Water and nitrogen （N） inputs are considered as the two main limiting factors affecting plant growth.Changes in these inputs are expected to alter the structure and composition of the plant community,thereby influen...Water and nitrogen （N） inputs are considered as the two main limiting factors affecting plant growth.Changes in these inputs are expected to alter the structure and composition of the plant community,thereby influencing biodiversity and ecosystem function.Snowfall is a form of precipitation in winter,and snow melting can recharge soil water and result in a flourish of ephemerals during springtime in the Gurbantunggut Desert,China.A bi-factor experiment was designed and deployed during the snow-covering season from 2009 to 2010.The experiment aimed to explore the effects of different snow-covering depths and N addition levels on ephemerals.Findings indicated that deeper snow cover led to the increases in water content in topsoil as well as density and coverage of ephemeral plants in the same N treatment; by contrast,N addition sharply decreased the density of ephemerals in the same snow treatment.Meanwhile,N addition exhibited a different effect on the growth of ephemeral plants：in the 50％ snow treatment,N addition limited the growth of ephemeral plants,showing that the height and the aboveground biomass of the ephemeral plants were lower than in those without N addition; while with the increases in snow depth （100％ and 150％ snow treatments）,N addition benefited the growth of the dominant individual plants.Species richness was not significantly affected by snow in the same N treatment.However,N addition significantly decreased the species richness in the same snow-covering depth.The primary productivity of ephemerals in the N addition increased with the increase of snow depth.These variations indicated that the effect of N on the growth of ephemerals was restricted by water supply.With plenty of water （100％ and 150％ snow treatments）,N addition contributed to the growth of ephemeral plants; while with less water （50％ snow treatment）,N addition restricted the growth of ephemeral plants.展开更多
[Objective] The paper was to clarify the bioactivity of trans-2-hexenal,oregano oil and thyme oil against Semiaphis heraclei and the synergistic effect of orange peel essential oil and organosilicon on the aphidicidal...[Objective] The paper was to clarify the bioactivity of trans-2-hexenal,oregano oil and thyme oil against Semiaphis heraclei and the synergistic effect of orange peel essential oil and organosilicon on the aphidicidal activity of the three agents.[Method] With S.heraclei,the dominant species of aphids in Lonicera japonica thunb.,as the test insect,the bioactivity and control effect were evaluated by the method of leaf dipping and foliar spraying.[Result] The indoor toxicity of thyme oil was the highest,with the LC_(50) of 1.793 mg/L.Adding additives significantly increased the toxicity of the agents to S.heraclei.Among them,trans-2-hexenal+OSi,oregano oil+OSi and thyme oil+OSi had obvious synergistic effects,with the toxicity coefficients of 1.80,1.48 and 1.45,respectively.Field test showed that the corrected control effect of thyme oil was the highest after con-ventional spraying,and the toxicities of the three agents were higher than that of the control group at 7 d post spraying.Under the condition of 20%reduction of three agents and adding organosilicon,the control effect was increased by about 10% at 1 d post spraying,which was higher than that of the control group at 4 d post spraying,and reached over 98% at 14 d post spraying.[Conclusion] Thyme oil has the highest toxicity and control effect on S.heraclei.Three agents combined with organosilicon have the obvious effect of reducing the quantity and increasing the efficiency,which has the potential for further development.展开更多
This study evaluated the effects of the inclusion of Ethiopian thyme (Thymus schimperi Ronninger) to natural pasture hay (NPH), noug seed cake (NSC), wheat bran (WB) and total mixed ration (TMR) on the chemical compos...This study evaluated the effects of the inclusion of Ethiopian thyme (Thymus schimperi Ronninger) to natural pasture hay (NPH), noug seed cake (NSC), wheat bran (WB) and total mixed ration (TMR) on the chemical composition and in Sacco dry matter (DM) degradability of the feeds. The Thyme plant used for the study was collected from Dinsho and Tarmaber districts in the highlands of Ethiopia. Samples of the TMR and NPH, WB and NSC with or without thyme were divided into two parts and ground to pass through 1 mm screen for chemical analysis and 2 mm screen for in sacco DM degradability. The TMR contained 50% NPH, 32.5% WB, 14% NSC, 3% molasses and 0.5% common salt. The feed ingredients (NPH, WB and NSC) and the TMR were incubated without thyme or with thyme substituting the diet at 8%, 16% and 24% levels of treatments. The chemical composition of all the feeds differed significantly (P In sacco rumen dry matter degradability of NPH, WB, NSC and TMR was increased (P in sacco DM degradability of NPH at all incubation hours was higher (P Thymus schimperi plant up to a level of 24% DM in feed can reasonably stimulate the growth and activity of the certain rumen microbes that promoted an improvement in ruminal DM degradability of the diet with the thyme inclusion.展开更多
植物提取物是畜禽饲料添加剂的重要组成部分,在畜禽养殖中起到抗氧化、抗炎、抗应激和提高生产性能的作用。目前植物提取物的制备多采用常规的有机溶剂(乙醇、氯仿和乙酸乙酯)提取,有机溶剂的易燃、易挥发和毒性会对提取人员造成伤害,...植物提取物是畜禽饲料添加剂的重要组成部分,在畜禽养殖中起到抗氧化、抗炎、抗应激和提高生产性能的作用。目前植物提取物的制备多采用常规的有机溶剂(乙醇、氯仿和乙酸乙酯)提取,有机溶剂的易燃、易挥发和毒性会对提取人员造成伤害,提取后的废液会造成环境的污染。天然低共熔溶剂(natural deep eutectic solvents, NADESs)是一种以初级代谢产物等天然成分为原料的新型绿色提取溶剂,具有制备简单、低毒或无毒、价廉易得、可生物降解、可回收利用等优点,是未来替代传统有机提取溶剂的新型溶剂,已广泛应用到化工、食品、中药提取等技术领域。文章综述了天然低共熔溶剂在植物提取物中的最新应用进展,旨在为天然低共熔溶剂的推广和应用提供指导。展开更多
Allelopathy plays an important role in the interaction between invasive and resident plants.Atmospheric nitrogen(N)deposition has become a global problem,but it is unclear whether N enrichment affects the interaction ...Allelopathy plays an important role in the interaction between invasive and resident plants.Atmospheric nitrogen(N)deposition has become a global problem,but it is unclear whether N enrichment affects the interaction between invasive and resident plants by affecting their allelopathy.Thus,we performed a greenhouse experiment in which the resident plant community was grown under two levels of invasion by S.canadensis(invasion vs.no invasion)and fully crossed with two levels of allelopathy(with or without adding activated carbon)and two levels of N addition(with or without).The resident plant communities were constructed with eight herbaceous species that often co-occur with S.canadensis.The results showed that both allelopathy of S.canadensis and the resident plants had obvious positive effects on their own growth.Nitrogen addition had more obvious positive effects on the resident plants under invasion than those that were not invaded.Moreover,N addition also altered the allelopathy of resident plants.Specifcally,N addition improved the allelopathy of resident plants when they were invaded but decreased the allelopathy of resident plants when they grew alone.Although nitrogen addition had no obvious effect on S.canadensis,it reduced the allelopathy of S.canadensis.These results suggest that N addition could improve the resistance of resident plants to invasion by improving the allelopathy of resident plants and reducing the allelopathy of S.canadensis.These fndings provide a scientifc basis to manage and control the S.canadensis invasion.展开更多
为了解从1998年至今的氮添加对植物响应研究的研究热点与发展趋势,本文利用VOSviewer和CiteSpace对Web of Science(WOS)中的相关文献进行了定量分析和可视化。运用描述性统计与可视化分析等方法,介绍了植物氮添加的研究热点、演化路径...为了解从1998年至今的氮添加对植物响应研究的研究热点与发展趋势,本文利用VOSviewer和CiteSpace对Web of Science(WOS)中的相关文献进行了定量分析和可视化。运用描述性统计与可视化分析等方法,介绍了植物氮添加的研究热点、演化路径和发展趋势,并对被引量较多、质量较高的文献进行深入分析,总结该领域的研究热点,把握该领域的发展方向。研究发现:(1)在该领域已经形成了较为稳定的合作群体;(2)发表论文的期刊主要在植物与土壤、土壤化学、生态学等研究领域,且下载的文献基本符合布拉德福定律;(3)中国、美国、加拿大等国家对植物氮添加领域的研究内容较多,且国家之间的联系也较为紧密,但中国发文质量有待提升;(4)从1998—2023年的领域发展的热点与动向表明研究该领域的内容更加深入与广泛。展开更多
基金funded by the National Basic Research Program of China(2009CB825102)the National Basic Research Program of China(2009CB421102E)+1 种基金the International Science & Technology Cooperation Program of China(2010DFA92720)the Natural Science Foundation of China(4117049)
文摘Water and nitrogen （N） inputs are considered as the two main limiting factors affecting plant growth.Changes in these inputs are expected to alter the structure and composition of the plant community,thereby influencing biodiversity and ecosystem function.Snowfall is a form of precipitation in winter,and snow melting can recharge soil water and result in a flourish of ephemerals during springtime in the Gurbantunggut Desert,China.A bi-factor experiment was designed and deployed during the snow-covering season from 2009 to 2010.The experiment aimed to explore the effects of different snow-covering depths and N addition levels on ephemerals.Findings indicated that deeper snow cover led to the increases in water content in topsoil as well as density and coverage of ephemeral plants in the same N treatment; by contrast,N addition sharply decreased the density of ephemerals in the same snow treatment.Meanwhile,N addition exhibited a different effect on the growth of ephemeral plants：in the 50％ snow treatment,N addition limited the growth of ephemeral plants,showing that the height and the aboveground biomass of the ephemeral plants were lower than in those without N addition; while with the increases in snow depth （100％ and 150％ snow treatments）,N addition benefited the growth of the dominant individual plants.Species richness was not significantly affected by snow in the same N treatment.However,N addition significantly decreased the species richness in the same snow-covering depth.The primary productivity of ephemerals in the N addition increased with the increase of snow depth.These variations indicated that the effect of N on the growth of ephemerals was restricted by water supply.With plenty of water （100％ and 150％ snow treatments）,N addition contributed to the growth of ephemeral plants; while with less water （50％ snow treatment）,N addition restricted the growth of ephemeral plants.
基金Supported by National Key R&D Program of China (2017YFC1701503)Major Science and Technology Innovation Project of Shandong Province (2018CXGC0309)。
文摘[Objective] The paper was to clarify the bioactivity of trans-2-hexenal,oregano oil and thyme oil against Semiaphis heraclei and the synergistic effect of orange peel essential oil and organosilicon on the aphidicidal activity of the three agents.[Method] With S.heraclei,the dominant species of aphids in Lonicera japonica thunb.,as the test insect,the bioactivity and control effect were evaluated by the method of leaf dipping and foliar spraying.[Result] The indoor toxicity of thyme oil was the highest,with the LC_(50) of 1.793 mg/L.Adding additives significantly increased the toxicity of the agents to S.heraclei.Among them,trans-2-hexenal+OSi,oregano oil+OSi and thyme oil+OSi had obvious synergistic effects,with the toxicity coefficients of 1.80,1.48 and 1.45,respectively.Field test showed that the corrected control effect of thyme oil was the highest after con-ventional spraying,and the toxicities of the three agents were higher than that of the control group at 7 d post spraying.Under the condition of 20%reduction of three agents and adding organosilicon,the control effect was increased by about 10% at 1 d post spraying,which was higher than that of the control group at 4 d post spraying,and reached over 98% at 14 d post spraying.[Conclusion] Thyme oil has the highest toxicity and control effect on S.heraclei.Three agents combined with organosilicon have the obvious effect of reducing the quantity and increasing the efficiency,which has the potential for further development.
文摘This study evaluated the effects of the inclusion of Ethiopian thyme (Thymus schimperi Ronninger) to natural pasture hay (NPH), noug seed cake (NSC), wheat bran (WB) and total mixed ration (TMR) on the chemical composition and in Sacco dry matter (DM) degradability of the feeds. The Thyme plant used for the study was collected from Dinsho and Tarmaber districts in the highlands of Ethiopia. Samples of the TMR and NPH, WB and NSC with or without thyme were divided into two parts and ground to pass through 1 mm screen for chemical analysis and 2 mm screen for in sacco DM degradability. The TMR contained 50% NPH, 32.5% WB, 14% NSC, 3% molasses and 0.5% common salt. The feed ingredients (NPH, WB and NSC) and the TMR were incubated without thyme or with thyme substituting the diet at 8%, 16% and 24% levels of treatments. The chemical composition of all the feeds differed significantly (P In sacco rumen dry matter degradability of NPH, WB, NSC and TMR was increased (P in sacco DM degradability of NPH at all incubation hours was higher (P Thymus schimperi plant up to a level of 24% DM in feed can reasonably stimulate the growth and activity of the certain rumen microbes that promoted an improvement in ruminal DM degradability of the diet with the thyme inclusion.
文摘植物提取物是畜禽饲料添加剂的重要组成部分,在畜禽养殖中起到抗氧化、抗炎、抗应激和提高生产性能的作用。目前植物提取物的制备多采用常规的有机溶剂(乙醇、氯仿和乙酸乙酯)提取,有机溶剂的易燃、易挥发和毒性会对提取人员造成伤害,提取后的废液会造成环境的污染。天然低共熔溶剂(natural deep eutectic solvents, NADESs)是一种以初级代谢产物等天然成分为原料的新型绿色提取溶剂,具有制备简单、低毒或无毒、价廉易得、可生物降解、可回收利用等优点,是未来替代传统有机提取溶剂的新型溶剂,已广泛应用到化工、食品、中药提取等技术领域。文章综述了天然低共熔溶剂在植物提取物中的最新应用进展,旨在为天然低共熔溶剂的推广和应用提供指导。
基金supported by the New Area Science and Technology Innovation Project(2022XACX1000)the Fundamental Research Funds for the Central Universities(QNTD202304)+4 种基金the National Key Research and Development Program of China(2021YFC2600400)the National Natural Science Foundation of China(31470475,31761123001)the Fundamental Research Funds for the Central Universities(2015ZCQ-BH-01)the China Major Science and Technology Program for Water Pollution Control and Treatment(2017ZX07602-004-003)the Beijing Municipal Education Commission through Innovative Transdisciplinary Program‘Ecological Restoration Engineering’.
文摘Allelopathy plays an important role in the interaction between invasive and resident plants.Atmospheric nitrogen(N)deposition has become a global problem,but it is unclear whether N enrichment affects the interaction between invasive and resident plants by affecting their allelopathy.Thus,we performed a greenhouse experiment in which the resident plant community was grown under two levels of invasion by S.canadensis(invasion vs.no invasion)and fully crossed with two levels of allelopathy(with or without adding activated carbon)and two levels of N addition(with or without).The resident plant communities were constructed with eight herbaceous species that often co-occur with S.canadensis.The results showed that both allelopathy of S.canadensis and the resident plants had obvious positive effects on their own growth.Nitrogen addition had more obvious positive effects on the resident plants under invasion than those that were not invaded.Moreover,N addition also altered the allelopathy of resident plants.Specifcally,N addition improved the allelopathy of resident plants when they were invaded but decreased the allelopathy of resident plants when they grew alone.Although nitrogen addition had no obvious effect on S.canadensis,it reduced the allelopathy of S.canadensis.These results suggest that N addition could improve the resistance of resident plants to invasion by improving the allelopathy of resident plants and reducing the allelopathy of S.canadensis.These fndings provide a scientifc basis to manage and control the S.canadensis invasion.
文摘为了解从1998年至今的氮添加对植物响应研究的研究热点与发展趋势,本文利用VOSviewer和CiteSpace对Web of Science(WOS)中的相关文献进行了定量分析和可视化。运用描述性统计与可视化分析等方法,介绍了植物氮添加的研究热点、演化路径和发展趋势,并对被引量较多、质量较高的文献进行深入分析,总结该领域的研究热点,把握该领域的发展方向。研究发现:(1)在该领域已经形成了较为稳定的合作群体;(2)发表论文的期刊主要在植物与土壤、土壤化学、生态学等研究领域,且下载的文献基本符合布拉德福定律;(3)中国、美国、加拿大等国家对植物氮添加领域的研究内容较多,且国家之间的联系也较为紧密,但中国发文质量有待提升;(4)从1998—2023年的领域发展的热点与动向表明研究该领域的内容更加深入与广泛。
