为了正确认识桉树的耗水规律,利用热扩散探针法对2~3年生尾巨桉树干液流进行连续监测,分析其动态特征,并利用自动气象站同步测定林分气象条件,分析各气象因子与液流的关系。结果表明:2~3年生尾巨桉树干液流白天变化幅度较大,呈单峰曲线...为了正确认识桉树的耗水规律,利用热扩散探针法对2~3年生尾巨桉树干液流进行连续监测,分析其动态特征,并利用自动气象站同步测定林分气象条件,分析各气象因子与液流的关系。结果表明:2~3年生尾巨桉树干液流白天变化幅度较大,呈单峰曲线,占全天液流量的85%以上,变化特征与4年生尾巨桉相似,日平均树干液流密度为5.06 m L·h^(-1)·cm-2较4~6年生尾巨桉日平均液流密度大,夜间液流曲线平坦且较弱,夜晚平均树干液流密度为1.79 m L·h^(-1)·cm-2是4年生的3.8倍。不同月份间晴天的树干液流特征存在较大差异。不同天气条件下,晴天的液流启动时间最早(7:00),达到峰值所需时间最短(4.5 h),且液流峰值最大(18.47 m L·h^(-1)·cm-2),持续时间最长,日液流量也最大;其次是阴天,最后为雨天。2~3年生尾巨桉树干液流密度与大气温度、风速、太阳辐射、光合有效辐射以及水汽压亏缺呈极显著正相关(P<0.01),与空气湿度呈极显著负相关(P<0.01),相关系数分别为0.468、0.127、0.903、0.909、0.778、-0.626,这与4年生尾巨桉影响因子略有不同;日耗水量与大气温度、太阳辐射、光合有效辐射和水汽压亏缺呈极显著正相关(P<0.01),与空气湿度呈显著负相关(P<0.05),相关系数分别为0.489、0.489、0.523、0.408、-0.184。展开更多
Total concentration of heavy metals(Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5 yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Te...Total concentration of heavy metals(Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5 yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.展开更多
This study was aimed to evaluate the potential effects of rest grazing on organic carbon storage in Stipa grandis steppe of Inner Mongolia, China. Using potassium dichromate heating method, we analyzed the organic car...This study was aimed to evaluate the potential effects of rest grazing on organic carbon storage in Stipa grandis steppe of Inner Mongolia, China. Using potassium dichromate heating method, we analyzed the organic carbon storage of plant and soil in Stipa grand＆ steppe after rest grazing for 3, 6, and 9 yr. The results indicated that as the rest grazing ages prolonged, the biomass of aboveground parts, litter and belowground plant parts （roots） of the plant communities all increased, meanwhile the C content of the biomass increased with the rest grazing ages prolonging. For RG0, RG3a, RG6a, and RG9a, C storage in aboveground vegetation were 60.7, 76.9, 82.8 and 122.2 g C m2, respectively; C storage of litter were 5.1, 5.8, 20.4 and 25.5 g C m^-2, respectively; C storage of belowground roots （0-100 cm） were 475.2, 663.0, 1 115.0 and 1 867.3 g C m^-2, respectively; C storage in 0-100 cm soil were 13.97, 15.76, 18.60 and 32.41 kg C m^-2, respectively. As the rest grazing ages prolonged, the organic C storage in plant communities and soil increased. The C storage ofbelowground roots and soil organic C was mainly concentrated in 0-40 cm soil body. The increased soil organic C for RG3a accounted for 89.8% of the increased carbon in vegetation-soil system, 87.2% for RG6a, and 92.6% for RG9a. From the perspective of C sequestration cost, total cost for RG3a, RG6,, and RG9a were 2 903.4, 5 806.8 and 8 710.2 CNY haq, respectively. The cost reduced with the extension of rest grazing ages, 0.15 CNY kg^-1 C for RG3a, 0.11 CNY kg-~ C for RG6a and 0.04 CNY kg℃ for RG9a. From the growth characteristics of grassland plants, the spring was one of the two avoided grazing periods, timely rest grazing could effectively restore and update grassland vegetation, and was beneficial to the sustainable use of grassland. Organic C storage for RG9a was the highest, while the cost of C sequestration was the lowest. Therefore, spring rest grazing should be encouraged because it was proved to be a very efficient grassland use patter展开更多
Objective:To investigate antidiabetic,antihyperlipidemic and antioxidant activity of methanol extract of Tectona grandis(T.grandis) flowers(METGF) in streplozotocin(STZ) induced diabetic rats to supports its tradition...Objective:To investigate antidiabetic,antihyperlipidemic and antioxidant activity of methanol extract of Tectona grandis(T.grandis) flowers(METGF) in streplozotocin(STZ) induced diabetic rats to supports its traditional use.Methods:Acute toxicity study of METGF was carried out in rat to determine its dose for the antidiabetic study.Oral glucose tolerance test(OGTT) was performed to evaluate METGF effect on elevated blood glucose level.Diabetes was induced in rats by administration of STZ(60 mg/kg,ip.) and it was confirmed 72 h after induction.METGF was orally given to the diabetic rats up to 28 days and blood glucose level were estimated each week.On 28 day of the experiment,diabetic rats were sacrificed after the blood collection for the biochemical parameters analysis and liver,kidney was collected to determine antioxidants levels.Results: In acute toxicity,METGF did not show toxicity and death up to a dose 2 000 mg/kg in rats. Administration of METGF 100 and 200 mg/kg significantly(P【0.001) reduced blood glucose levels in OGTT and STZ-induced diabetic rats.Both doses of METGF treatment significantly(P【0.001, P【0.01 and P【0.05) increased body weight,serum insulin,haemoglobin(Hb) and total protein levels in diabetic rats.Also,MEGTF treatment reduced elevated glycosylated haemoglobin(HbA1c) and other biochemical parameters levels significantly(P【0.001) in diabetic rats.Altered lipid profiles and antioxidants levels were reversed to near normal in diabetic rats treated with METGF. Conclusions:These results concluded that METGF possesses antidiabetic,antihyperglycemic and antioxidant activity which supports its traditional use.展开更多
文摘为了正确认识桉树的耗水规律,利用热扩散探针法对2~3年生尾巨桉树干液流进行连续监测,分析其动态特征,并利用自动气象站同步测定林分气象条件,分析各气象因子与液流的关系。结果表明:2~3年生尾巨桉树干液流白天变化幅度较大,呈单峰曲线,占全天液流量的85%以上,变化特征与4年生尾巨桉相似,日平均树干液流密度为5.06 m L·h^(-1)·cm-2较4~6年生尾巨桉日平均液流密度大,夜间液流曲线平坦且较弱,夜晚平均树干液流密度为1.79 m L·h^(-1)·cm-2是4年生的3.8倍。不同月份间晴天的树干液流特征存在较大差异。不同天气条件下,晴天的液流启动时间最早(7:00),达到峰值所需时间最短(4.5 h),且液流峰值最大(18.47 m L·h^(-1)·cm-2),持续时间最长,日液流量也最大;其次是阴天,最后为雨天。2~3年生尾巨桉树干液流密度与大气温度、风速、太阳辐射、光合有效辐射以及水汽压亏缺呈极显著正相关(P<0.01),与空气湿度呈极显著负相关(P<0.01),相关系数分别为0.468、0.127、0.903、0.909、0.778、-0.626,这与4年生尾巨桉影响因子略有不同;日耗水量与大气温度、太阳辐射、光合有效辐射和水汽压亏缺呈极显著正相关(P<0.01),与空气湿度呈显著负相关(P<0.05),相关系数分别为0.489、0.489、0.523、0.408、-0.184。
文摘Total concentration of heavy metals(Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5 yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.
基金supported by the National Natural Science Foundation of China (31170435 and 31000242)the Key Technologies R&D Program of China during the 12th Five-Year Plan period (2012BAD13B07)
文摘This study was aimed to evaluate the potential effects of rest grazing on organic carbon storage in Stipa grandis steppe of Inner Mongolia, China. Using potassium dichromate heating method, we analyzed the organic carbon storage of plant and soil in Stipa grand＆ steppe after rest grazing for 3, 6, and 9 yr. The results indicated that as the rest grazing ages prolonged, the biomass of aboveground parts, litter and belowground plant parts （roots） of the plant communities all increased, meanwhile the C content of the biomass increased with the rest grazing ages prolonging. For RG0, RG3a, RG6a, and RG9a, C storage in aboveground vegetation were 60.7, 76.9, 82.8 and 122.2 g C m2, respectively; C storage of litter were 5.1, 5.8, 20.4 and 25.5 g C m^-2, respectively; C storage of belowground roots （0-100 cm） were 475.2, 663.0, 1 115.0 and 1 867.3 g C m^-2, respectively; C storage in 0-100 cm soil were 13.97, 15.76, 18.60 and 32.41 kg C m^-2, respectively. As the rest grazing ages prolonged, the organic C storage in plant communities and soil increased. The C storage ofbelowground roots and soil organic C was mainly concentrated in 0-40 cm soil body. The increased soil organic C for RG3a accounted for 89.8% of the increased carbon in vegetation-soil system, 87.2% for RG6a, and 92.6% for RG9a. From the perspective of C sequestration cost, total cost for RG3a, RG6,, and RG9a were 2 903.4, 5 806.8 and 8 710.2 CNY haq, respectively. The cost reduced with the extension of rest grazing ages, 0.15 CNY kg^-1 C for RG3a, 0.11 CNY kg-~ C for RG6a and 0.04 CNY kg℃ for RG9a. From the growth characteristics of grassland plants, the spring was one of the two avoided grazing periods, timely rest grazing could effectively restore and update grassland vegetation, and was beneficial to the sustainable use of grassland. Organic C storage for RG9a was the highest, while the cost of C sequestration was the lowest. Therefore, spring rest grazing should be encouraged because it was proved to be a very efficient grassland use patter
基金canara bank, Zamin uthukuli for the financial supports
文摘Objective:To investigate antidiabetic,antihyperlipidemic and antioxidant activity of methanol extract of Tectona grandis(T.grandis) flowers(METGF) in streplozotocin(STZ) induced diabetic rats to supports its traditional use.Methods:Acute toxicity study of METGF was carried out in rat to determine its dose for the antidiabetic study.Oral glucose tolerance test(OGTT) was performed to evaluate METGF effect on elevated blood glucose level.Diabetes was induced in rats by administration of STZ(60 mg/kg,ip.) and it was confirmed 72 h after induction.METGF was orally given to the diabetic rats up to 28 days and blood glucose level were estimated each week.On 28 day of the experiment,diabetic rats were sacrificed after the blood collection for the biochemical parameters analysis and liver,kidney was collected to determine antioxidants levels.Results: In acute toxicity,METGF did not show toxicity and death up to a dose 2 000 mg/kg in rats. Administration of METGF 100 and 200 mg/kg significantly(P【0.001) reduced blood glucose levels in OGTT and STZ-induced diabetic rats.Both doses of METGF treatment significantly(P【0.001, P【0.01 and P【0.05) increased body weight,serum insulin,haemoglobin(Hb) and total protein levels in diabetic rats.Also,MEGTF treatment reduced elevated glycosylated haemoglobin(HbA1c) and other biochemical parameters levels significantly(P【0.001) in diabetic rats.Altered lipid profiles and antioxidants levels were reversed to near normal in diabetic rats treated with METGF. Conclusions:These results concluded that METGF possesses antidiabetic,antihyperglycemic and antioxidant activity which supports its traditional use.
