This study proposed an integrated biogeochemical modeling of nitrogen load from anthropogenic and natural sources in Japan.Firstly,the nitrogen load(NL) from different sources such as crop,livestock,industrial plant,u...This study proposed an integrated biogeochemical modeling of nitrogen load from anthropogenic and natural sources in Japan.Firstly,the nitrogen load(NL) from different sources such as crop,livestock,industrial plant,urban and rural resident was calculated by using datasets of fertilizer utilization,population distribution, land use map,and social census.Then,the nitrate leaching from soil layers in farmland,grassland and natural conditions was calculated by using a展开更多
To protect important resources under their bureau’s purview, the United States National Park Service’s (NPS) Arctic Network (ARCN) has developed a series of “vital signs” that are to be periodically monitored. One...To protect important resources under their bureau’s purview, the United States National Park Service’s (NPS) Arctic Network (ARCN) has developed a series of “vital signs” that are to be periodically monitored. One of these vital signs focuses on wet and dry deposition of atmospheric chemicals and further, the establishment of critical load (CL) values (thresholds for ecological effects based on cumulative depositional loadings) for nitrogen (N), sulfur, and metals. As part of the ARCN terrestrial monitoring programs, samples of the feather moss Hylocomium splendens are being collected and analyzed as a cost-effective means to monitor atmospheric pollutant deposition in this region. Ultimately, moss data combined with refined CL values might be used to help guide future regulation of atmospheric contaminant sources potentially impacting Arctic Alaska. But first, additional long-term studies are needed to determine patterns of contaminant deposition as measured by moss biomonitors and to quantify ecosystem responses at particular loadings/ ranges of contaminants within Arctic Alaska. Herein we briefly summarize 1) current regulatory guidance related to CL values 2) derivation of CL models for N and metals, 3) use of mosses as biomonitors of atmospheric deposition and loadings, 4) preliminary analysis of vulnerabilities and risks associated with CL estimates for N, 5) preliminary analysis of existing data for characterization of CL values for N for interior Alaska and 6) implications for managers and future research needs.展开更多
To evaluate the nitrogen pollution load in an aquifer, a water and nitrogen balance analysis was conducted over a thirty-five year period at five yearly intervals. First, we established a two-horizon model comprising ...To evaluate the nitrogen pollution load in an aquifer, a water and nitrogen balance analysis was conducted over a thirty-five year period at five yearly intervals. First, we established a two-horizon model comprising a channel/soil horizon, and an aquifer horizon, with exchange of water between the aquifer and river. The nitrogen balance was estimated from the product of nitrogen concentration and water flow obtained from the water balance analysis. The aquifer nitrogen balance results were as follows: 1) In the aquifer horizon, the total nitrogen pollution load potential (NPLP) peaked in the period 1981-1990 at 1800 t·yr-1;following this the NPLP rapidly decreased to about 600 t·yr-1 in the period 2006-2010. The largest NPLP input component of 1000 t·yr-1 in the period 1976-1990 was from farmland. Subsequently, farmland NPLP decreased to only 400 t·yr-1 between 2006 and 2010. The second largest input component, 600 t·yr-1, was effluent from wastewater treatment works (WWTWs) in the period 1986-1990;this also decreased markedly to about 100 t·yr-1 between 2006 and 2010;2) The difference between input and output in the aquifer horizon, used as an index of groundwater pollution, peaked in the period 1986-1990 at about 1200 t·yr-1. This gradually decreased to about 200 t·yr-1 by 2006-2010. 3) The temporal change in NPLP coincided with the nitrogen concentration of the rivers in the study area. In addition, nitrogen concentrations in two test wells were 1.0 mg·l-1 at a depth of 150 m and only 0.25 mg·l-1 at 50 m, suggesting gradual percolation of the nitrogen polluted water deeper in the aquifer.展开更多
With the control of point source pollution in Dianchi Lake basin, and the expansion of Kunming city, non-point source pollution has become the main source pollution of urban water environment and Dianchi Lake. To reve...With the control of point source pollution in Dianchi Lake basin, and the expansion of Kunming city, non-point source pollution has become the main source pollution of urban water environment and Dianchi Lake. To reveal the nitrogen pollution characteristics in watershed, this research selected key monitoring points and sections at Baoxiang river basin in rainy season which is the peak transported time of non-point source pollution, the nitrogen and hydrological indicators are monitored systematically. The different forms of nitrogen are analyzed, the pollution load of nitrogen are calculated and studied at cardinal sections; combined with the literature data, we compared the water nitrogen characteristics of Dianchi basin and Taihu basin, the main results are as follows:(1) In summer, water nitrogen form of Baoxiang river in the Caohe area is dominated by nitrate nitrogen, while in other areas it is dominated by ammonia nitrogen which is accounted for 31%-50% of total nitrogen;(2) The water pollution loads of Baoxiang river tended to increase from upstream to downstream, from June to August the total nitrogen pollution mainly comes from urban areas and the pollution load is 166.408 t;(3) In Dianchi Lake watershed and Taihu Lake watershed nitrogen concentration of inflow river is higher than that of the lake, nitrate nitrogen concentration between inflow river and lake shows a little difference, while ammonia nitrogen concentration of inflow river is higher than that of the lake. The results can provide the theoretical basis for nonpoint source pollution control and urban water environment planning and improvement in Dianchi Lake Basin.展开更多
This study of Mikasa City in 2001, which analyzed N flow between N production and N load in seven agricultural and settlement subsystems, i.e., paddy, onion, wheat, vegetable, dairy, chicken, and citizen subsystems, a...This study of Mikasa City in 2001, which analyzed N flow between N production and N load in seven agricultural and settlement subsystems, i.e., paddy, onion, wheat, vegetable, dairy, chicken, and citizen subsystems, aimed to compare N flow in each subsystem, to determine the main sources of the N load, and to evaluate the influence of agricultural production and food consumption on N cycling in a rural area. The results showed that in Mikasa city, 38.5% of the N load came from point sources and the remainder from non-point sources with intensive vegetable farming imparting a serious N load. Because of the internal N cycling in the dairy subsystem, chemical fertilizer application was reduced by 70.2%, and 23.72 Mg manure N was recycled to the field; therefore, the N utilization efficiency was raised from 18.1% to 35.1%. If all the manure N in the chicken subsystem was recycled, chemical fertilizer application would be reduced by 8.1% from the present level, and the point sources of N pollution would be reduced by 20.8%.展开更多
Baseflow is one of the major pathways of runoff in hilly areas,and its contributions to surface water resources and pollutant loads cannot be ignored.In this study,based on water quantity and quality data from 1988 to...Baseflow is one of the major pathways of runoff in hilly areas,and its contributions to surface water resources and pollutant loads cannot be ignored.In this study,based on water quantity and quality data from 1988 to 2019 in hilly and low rainfall watersheds,we focused on the impact of long-term baseflow on nitrogen load using the load allocation based on the baseflow separation method.We also constructed a nitrogen balance model for the Chaohe River Basin of China from 2012 to 2021 to analyze the nitrogen accumulation in the basin.We used the baseflow nitrogen load lag analysis method to study the lag characteristics of the baseflow discharge process and analyzed the response and periodicity of baseflow nitrogen to precipitation and soil accumulation using time delay analysis.The res-ults showed that the contribution rate of baseflow nitrogen reached 69%and showed a slight increasing trend from 1988 to 2019.The ef-fects of changes in precipitation and nitrogen accumulation on the baseflow contribution was observed after 1-2 and 2 yr,respectively.After nitrogen accumulation,it entered the river channel through baseflow,which was already the main and continuous source of nitro-gen in rivers in hilly areas.展开更多
An experiment was carried out to investigate the anti-ammonium shock load capacity of a biological aerated filter （BAF） composed of a double-layer bed. This bed was made up of a top layer of ceramic and a bottom lay...An experiment was carried out to investigate the anti-ammonium shock load capacity of a biological aerated filter （BAF） composed of a double-layer bed. This bed was made up of a top layer of ceramic and a bottom layer of zeolite. The experiment shows that the anti-ammonium shock load process can be divided into two processes： adsorption and release. In the adsorption process, the total removal efficiency of ammonia nitrogen by zeolite and ceramic was 94%. In the release process, the ammonia nitrogen concentration increased significantly and then gradually returned to the normal level four hours after the shock load. The results indicated that the double-layer BAF had a high level of adaptability to the short-term ammonium shock load and long-term operation. The main factors influencing the dynamic process of ammonia nitrogen adsorption were the filter bed height, ammonia nitrogen concentration of influent, and flow rate. The bed depth service time （BDST） model was used to predict the relationship between the filter bed height and breakthrough time at different flow rates, and the results are reliable.展开更多
选择闽江河口典型芦苇(Phragmites australis)湿地为研究对象,基于野外氮负荷增强模拟试验(NN,无氮负荷处理,0 g N m^(-2)a^(-1);NL,低氮负荷处理,12.5 g N m^(-2)a^(-1);NM,中氮负荷处理,25.0 g N m^(-2)a^(-1);NH,高氮负荷处理,75.0 g...选择闽江河口典型芦苇(Phragmites australis)湿地为研究对象,基于野外氮负荷增强模拟试验(NN,无氮负荷处理,0 g N m^(-2)a^(-1);NL,低氮负荷处理,12.5 g N m^(-2)a^(-1);NM,中氮负荷处理,25.0 g N m^(-2)a^(-1);NH,高氮负荷处理,75.0 g N m^(-2)a^(-1)),通过获取不同年份冬季各氮负荷样地土壤开展室内培养实验,对比研究了氮负荷持续9个月(2021年12月,WT9)和21个月(2022年12月,WT21)后湿地土壤的N_(2)O产生过程。结果表明,氮负荷增强条件下湿地土壤不同过程的N_(2)O产生量发生了明显改变,不同年份土壤的N_(2)O总产生量均在NM处理下最高。异养反硝化作用对不同年份土壤的N_(2)O产生均存在较大的削弱作用,但其N_(2)O产生量整体随氮负荷时间的延长而增加;不同氮负荷处理下的非生物作用均是N_(2)O产生的重要过程,但其N_(2)O产生量在较短时期(WT9)随氮负荷水平的升高呈降低变化,而在较长时期(WT21)则呈增加趋势。不同氮负荷处理下非生物过程对N_(2)O产生的较大贡献主要与该区土壤铁锰、硫化物等含量丰富以及氮负荷增强条件下土壤酸碱状况(pH)的改变有关。氮负荷水平与温度对不同年份冬季土壤的N_(2)O产生过程均存在不同程度的交互影响,不同处理下的N_(2)O产生在WT9时期的较低温度下(5.5—11.5℃)以非生物作用为主,在WT21时期以硝化作用和非生物作用为主;而在较高温度下(17.5℃),不同年份冬季土壤的N_(2)O产生均以非生物作用和硝化细菌反硝化作用为主。研究发现,氮负荷增强改变了不同年份冬季土壤N_(2)O产生的生物和非生物贡献模式,其主要通过改变土壤养分状况来影响N_(2)O产生的生物或非生物过程。在闽江河口湿地冬季低温并叠加氮负荷增强条件下,其对土壤N_(2)O产生的综合影响表现为抵消效应,而这有助于降低该区冬季的N_(2)O排放量。展开更多
随着人类工业活动的开展,氮(N)排放和大气氮沉降显著增加。当大气氮沉降超过植物所能承受的临界负荷时可能使植物产生负面响应,导致物种丰度降低。菌根作为影响物种丰度的一个重要生物因素,可通过养分供给和菌丝网络机制影响植物的多样...随着人类工业活动的开展,氮(N)排放和大气氮沉降显著增加。当大气氮沉降超过植物所能承受的临界负荷时可能使植物产生负面响应,导致物种丰度降低。菌根作为影响物种丰度的一个重要生物因素,可通过养分供给和菌丝网络机制影响植物的多样性和群落结构。【目的】分析不同菌根类型林下草本植物氮沉降临界负荷的差异,探讨菌根类型如何影响林下草本植物对氮沉降的响应。【方法】基于森林草本植物长期氮沉降临界负荷数据库,结合已发表的文献资料,建立了“不同菌根类型森林林下草本植物对氮沉降响应的临界负荷数据库”,补充了森林优势种的菌根类型数据。该数据库共涵盖3种菌根类型:丛枝菌根(arbuscular mycorrhiza,AM)、外生菌根(ectomycorrhiza,ECM),以及受2种菌根共同侵染的双菌根(AM+ECM),以探究菌根类型对林下草本植物氮沉降临界负荷的影响。【结果】不同菌根类型森林下草本植物的氮沉降临界负荷存在显著差异(P<0.05)。AM+ECM型森林林下草本植物的氮沉降临界负荷最高,为9.28 kg N/(ha·a);ECM型次之,为8.41 kg N/(ha·a);AM型最低,为7.19 kg N/(ha·a)。在不同菌根类型森林中,不同功能群的林下草本植物(禾本科和非禾本科)对氮沉降响应的临界负荷与不同菌根类型林下全部草本植物的反应一致。氮沉降会引起林下草本植物的丰度变化,AM型森林草本植物物种丰度呈增加趋势,而含ECM的森林草本植物物种丰度以降低为主。【结论】菌根类型对林下草本植物的氮沉降临界负荷具有显著影响(P<0.05),这与不同菌根类型植物的生态位分化、凋落物氮含量浓度以及氮获取策略有关。此外,林下草本植物的丰度也会因菌根类型的不同而存在差异。展开更多
文摘This study proposed an integrated biogeochemical modeling of nitrogen load from anthropogenic and natural sources in Japan.Firstly,the nitrogen load(NL) from different sources such as crop,livestock,industrial plant,urban and rural resident was calculated by using datasets of fertilizer utilization,population distribution, land use map,and social census.Then,the nitrate leaching from soil layers in farmland,grassland and natural conditions was calculated by using a
文摘To protect important resources under their bureau’s purview, the United States National Park Service’s (NPS) Arctic Network (ARCN) has developed a series of “vital signs” that are to be periodically monitored. One of these vital signs focuses on wet and dry deposition of atmospheric chemicals and further, the establishment of critical load (CL) values (thresholds for ecological effects based on cumulative depositional loadings) for nitrogen (N), sulfur, and metals. As part of the ARCN terrestrial monitoring programs, samples of the feather moss Hylocomium splendens are being collected and analyzed as a cost-effective means to monitor atmospheric pollutant deposition in this region. Ultimately, moss data combined with refined CL values might be used to help guide future regulation of atmospheric contaminant sources potentially impacting Arctic Alaska. But first, additional long-term studies are needed to determine patterns of contaminant deposition as measured by moss biomonitors and to quantify ecosystem responses at particular loadings/ ranges of contaminants within Arctic Alaska. Herein we briefly summarize 1) current regulatory guidance related to CL values 2) derivation of CL models for N and metals, 3) use of mosses as biomonitors of atmospheric deposition and loadings, 4) preliminary analysis of vulnerabilities and risks associated with CL estimates for N, 5) preliminary analysis of existing data for characterization of CL values for N for interior Alaska and 6) implications for managers and future research needs.
文摘To evaluate the nitrogen pollution load in an aquifer, a water and nitrogen balance analysis was conducted over a thirty-five year period at five yearly intervals. First, we established a two-horizon model comprising a channel/soil horizon, and an aquifer horizon, with exchange of water between the aquifer and river. The nitrogen balance was estimated from the product of nitrogen concentration and water flow obtained from the water balance analysis. The aquifer nitrogen balance results were as follows: 1) In the aquifer horizon, the total nitrogen pollution load potential (NPLP) peaked in the period 1981-1990 at 1800 t·yr-1;following this the NPLP rapidly decreased to about 600 t·yr-1 in the period 2006-2010. The largest NPLP input component of 1000 t·yr-1 in the period 1976-1990 was from farmland. Subsequently, farmland NPLP decreased to only 400 t·yr-1 between 2006 and 2010. The second largest input component, 600 t·yr-1, was effluent from wastewater treatment works (WWTWs) in the period 1986-1990;this also decreased markedly to about 100 t·yr-1 between 2006 and 2010;2) The difference between input and output in the aquifer horizon, used as an index of groundwater pollution, peaked in the period 1986-1990 at about 1200 t·yr-1. This gradually decreased to about 200 t·yr-1 by 2006-2010. 3) The temporal change in NPLP coincided with the nitrogen concentration of the rivers in the study area. In addition, nitrogen concentrations in two test wells were 1.0 mg·l-1 at a depth of 150 m and only 0.25 mg·l-1 at 50 m, suggesting gradual percolation of the nitrogen polluted water deeper in the aquifer.
基金supported by the 2015 Science and Technology Project of Yunnan Province (Grant No. 2015FD075)Yunnan Normal University Scientific Research Training Fund Project (Grant No. ky2015-141)
文摘With the control of point source pollution in Dianchi Lake basin, and the expansion of Kunming city, non-point source pollution has become the main source pollution of urban water environment and Dianchi Lake. To reveal the nitrogen pollution characteristics in watershed, this research selected key monitoring points and sections at Baoxiang river basin in rainy season which is the peak transported time of non-point source pollution, the nitrogen and hydrological indicators are monitored systematically. The different forms of nitrogen are analyzed, the pollution load of nitrogen are calculated and studied at cardinal sections; combined with the literature data, we compared the water nitrogen characteristics of Dianchi basin and Taihu basin, the main results are as follows:(1) In summer, water nitrogen form of Baoxiang river in the Caohe area is dominated by nitrate nitrogen, while in other areas it is dominated by ammonia nitrogen which is accounted for 31%-50% of total nitrogen;(2) The water pollution loads of Baoxiang river tended to increase from upstream to downstream, from June to August the total nitrogen pollution mainly comes from urban areas and the pollution load is 166.408 t;(3) In Dianchi Lake watershed and Taihu Lake watershed nitrogen concentration of inflow river is higher than that of the lake, nitrate nitrogen concentration between inflow river and lake shows a little difference, while ammonia nitrogen concentration of inflow river is higher than that of the lake. The results can provide the theoretical basis for nonpoint source pollution control and urban water environment planning and improvement in Dianchi Lake Basin.
基金Project supported by the Science Research Foundation, Japan (No. 11460028).
文摘This study of Mikasa City in 2001, which analyzed N flow between N production and N load in seven agricultural and settlement subsystems, i.e., paddy, onion, wheat, vegetable, dairy, chicken, and citizen subsystems, aimed to compare N flow in each subsystem, to determine the main sources of the N load, and to evaluate the influence of agricultural production and food consumption on N cycling in a rural area. The results showed that in Mikasa city, 38.5% of the N load came from point sources and the remainder from non-point sources with intensive vegetable farming imparting a serious N load. Because of the internal N cycling in the dairy subsystem, chemical fertilizer application was reduced by 70.2%, and 23.72 Mg manure N was recycled to the field; therefore, the N utilization efficiency was raised from 18.1% to 35.1%. If all the manure N in the chicken subsystem was recycled, chemical fertilizer application would be reduced by 8.1% from the present level, and the point sources of N pollution would be reduced by 20.8%.
基金Under the auspices of the National Natural Science Foundation of China(No.52221003,42277044)。
文摘Baseflow is one of the major pathways of runoff in hilly areas,and its contributions to surface water resources and pollutant loads cannot be ignored.In this study,based on water quantity and quality data from 1988 to 2019 in hilly and low rainfall watersheds,we focused on the impact of long-term baseflow on nitrogen load using the load allocation based on the baseflow separation method.We also constructed a nitrogen balance model for the Chaohe River Basin of China from 2012 to 2021 to analyze the nitrogen accumulation in the basin.We used the baseflow nitrogen load lag analysis method to study the lag characteristics of the baseflow discharge process and analyzed the response and periodicity of baseflow nitrogen to precipitation and soil accumulation using time delay analysis.The res-ults showed that the contribution rate of baseflow nitrogen reached 69%and showed a slight increasing trend from 1988 to 2019.The ef-fects of changes in precipitation and nitrogen accumulation on the baseflow contribution was observed after 1-2 and 2 yr,respectively.After nitrogen accumulation,it entered the river channel through baseflow,which was already the main and continuous source of nitro-gen in rivers in hilly areas.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China(Grant No.2009ZX07317)
文摘An experiment was carried out to investigate the anti-ammonium shock load capacity of a biological aerated filter （BAF） composed of a double-layer bed. This bed was made up of a top layer of ceramic and a bottom layer of zeolite. The experiment shows that the anti-ammonium shock load process can be divided into two processes： adsorption and release. In the adsorption process, the total removal efficiency of ammonia nitrogen by zeolite and ceramic was 94%. In the release process, the ammonia nitrogen concentration increased significantly and then gradually returned to the normal level four hours after the shock load. The results indicated that the double-layer BAF had a high level of adaptability to the short-term ammonium shock load and long-term operation. The main factors influencing the dynamic process of ammonia nitrogen adsorption were the filter bed height, ammonia nitrogen concentration of influent, and flow rate. The bed depth service time （BDST） model was used to predict the relationship between the filter bed height and breakthrough time at different flow rates, and the results are reliable.
文摘选择闽江河口典型芦苇(Phragmites australis)湿地为研究对象,基于野外氮负荷增强模拟试验(NN,无氮负荷处理,0 g N m^(-2)a^(-1);NL,低氮负荷处理,12.5 g N m^(-2)a^(-1);NM,中氮负荷处理,25.0 g N m^(-2)a^(-1);NH,高氮负荷处理,75.0 g N m^(-2)a^(-1)),通过获取不同年份冬季各氮负荷样地土壤开展室内培养实验,对比研究了氮负荷持续9个月(2021年12月,WT9)和21个月(2022年12月,WT21)后湿地土壤的N_(2)O产生过程。结果表明,氮负荷增强条件下湿地土壤不同过程的N_(2)O产生量发生了明显改变,不同年份土壤的N_(2)O总产生量均在NM处理下最高。异养反硝化作用对不同年份土壤的N_(2)O产生均存在较大的削弱作用,但其N_(2)O产生量整体随氮负荷时间的延长而增加;不同氮负荷处理下的非生物作用均是N_(2)O产生的重要过程,但其N_(2)O产生量在较短时期(WT9)随氮负荷水平的升高呈降低变化,而在较长时期(WT21)则呈增加趋势。不同氮负荷处理下非生物过程对N_(2)O产生的较大贡献主要与该区土壤铁锰、硫化物等含量丰富以及氮负荷增强条件下土壤酸碱状况(pH)的改变有关。氮负荷水平与温度对不同年份冬季土壤的N_(2)O产生过程均存在不同程度的交互影响,不同处理下的N_(2)O产生在WT9时期的较低温度下(5.5—11.5℃)以非生物作用为主,在WT21时期以硝化作用和非生物作用为主;而在较高温度下(17.5℃),不同年份冬季土壤的N_(2)O产生均以非生物作用和硝化细菌反硝化作用为主。研究发现,氮负荷增强改变了不同年份冬季土壤N_(2)O产生的生物和非生物贡献模式,其主要通过改变土壤养分状况来影响N_(2)O产生的生物或非生物过程。在闽江河口湿地冬季低温并叠加氮负荷增强条件下,其对土壤N_(2)O产生的综合影响表现为抵消效应,而这有助于降低该区冬季的N_(2)O排放量。
文摘随着人类工业活动的开展,氮(N)排放和大气氮沉降显著增加。当大气氮沉降超过植物所能承受的临界负荷时可能使植物产生负面响应,导致物种丰度降低。菌根作为影响物种丰度的一个重要生物因素,可通过养分供给和菌丝网络机制影响植物的多样性和群落结构。【目的】分析不同菌根类型林下草本植物氮沉降临界负荷的差异,探讨菌根类型如何影响林下草本植物对氮沉降的响应。【方法】基于森林草本植物长期氮沉降临界负荷数据库,结合已发表的文献资料,建立了“不同菌根类型森林林下草本植物对氮沉降响应的临界负荷数据库”,补充了森林优势种的菌根类型数据。该数据库共涵盖3种菌根类型:丛枝菌根(arbuscular mycorrhiza,AM)、外生菌根(ectomycorrhiza,ECM),以及受2种菌根共同侵染的双菌根(AM+ECM),以探究菌根类型对林下草本植物氮沉降临界负荷的影响。【结果】不同菌根类型森林下草本植物的氮沉降临界负荷存在显著差异(P<0.05)。AM+ECM型森林林下草本植物的氮沉降临界负荷最高,为9.28 kg N/(ha·a);ECM型次之,为8.41 kg N/(ha·a);AM型最低,为7.19 kg N/(ha·a)。在不同菌根类型森林中,不同功能群的林下草本植物(禾本科和非禾本科)对氮沉降响应的临界负荷与不同菌根类型林下全部草本植物的反应一致。氮沉降会引起林下草本植物的丰度变化,AM型森林草本植物物种丰度呈增加趋势,而含ECM的森林草本植物物种丰度以降低为主。【结论】菌根类型对林下草本植物的氮沉降临界负荷具有显著影响(P<0.05),这与不同菌根类型植物的生态位分化、凋落物氮含量浓度以及氮获取策略有关。此外,林下草本植物的丰度也会因菌根类型的不同而存在差异。
