In order to investigate effect of fertilization on water-soluble organic N (WSON) in the soils under chestnut stands,a fertilization experiment was carried out in Lin-an county in Zhejiang province. The results of thi...In order to investigate effect of fertilization on water-soluble organic N (WSON) in the soils under chestnut stands,a fertilization experiment was carried out in Lin-an county in Zhejiang province. The results of this study showed that fertilization increased WSON in the soils under chestnut stands. Excessive chemical fertilizer addition or combined application of chemical fertilizers and organic manure had most strong effects by increasing the concentrations of WSON in the soils respectively by 5.68 and 1.94 times,compared with the unfertilized control,There was no difference in WSON concentrations in the soils among the treatments with routine chemical fertilizer rate,organic manure alone and unfertilized control. Excessive fertilizer application induced the highest ratio of WSON/total N (5.76%),which was markedly greater than that done by other three treatments. The ratio of WSON/hydrolyzed N ranged from 9.34% to 37.04% with average value of 26.78%. The highest ratio of hydrolyzed N/total N (37.04%) was found from the treatments of excessive fertilizer application and the ratio was markedly greater than that of other three treatments. The correlation analysis showed that there were significant correlations between WSON and soil total N,hydrolyzed N,water soluble total N,water soluble NH4+-N or water soluble NO3-N. The corresponding correlation coefficients were 0.565 1,0.918 6,0.998 6,0.9939 and 0.5401,respectively.展开更多
在太原市运用中流量采样器进行24 h PM_(2.5)样品采集,并进行水溶性有机碳(WSOC)、水溶性总氮(WSTN)、水溶性有机氮(WSON)以及无机离子分析,探究其浓度、组成、时间变化特征与来源。结果表明,冬季采暖期太原PM_(2.5)中WSON日平均浓度为(...在太原市运用中流量采样器进行24 h PM_(2.5)样品采集,并进行水溶性有机碳(WSOC)、水溶性总氮(WSTN)、水溶性有机氮(WSON)以及无机离子分析,探究其浓度、组成、时间变化特征与来源。结果表明,冬季采暖期太原PM_(2.5)中WSON日平均浓度为(10.0±4.9)μg/m^3,平均占WSTN的44%。在无霾天(能见度>10 km)、微霾天(5 km≤能见度≤10 km)和重霾天(能见度<5 km),WSON分别为(1.1±1.0)、(4.3±2.9)、(15.5±4.5)μg/m^3。WSON/WSOC质量比从无霾天、微霾天到重灰霾天呈逐步增大趋势,其均值分别为0.3±0.5、0.47±0.16、0.64±0.15。PCA/APCS模型分析表明,燃煤燃烧、生物质燃烧以及汽车尾气排放的混合源对WSON的贡献率为21.4%,建筑扬尘对WSON的贡献率为1.3%,烹饪对WSON的贡献率为1.7%。展开更多
森林生态系统作为生物圈的重要组成部分,维持着全球植被碳库的86%和土壤碳库的40%（Houghton et al.,2001;胡会峰等,2006）。因此,森林在调节全球气候、维持全球碳平衡方面起着非常重要的作用（Fang et al.,2001;Woodbury et al.,2007;H...森林生态系统作为生物圈的重要组成部分,维持着全球植被碳库的86%和土壤碳库的40%（Houghton et al.,2001;胡会峰等,2006）。因此,森林在调节全球气候、维持全球碳平衡方面起着非常重要的作用（Fang et al.,2001;Woodbury et al.,2007;Hu et al.,2008）。然而,展开更多
采用盆栽控制试验对黄土丘陵区白羊草在不同CO_2浓度(400和800μmol·mol^(-1))和施氮水平(0、2.5、5.0 g N·m^(-2)·a^(-1))条件下根际和非根际土壤水溶性有机碳(DOC}和水溶性有机氮(DON)的变化特征进行研究.结果表明:CO_...采用盆栽控制试验对黄土丘陵区白羊草在不同CO_2浓度(400和800μmol·mol^(-1))和施氮水平(0、2.5、5.0 g N·m^(-2)·a^(-1))条件下根际和非根际土壤水溶性有机碳(DOC}和水溶性有机氮(DON)的变化特征进行研究.结果表明:CO_2浓度升高对白羊草根际和非根际土壤DOC、水溶性总氮(DTN)、DON、水溶性铵态氮(NH_4^+-N)、水溶性硝态氮(NO_3^-N)含量均无显著影响.施氮显著提高了根际和非根际土壤DTN、NO_3^-N含量和根际土壤DON含量,显著降低了根际土壤DOC/DON.在各处理条件下,根际土壤DTN、NO_3^-N和DON含量均显著低于非根际土壤,根际土壤DOC/DON显著高于非根际土壤.短期CO_2浓度升高对黄土丘陵区土壤水溶性有机碳、氮含量无显著影响,而氮沉降的増加在一定程度上改善了土壤中水溶性氮素缺乏的状况,但并不足以满足植被对水溶性氮素的需求.展开更多
文摘In order to investigate effect of fertilization on water-soluble organic N (WSON) in the soils under chestnut stands,a fertilization experiment was carried out in Lin-an county in Zhejiang province. The results of this study showed that fertilization increased WSON in the soils under chestnut stands. Excessive chemical fertilizer addition or combined application of chemical fertilizers and organic manure had most strong effects by increasing the concentrations of WSON in the soils respectively by 5.68 and 1.94 times,compared with the unfertilized control,There was no difference in WSON concentrations in the soils among the treatments with routine chemical fertilizer rate,organic manure alone and unfertilized control. Excessive fertilizer application induced the highest ratio of WSON/total N (5.76%),which was markedly greater than that done by other three treatments. The ratio of WSON/hydrolyzed N ranged from 9.34% to 37.04% with average value of 26.78%. The highest ratio of hydrolyzed N/total N (37.04%) was found from the treatments of excessive fertilizer application and the ratio was markedly greater than that of other three treatments. The correlation analysis showed that there were significant correlations between WSON and soil total N,hydrolyzed N,water soluble total N,water soluble NH4+-N or water soluble NO3-N. The corresponding correlation coefficients were 0.565 1,0.918 6,0.998 6,0.9939 and 0.5401,respectively.
文摘森林生态系统作为生物圈的重要组成部分,维持着全球植被碳库的86%和土壤碳库的40%（Houghton et al.,2001;胡会峰等,2006）。因此,森林在调节全球气候、维持全球碳平衡方面起着非常重要的作用（Fang et al.,2001;Woodbury et al.,2007;Hu et al.,2008）。然而,
文摘采用盆栽控制试验对黄土丘陵区白羊草在不同CO_2浓度(400和800μmol·mol^(-1))和施氮水平(0、2.5、5.0 g N·m^(-2)·a^(-1))条件下根际和非根际土壤水溶性有机碳(DOC}和水溶性有机氮(DON)的变化特征进行研究.结果表明:CO_2浓度升高对白羊草根际和非根际土壤DOC、水溶性总氮(DTN)、DON、水溶性铵态氮(NH_4^+-N)、水溶性硝态氮(NO_3^-N)含量均无显著影响.施氮显著提高了根际和非根际土壤DTN、NO_3^-N含量和根际土壤DON含量,显著降低了根际土壤DOC/DON.在各处理条件下,根际土壤DTN、NO_3^-N和DON含量均显著低于非根际土壤,根际土壤DOC/DON显著高于非根际土壤.短期CO_2浓度升高对黄土丘陵区土壤水溶性有机碳、氮含量无显著影响,而氮沉降的増加在一定程度上改善了土壤中水溶性氮素缺乏的状况,但并不足以满足植被对水溶性氮素的需求.
