G-Z(王贵珍),et al.Evaluation and selection of species diversity index under grazing disturbance in alpine meadow.Chinese Journal of Applied Ecology(应用生态学报),2017,28(6):1824-1832(in Chinese)
[3]Yin Y-L(尹亚丽),Wang Y-Q(王玉琴),Bao G-S(鲍根生),et al.Characteristics of soil microbes and enzyme activities in different degraded alpine meadows.Chinese Journal of Applied Ecology(应用生态学报),2017,28(12):3881-3890(in Chinese)
[4]Li M-J(李美君).Effects of Enclosure on the Dynamics of Grassland Communities.Master Thesis.Beijing:Beijing Forestry University,2016(in Chinese)
[5]Li Y-K(李以康),Zhang F-W(张法伟),Lin L(林丽),et al.Spatiotemporal variation in soil nutrient of Stipapurpurea steppe fenced in the Qinghai Lake region.Chinese Journal of Applied&Environmental Biology(应用与环境生物学报),2012,18(1):23-29(in Chinese)
[6]Millard P,Singh BK.Does grassland vegetation drive soil microbial diversity?Nutrient Cycling in Agroecosystems,2010,88:147-158
[7]Yang YS,Li HQ,Zhang L,et al.Characteristics of soil water percolation and dissolved organic carbon leaching and their response to long-term fencing in an alpine meadow on the Tibetan Plateau.Environmental Earth Sciences,2016,75(23):1471,doi:10.1007/s12665-016-6178-0
[8]Yang YF,Wu LW,Lin QY,et al.Responses of the functional structure of soil microbial community to livestock grazing in the Tibetan alpine grassland.Global Change Biology,2013,19:637-648
[9]Fu G(付刚),Shen Z-X(沈振西).Grazing alters soil microbial community in alpine grasslands of northern Tibet.Acta Prataculturae Sinica(草业学报),2017,26(10):170-178(in Chinese)
[10]McGuire KL,Zak DR,Edwards IP,et al.Slowed decomposition is biotically mediated in an ectomycorrhizal,tropical rain forest.Oecologia,2010,164:785-795
[11]Niu L(牛磊),Liu Y-H(刘颖慧),Li Y(李悦),et al.Microbial community structure of the alpine meadow under different grazing styles in Naqu prefecture of Tibet.Chinese Journal of Applied Ecology(应用生态学报),2015,26(8):2298-2306(in Chinese)
[12]Royertardif S,Bradley RL,Parsons WFJ.Evidence that plant diversity and site productivity confer stability to forest floor microbial biomass.Soil Biology&Biochemistry,2010,42:813-821
[13]Cao C-Y(曹成有),Yao J-D(姚金冬),Han X-S(韩晓姝),et al.Soil microbes functional diversity in sandfixing Caragana microphylla communities in Horqin Sandy Land.Chinese Journal of Applied Ecology(应用生态学报),2011,22(9):2309-2315(in Chinese)
[14]Li YM,Wang SP,Jiang LL,et al.Changes of soil microbial community under different degraded gradients of alpine meadow.Agriculture,Ecosystems and Environment,2016,222:213-222
[15]Gao F(高凤),Wang B(王斌),Shi Y-X(石玉祥),et al.The response of alpine grasslands ecosystem in the north Tibet to short-term enclosure.Acta Ecologica Sinica(生态学报),2017,37(13):4366-4374(in Chinese)
[16]Si G-C(斯贵才),Yuan Y-L(袁艳丽),Wang J(王建),et al.Effects of fencing on microbial communities and soil enzyme activities in Damxung alpine grassland.Pratacultural Science(草业科学),2015,32(1):1-10(in Chinese)
[17]Ma Y-S(马玉寿),Lang B-N(郎百宁),Li Q-Y(李青云),et al.Study on rehabilitating and rebuilding technologies for degenerated alpine meadow in the Changjiang and Yellow river source region.Pratacultural Science(草业科学),2002,19(9):1-4(in Chinese)
[18]Li Y-N(李英年).Simulation of forage yield and stocking rate on alpine grassland in response to warming trend of climate.Acta Prataculturae Sinica(草业学报),2000,9(2):77-82(in Chinese)
[19]Ren J-Z(任继周).Research Methods of Pratacultural Science.Beijing:China Agriculture Press,1998(in Chinese)
[20]Yang J-H(杨剑虹).Soil Agrochemical Analysis and Environmental Monitoring.Beijing:China Land Press,2008(in Chinese)
[21]Lin X-G(林先贵).Principles and Methods of Soil Microbial Research.Beijing:Higher Education Press,2010(in Chinese)
[22]Dang W(党雯),Gao C-H(郜春花),Zhang Q(张强),et al.Screening of preprocessing methods of biolog for soil microbial community functional diversity.Chinese Agricultural Science Bulletin(中国农学通报),2015,31(2):153-158(in Chinese)
[23]Wang Z-C(汪珍川).The Effects of Rice Straw Addition Amount on Physicalochemical Parameters and Microbial Community of Swine Manure Composting.Master Thesis.Changsha:Hunan Agricultural University,2015(in Chinese)
[24]Song Y-L(宋云龙),Zhang J-S(张金松),Zhu J(朱佳),et al.Analysis of microbial community in in-situ sludge reduction process by bioaugmentation using highthroughput sequencing technology.China Environmental Science(中国环境科学),2016,36(7):2099-2107(in Chinese)
[25]Reeder JD,Schuman GE.Influence of livestock grazing on C sequestration in semi-arid mixed-grass and shortgrass rangelands.Environmental Pollution,2002,116:457-463
[26]Dan Z-T-Q(旦增塔庆),Bai M-G-W(白玛嘎翁),Duo J-D-Z(多吉顿珠),et al.Effects of livestock exclusion duration years on plant and soil properties in a Tibetan alpine meadow.Pratacultural Science(草业科学),2018,35(1):10-17(in Chinese)
[27]Zhang J-P(张建鹏),Li Y-Q(李玉强),Zhao X-Y(赵学勇),et al.Effects of exclosure on soil physicochemical properties and carbon sequestration potential recovery of desertified grassland.Journal of Desert Research(中国沙漠),2017,37(3):491-499(in Chinese)
[28]Wang Y-F(王艳芬),Chen Z-Z(陈佐忠).Distribution of soil organic carbon in the major grasslands of Xilingguole,Inner Monogolia,China.Acta Phytoecologica Sinica(植物生态学报),1998,22(6):545-551(in Chinese)
[29]Elliott ET,Valentine DW,Williams SA.Carbon and nitrogen dynamics in elk winter ranges.Journal of Range Management,2001,54:400-408
[30]An H,Li GQ.Effects of grazing on carbon and nitrogen in plants and soils in a semiarid desert grassland,China.Journal of Arid Land,2015,7:341-349
[31]Milchunas DG,Lauenroth WK.Quantitative effects of grazing on vegetation and soils over a global range of environments.Ecological Monographs,1993,63:327-366
[32]Niu D-C(牛得草),Jiang S-G(江世高),Qin Y(秦燕),et al.Effects of grazing and fencing on soil microorganisms and enzymes activities.Pratacultural Science(草业科学),2013,30(4):528-534(in Chinese)
[33]Li Q,Mayzlish E,Shamir I,et al.Impact of grazing on soil biota in Mediterranean grassland.Land Degradation&Development,2005,16:581-592
[34]Qi S,Zheng H,Lin Q,et al.Effects of livestock grazing intensity on soil biota in a semiarid steppe of Inner Mongolia.Plant and Soil,2011,340:117-126
[35]Lin B,Zhao X,Zheng Y,et al.Effect of grazing intensity on protozoan community,microbial biomass,and enzyme activity in an alpine meadow on the Tibetan Plateau.Journal of Soils and Sediments,2017,17:1-11
[36]Rui YC,Wang SP,Xu ZH,et al.Warming and grazing affect soil labile carbon and nitrogen pools differently in an alpine meadow of the Qinghai-Tibet Plateau in China.Journal of Soils and Sediments,2011,11:903-914
[37]Wu GL,Liu ZH,Zhang L,et al.Long-term fencing improved soil properties and soil organic carbon storage in an alpine swamp meadow of western China.Plant and Soil,2010,332:331-337
[38]Tian C-J(田春杰),Chen J-K(陈家宽),Zhong Y(钟扬).Phylogenic diversity of microbes and its perspectives in conservation biology.Chinese Journal of Applied Ecology(应用生态学报),2003,14(4):609-612(in Chinese)
[39]Zhang W,Wu XK,Liu GX,et al.Tag-encoded pyrosequencing analysis of bacterial diversity within different alpine grassland ecosystems of the Qinghai-Tibet Plateau,China.Environmental Earth Sciences,2014,72:779-786
[40]Wang MM,Wang SP,Wu LW,et al.Evaluating the lingering effect of livestock grazing on functional potentials of microbial communities in Tibetan grassland soils.Plant and Soil,2016,407:385-399
[2]Niu Y-J(牛钰杰),Yang S-W(杨思维),Wang G-Z(王贵珍),et al.Evaluation and selection of species diversity index under grazing disturbance in alpine meadow.Chinese Journal of Applied Ecology(应用生态学报),2017,28(6):1824-1832(in Chinese)
[3]Yin Y-L(尹亚丽),Wang Y-Q(王玉琴),Bao G-S(鲍根生),et al.Characteristics of soil microbes and enzyme activities in different degraded alpine meadows.Chinese Journal of Applied Ecology(应用生态学报),2017,28(12):3881-3890(in Chinese)
[4]Li M-J(李美君).Effects of Enclosure on the Dynamics of Grassland Communities.Master Thesis.Beijing:Beijing Forestry University,2016(in Chinese)
[5]Li Y-K(李以康),Zhang F-W(张法伟),Lin L(林丽),et al.Spatiotemporal variation in soil nutrient of Stipapurpurea steppe fenced in the Qinghai Lake region.Chinese Journal of Applied&Environmental Biology(应用与环境生物学报),2012,18(1):23-29(in Chinese)
[6]Millard P,Singh BK.Does grassland vegetation drive soil microbial diversity?Nutrient Cycling in Agroecosystems,2010,88:147-158
[7]Yang YS,Li HQ,Zhang L,et al.Characteristics of soil water percolation and dissolved organic carbon leaching and their response to long-term fencing in an alpine meadow on the Tibetan Plateau.Environmental Earth Sciences,2016,75(23):1471,doi:10.1007/s12665-016-6178-0
[8]Yang YF,Wu LW,Lin QY,et al.Responses of the functional structure of soil microbial community to livestock grazing in the Tibetan alpine grassland.Global Change Biology,2013,19:637-648
[9]Fu G(付刚),Shen Z-X(沈振西).Grazing alters soil microbial community in alpine grasslands of northern Tibet.Acta Prataculturae Sinica(草业学报),2017,26(10):170-178(in Chinese)
[10]McGuire KL,Zak DR,Edwards IP,et al.Slowed decomposition is biotically mediated in an ectomycorrhizal,tropical rain forest.Oecologia,2010,164:785-795
[11]Niu L(牛磊),Liu Y-H(刘颖慧),Li Y(李悦),et al.Microbial community structure of the alpine meadow under different grazing styles in Naqu prefecture of Tibet.Chinese Journal of Applied Ecology(应用生态学报),2015,26(8):2298-2306(in Chinese)
[12]Royertardif S,Bradley RL,Parsons WFJ.Evidence that plant diversity and site productivity confer stability to forest floor microbial biomass.Soil Biology&Biochemistry,2010,42:813-821
[13]Cao C-Y(曹成有),Yao J-D(姚金冬),Han X-S(韩晓姝),et al.Soil microbes functional diversity in sandfixing Caragana microphylla communities in Horqin Sandy Land.Chinese Journal of Applied Ecology(应用生态学报),2011,22(9):2309-2315(in Chinese)
[14]Li YM,Wang SP,Jiang LL,et al.Changes of soil microbial community under different degraded gradients of alpine meadow.Agriculture,Ecosystems and Environment,2016,222:213-222
[15]Gao F(高凤),Wang B(王斌),Shi Y-X(石玉祥),et al.The response of alpine grasslands ecosystem in the north Tibet to short-term enclosure.Acta Ecologica Sinica(生态学报),2017,37(13):4366-4374(in Chinese)
[16]Si G-C(斯贵才),Yuan Y-L(袁艳丽),Wang J(王建),et al.Effects of fencing on microbial communities and soil enzyme activities in Damxung alpine grassland.Pratacultural Science(草业科学),2015,32(1):1-10(in Chinese)
[17]Ma Y-S(马玉寿),Lang B-N(郎百宁),Li Q-Y(李青云),et al.Study on rehabilitating and rebuilding technologies for degenerated alpine meadow in the Changjiang and Yellow river source region.Pratacultural Science(草业科学),2002,19(9):1-4(in Chinese)
[18]Li Y-N(李英年).Simulation of forage yield and stocking rate on alpine grassland in response to warming trend of climate.Acta Prataculturae Sinica(草业学报),2000,9(2):77-82(in Chinese)
[19]Ren J-Z(任继周).Research Methods of Pratacultural Science.Beijing:China Agriculture Press,1998(in Chinese)
[20]Yang J-H(杨剑虹).Soil Agrochemical Analysis and Environmental Monitoring.Beijing:China Land Press,2008(in Chinese)
[21]Lin X-G(林先贵).Principles and Methods of Soil Microbial Research.Beijing:Higher Education Press,2010(in Chinese)
[22]Dang W(党雯),Gao C-H(郜春花),Zhang Q(张强),et al.Screening of preprocessing methods of biolog for soil microbial community functional diversity.Chinese Agricultural Science Bulletin(中国农学通报),2015,31(2):153-158(in Chinese)
[23]Wang Z-C(汪珍川).The Effects of Rice Straw Addition Amount on Physicalochemical Parameters and Microbial Community of Swine Manure Composting.Master Thesis.Changsha:Hunan Agricultural University,2015(in Chinese)
[24]Song Y-L(宋云龙),Zhang J-S(张金松),Zhu J(朱佳),et al.Analysis of microbial community in in-situ sludge reduction process by bioaugmentation using highthroughput sequencing technology.China Environmental Science(中国环境科学),2016,36(7):2099-2107(in Chinese)
[25]Reeder JD,Schuman GE.Influence of livestock grazing on C sequestration in semi-arid mixed-grass and shortgrass rangelands.Environmental Pollution,2002,116:457-463
[26]Dan Z-T-Q(旦增塔庆),Bai M-G-W(白玛嘎翁),Duo J-D-Z(多吉顿珠),et al.Effects of livestock exclusion duration years on plant and soil properties in a Tibetan alpine meadow.Pratacultural Science(草业科学),2018,35(1):10-17(in Chinese)
[27]Zhang J-P(张建鹏),Li Y-Q(李玉强),Zhao X-Y(赵学勇),et al.Effects of exclosure on soil physicochemical properties and carbon sequestration potential recovery of desertified grassland.Journal of Desert Research(中国沙漠),2017,37(3):491-499(in Chinese)
[28]Wang Y-F(王艳芬),Chen Z-Z(陈佐忠).Distribution of soil organic carbon in the major grasslands of Xilingguole,Inner Monogolia,China.Acta Phytoecologica Sinica(植物生态学报),1998,22(6):545-551(in Chinese)
[29]Elliott ET,Valentine DW,Williams SA.Carbon and nitrogen dynamics in elk winter ranges.Journal of Range Management,2001,54:400-408
[30]An H,Li GQ.Effects of grazing on carbon and nitrogen in plants and soils in a semiarid desert grassland,China.Journal of Arid Land,2015,7:341-349
[31]Milchunas DG,Lauenroth WK.Quantitative effects of grazing on vegetation and soils over a global range of environments.Ecological Monographs,1993,63:327-366
[32]Niu D-C(牛得草),Jiang S-G(江世高),Qin Y(秦燕),et al.Effects of grazing and fencing on soil microorganisms and enzymes activities.Pratacultural Science(草业科学),2013,30(4):528-534(in Chinese)
[33]Li Q,Mayzlish E,Shamir I,et al.Impact of grazing on soil biota in Mediterranean grassland.Land Degradation&Development,2005,16:581-592
[34]Qi S,Zheng H,Lin Q,et al.Effects of livestock grazing intensity on soil biota in a semiarid steppe of Inner Mongolia.Plant and Soil,2011,340:117-126
[35]Lin B,Zhao X,Zheng Y,et al.Effect of grazing intensity on protozoan community,microbial biomass,and enzyme activity in an alpine meadow on the Tibetan Plateau.Journal of Soils and Sediments,2017,17:1-11
[36]Rui YC,Wang SP,Xu ZH,et al.Warming and grazing affect soil labile carbon and nitrogen pools differently in an alpine meadow of the Qinghai-Tibet Plateau in China.Journal of Soils and Sediments,2011,11:903-914
[37]Wu GL,Liu ZH,Zhang L,et al.Long-term fencing improved soil properties and soil organic carbon storage in an alpine swamp meadow of western China.Plant and Soil,2010,332:331-337
[38]Tian C-J(田春杰),Chen J-K(陈家宽),Zhong Y(钟扬).Phylogenic diversity of microbes and its perspectives in conservation biology.Chinese Journal of Applied Ecology(应用生态学报),2003,14(4):609-612(in Chinese)
[39]Zhang W,Wu XK,Liu GX,et al.Tag-encoded pyrosequencing analysis of bacterial diversity within different alpine grassland ecosystems of the Qinghai-Tibet Plateau,China.Environmental Earth Sciences,2014,72:779-786
[40]Wang MM,Wang SP,Wu LW,et al.Evaluating the lingering effect of livestock grazing on functional potentials of microbial communities in Tibetan grassland soils.Plant and Soil,2016,407:385-399