| 1 | Carbon,nitrogen and phosphorus stoichiometry in Pinus tabulaeformis forest ecosystems in warm temperate Shanxi Province,north China显示文摘Although carbon(C), nitrogen(N), and phosphorous(P) stoichiometric ratios are considered good indicators of nutrient excess/limitation and thus of ecosystem health, few reports have discussed the trends and the reciprocal effects of C:N:P stoichiometry in plant–litter–soil systems. The present study analyzed C:N:P ratios in four age groups of Chinese pine, Pinus tabulaeformis Carr., forests in Shanxi Province, China: plantation young forests(AY,<20 year-old); plantation middle-aged forests(AM, 21–30 year-old); natural young forests(NY,<30 year-old); and natural middle-aged forests(NM,31–50 year-old). The average C:N:P ratios calculated for tree, shrub, and herbaceous leaves, litter, and soil(0–100 cm) were generally higher in NY followed by NM,AM, and AY. C:N and C:P ratios were higher in litter than in leaves and soils, and reached higher values in the litter and leaves of young forests than in middle-aged forests;however, C:N and C:P ratios were higher in soils of middle-aged forests than in young forests. N:P ratios were higher in leaves than in litter and soils regardless of stand age; the consistent N:P<14 values found in all forests indicated N limitations. With plant leaves, C:P ratios were highest in trees, followed by herbs and shrubs, indicating a higher efficiency in tree leaf formation. C:N ratios decreased with increasing soil depth, whereas there was no trend for C:P and N:P ratios. C:N:P stoichiometry of forest foliage did not exhibit a consistent variation according to stand age. Research on the relationships between N:P, and P, N nutrient limits and the characteristics of vegetation nutrient adaptation need to be continued. | Ning Wang Fengzhen Fu Baitian Wang Ruijun Wang | 2018 | Journal of Forestry Research2018，29，6： | 4 |
| 2 | Thin Layer Identification of Jiedu Shengxue Granules and Determination of Notoginsenoside R1 Content显示文摘[Objectives]To establish the quality standard of hospital preparation Jiedu Shengxue granules.[Methods]Scleromitrion diffusum and Prunella vulgaris in Jiedu Shengxue granules were qualitatively identified by thin layer chromatography(TLC).A high performance liquid chromatography(HPLC)was established to determine the content of notoginsenoside R1 in the granule.[Results]The traditional Chinese medicinal materials in Jiedu Shengxue granules could be identified by TLC,and the characteristic spots were stable and clear.Notoginsenoside R1 had a good linear relationship in the range of 10.45-104.5μg/mL,with an average recovery of 98.52%and RSD=2.36%.[Conclusions]TLC and HPLC,as the quality control methods of Jiedu Shengxue granules,have high accuracy and good repeatability,which lays a foundation for the quality control of this mixture. | Zhenying FU Bing QING Yinghong HUANG Xianyi SHI Meiyan QIU Xian PENG Jiangcun WEI Fengzhen LI Wen ZHONG | 2024 | Medicinal Plant2024，15，1： | 0 |
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