Based on soil monitoring data in nine sites of Jinhu, Xuyi and Hongze counties on the south bank of Hongze Lake from 1982 to 2013, changes in soil p H, total nitrogen（TN） content, available phosphorus content, organ...Based on soil monitoring data in nine sites of Jinhu, Xuyi and Hongze counties on the south bank of Hongze Lake from 1982 to 2013, changes in soil p H, total nitrogen（TN） content, available phosphorus content, organic matter（OM）content and cation exchange capacity（CEC） were analyzed. The results show that due to excessive application of chemical fertilizer in soil on the south bank of Hongze Lake, soil p H reduced by about 2 on average, while TN content and available phosphorus content in soil increased by more than one time and 2-5 times respectively. Soil acidification caused by agricultural production was very serious. In addition, low soil p H resulted in serious loss of soil cation, so that soil CEC in2013 accounted for less than 50% of that in 1982 and affected mineral nutrient metabolism of crops. Therefore, application of calcium, potassium and trace-element fertilizer should be paid more attention to during agricultural production in future.展开更多
Much attention has been paid to the stoichiometry of carbon(C), nitrogen(N), and phosphorus(P) because of their significance for plant growth and climate change. However, other nutrients, such as sulfur(S), are often ...Much attention has been paid to the stoichiometry of carbon(C), nitrogen(N), and phosphorus(P) because of their significance for plant growth and climate change. However, other nutrients, such as sulfur(S), are often ignored. In this study, we analyzed the stoichiometry of N, P, and S in leaves of 348 plant species in China's forests. The results show higher N content and higher molar ratios of N/P and P/S in Angiospermae than in Gymnospermae. At the family level, Ulmaceae absorbed more N and P from soils than other families, and Cupressaceae absorbed more S than other families. In addition,except for bamboo and other tropical forests, leaf N and P content of China's forests generally increased from low to middle latitudes and then slightly decreased or plateaued at high latitudes. Plant ecotypes, taxonomic groups, environmental conditions, atmospheric S precipitation, and soil-available N and P significantly affected the distribution and stoichiometry of leaf N, P, and S in China's forests.Our study indicates that China's forests are likely limited by P and S deficiencies which may increase in the future.展开更多
Inspired by the importance of Redfield-type C:N:P ratios in global soils,we looked for analogous patterns in peatlands and aimed at deciphering the potential affecting factors.By analyzing a suite of peatlands soil da...Inspired by the importance of Redfield-type C:N:P ratios in global soils,we looked for analogous patterns in peatlands and aimed at deciphering the potential affecting factors.By analyzing a suite of peatlands soil data(n = 1031),mean soil organic carbon(SOC),total nitrogen(TN) and total phosphorous(TP) contents were 50.51%,1.45% and 0.13%,respectively,while average C:N,C:P and N:P ratios were 26.72,1186.00 and 46.58,respectively.C:N ratios showed smaller variations across different vegetation coverage and had less spatial heterogeneity than C:P and N:P ratios.No consistent C:N:P ratio,though with a general value of 1245:47:1,was found for entire peatland soils in China.The Northeast China,Tibet,Zoigê Plateau and parts of Xinjiang had high soil SOC,TN,TP,and C:P ratio.Qinghai,parts of the lower reaches of the Yangtze River,and the coast zones have low TP and N:P ratio.Significant differences for SOC,TN,TP,C:N,C:P and N:P ratios were observed across groups categorized by predominant vegetation.Moisture,temperature and precipitation all closely related to SOC,TN,TP and their pairwise ratios.The hydrothermal coefficient(RH),defined as annual average precipitation divided by temperature,positively and significantly related to C:N,C:P and N:P ratios,implying that ongoing climate change may prejudice peatlands as carbon sinks during the past 50 years in China.展开更多
The mechanisms underlying the response of soil respiration(Rs) to nitrogen(N) addition remain to be explored in semiarid ecosystems. This study was conducted to determine the effect of N addition on soil microbial com...The mechanisms underlying the response of soil respiration(Rs) to nitrogen(N) addition remain to be explored in semiarid ecosystems. This study was conducted to determine the effect of N addition on soil microbial composition, Rs and the temperature sensitivity of Rs(Q10). The N addition experiment was carried out in a semiarid grassland in China, with N fertilizer application rates of 0, 2, 4, 8, 16, or 32 gN m-2yr-1. Microbial phospholipid fatty acids(PLFAs), Rs and Q10 were measured, and their relationships with soil properties were determined for three growing seasons. The results showed that N addition significantly increased the content of soil dissolved organic carbon(DOC) and inorganic nitrogen(IN), and decreased soil p H. With respect to soil microbes, N addition reduced soil PLFAs, reduced the fungi to bacteria ratio(F:B) and increased the gram-positive bacteria to gram-negative bacteria ratio(G+:G–). Rs under the N2, N4, N8, N16 and N32 treatments decreased by 2.58%, 14.86%, 22.62%, 23.97% and 19.87%, respectively, compared to the N0(control) treatment. The results of structural equation models showed that N addition reduced Rs by lowering soil PLFAs and altering the microbial composition. However, N addition had no significant effect on either Q10, soil total organic carbon(TOC) or total nitrogen(TN), indicating that N addition alleviated soil carbon loss and was unlikely to change the potential for a bigger loss under global warming.展开更多
基金Supported by the Surface Project of Natural Science Research for Higher Education in Jiangsu Province(13KJB210001)Innovation Planning Project for University Students in Jiangsu Province(201310323040Y)Key Technology R&D Program of Huai'an City,Jiangsu Province(SN13049)~~
文摘Based on soil monitoring data in nine sites of Jinhu, Xuyi and Hongze counties on the south bank of Hongze Lake from 1982 to 2013, changes in soil p H, total nitrogen（TN） content, available phosphorus content, organic matter（OM）content and cation exchange capacity（CEC） were analyzed. The results show that due to excessive application of chemical fertilizer in soil on the south bank of Hongze Lake, soil p H reduced by about 2 on average, while TN content and available phosphorus content in soil increased by more than one time and 2-5 times respectively. Soil acidification caused by agricultural production was very serious. In addition, low soil p H resulted in serious loss of soil cation, so that soil CEC in2013 accounted for less than 50% of that in 1982 and affected mineral nutrient metabolism of crops. Therefore, application of calcium, potassium and trace-element fertilizer should be paid more attention to during agricultural production in future.
基金support from the National Natural Science Foundation of China(41522207,41571130042)the State’s Key Project of Research and Development Plan of China(2016YFA0601002)
文摘Much attention has been paid to the stoichiometry of carbon(C), nitrogen(N), and phosphorus(P) because of their significance for plant growth and climate change. However, other nutrients, such as sulfur(S), are often ignored. In this study, we analyzed the stoichiometry of N, P, and S in leaves of 348 plant species in China's forests. The results show higher N content and higher molar ratios of N/P and P/S in Angiospermae than in Gymnospermae. At the family level, Ulmaceae absorbed more N and P from soils than other families, and Cupressaceae absorbed more S than other families. In addition,except for bamboo and other tropical forests, leaf N and P content of China's forests generally increased from low to middle latitudes and then slightly decreased or plateaued at high latitudes. Plant ecotypes, taxonomic groups, environmental conditions, atmospheric S precipitation, and soil-available N and P significantly affected the distribution and stoichiometry of leaf N, P, and S in China's forests.Our study indicates that China's forests are likely limited by P and S deficiencies which may increase in the future.
基金Under the auspices of National Key Research Program of China(No.2016YFC0500404-5)National Natural Science Foundation of China(No.41671081,41471081,41671087)Foundation of Jilin Province(No.20140520141JH)
文摘Inspired by the importance of Redfield-type C:N:P ratios in global soils,we looked for analogous patterns in peatlands and aimed at deciphering the potential affecting factors.By analyzing a suite of peatlands soil data(n = 1031),mean soil organic carbon(SOC),total nitrogen(TN) and total phosphorous(TP) contents were 50.51%,1.45% and 0.13%,respectively,while average C:N,C:P and N:P ratios were 26.72,1186.00 and 46.58,respectively.C:N ratios showed smaller variations across different vegetation coverage and had less spatial heterogeneity than C:P and N:P ratios.No consistent C:N:P ratio,though with a general value of 1245:47:1,was found for entire peatland soils in China.The Northeast China,Tibet,Zoigê Plateau and parts of Xinjiang had high soil SOC,TN,TP,and C:P ratio.Qinghai,parts of the lower reaches of the Yangtze River,and the coast zones have low TP and N:P ratio.Significant differences for SOC,TN,TP,C:N,C:P and N:P ratios were observed across groups categorized by predominant vegetation.Moisture,temperature and precipitation all closely related to SOC,TN,TP and their pairwise ratios.The hydrothermal coefficient(RH),defined as annual average precipitation divided by temperature,positively and significantly related to C:N,C:P and N:P ratios,implying that ongoing climate change may prejudice peatlands as carbon sinks during the past 50 years in China.
基金The National Natural Science Foundation of China(31770519)The National Key Research and Development Program of China(2017YFC0503805).
文摘The mechanisms underlying the response of soil respiration(Rs) to nitrogen(N) addition remain to be explored in semiarid ecosystems. This study was conducted to determine the effect of N addition on soil microbial composition, Rs and the temperature sensitivity of Rs(Q10). The N addition experiment was carried out in a semiarid grassland in China, with N fertilizer application rates of 0, 2, 4, 8, 16, or 32 gN m-2yr-1. Microbial phospholipid fatty acids(PLFAs), Rs and Q10 were measured, and their relationships with soil properties were determined for three growing seasons. The results showed that N addition significantly increased the content of soil dissolved organic carbon(DOC) and inorganic nitrogen(IN), and decreased soil p H. With respect to soil microbes, N addition reduced soil PLFAs, reduced the fungi to bacteria ratio(F:B) and increased the gram-positive bacteria to gram-negative bacteria ratio(G+:G–). Rs under the N2, N4, N8, N16 and N32 treatments decreased by 2.58%, 14.86%, 22.62%, 23.97% and 19.87%, respectively, compared to the N0(control) treatment. The results of structural equation models showed that N addition reduced Rs by lowering soil PLFAs and altering the microbial composition. However, N addition had no significant effect on either Q10, soil total organic carbon(TOC) or total nitrogen(TN), indicating that N addition alleviated soil carbon loss and was unlikely to change the potential for a bigger loss under global warming.
