This paper presents the effects of alternative nitrogen management regimes on production of Eucalyptus in tropics and sub-tropics carried out in autumn, 2011. The aim of the study was to review alternative nitrogen ma...This paper presents the effects of alternative nitrogen management regimes on production of Eucalyptus in tropics and sub-tropics carried out in autumn, 2011. The aim of the study was to review alternative nitrogen management regimes that could enhance the positive effects and reduce negative effects of different Eucalyptus species in the perspective of smallholders. Literature review was used to survey the alternative nitrogen management regimes on eucalyptus trees. There was a significant improvement （P ≤ 0.01） in mean annual increment （MAI） as measured at seven years of Eucalyptus tereticornis in the plots planted with only legume, pueraria and stylosanthes, compared to that of the control on altitude 150 m and rainfall of 2,000 mm at the age of seven years, The MAI of Eucalyptus urophylla and Eucalyptus camaldulensis in plots planted with beans and rice shows a significant improvement （P ≤ 0.05） over the control treatment. Only the plots treated with nitrogen fertilizer 550 kg/ha showed significant improvement （P ≤ 0.05） in terms of MAI of Eucalyptus nitens, compared to the control treatment. In general, it can be concluded that as these alternative management regimes enhance productivity of Eucalyptus woodlots, the challenge for the small-scale farmers is on how to manage them sustainably. Therefore, forest policies that take consideration of increasing production of Eucalyptus and managing biodiversity with reference to these alternative management regimes should be developed in tropics and sub-tropics.展开更多
The chemical and biological mechanisms of life processes mostly consist of multistep and programmed processes at nanoscale levels. Interestingly enough, cell, the basic functional unit and platform that maintains life...The chemical and biological mechanisms of life processes mostly consist of multistep and programmed processes at nanoscale levels. Interestingly enough, cell, the basic functional unit and platform that maintains life processes, is composed of various organelles fulfilling sophisticated functions through the precise control on the biomolecules （e.g., proteins, phospholipid, nucleic acid and ions） in a spatial dimension of nanoscale sizes. Thus, understanding of the activities of manufactured nanoscale materials including their interaction with biological sys- tems is of great significance in chemistry, materials sci- ence, life science, medicine, environmental science and toxicology. In this brief review, we summarized the recent advances in nanotoxicological chemistry through the dis- section of pivotal factors （primarily focusing on dose and nanosurface chemistry） in determining nanomaterial- induced biological/toxic responses with particular empha- sis on the nanomaterial bioaccumulation （and interaction organs or target organs） at intact animal level. Due to the volume of manufacture and material application, we deliberately discussed carbon nanotubes, metal/metal oxide nanomaterials and quantum dots, severing as representativematerial types to illustrate the impact of dose and nanosurface chemistry in these toxicological scenarios. Finally, we have also delineated the grand challenges in this field in a conceptual framework of nanotoxicological chemistry. It is noted that this review is a part of our persistent endeavor of building the systematic knowledge framework for toxicological properties of engineered nanomaterials.展开更多
文摘This paper presents the effects of alternative nitrogen management regimes on production of Eucalyptus in tropics and sub-tropics carried out in autumn, 2011. The aim of the study was to review alternative nitrogen management regimes that could enhance the positive effects and reduce negative effects of different Eucalyptus species in the perspective of smallholders. Literature review was used to survey the alternative nitrogen management regimes on eucalyptus trees. There was a significant improvement （P ≤ 0.01） in mean annual increment （MAI） as measured at seven years of Eucalyptus tereticornis in the plots planted with only legume, pueraria and stylosanthes, compared to that of the control on altitude 150 m and rainfall of 2,000 mm at the age of seven years, The MAI of Eucalyptus urophylla and Eucalyptus camaldulensis in plots planted with beans and rice shows a significant improvement （P ≤ 0.05） over the control treatment. Only the plots treated with nitrogen fertilizer 550 kg/ha showed significant improvement （P ≤ 0.05） in terms of MAI of Eucalyptus nitens, compared to the control treatment. In general, it can be concluded that as these alternative management regimes enhance productivity of Eucalyptus woodlots, the challenge for the small-scale farmers is on how to manage them sustainably. Therefore, forest policies that take consideration of increasing production of Eucalyptus and managing biodiversity with reference to these alternative management regimes should be developed in tropics and sub-tropics.
基金supported by the National Natural Science Foundation of China(11305182,21277037,21320102003)the National Basic Research Program of China(2011CB933403)
文摘The chemical and biological mechanisms of life processes mostly consist of multistep and programmed processes at nanoscale levels. Interestingly enough, cell, the basic functional unit and platform that maintains life processes, is composed of various organelles fulfilling sophisticated functions through the precise control on the biomolecules （e.g., proteins, phospholipid, nucleic acid and ions） in a spatial dimension of nanoscale sizes. Thus, understanding of the activities of manufactured nanoscale materials including their interaction with biological sys- tems is of great significance in chemistry, materials sci- ence, life science, medicine, environmental science and toxicology. In this brief review, we summarized the recent advances in nanotoxicological chemistry through the dis- section of pivotal factors （primarily focusing on dose and nanosurface chemistry） in determining nanomaterial- induced biological/toxic responses with particular empha- sis on the nanomaterial bioaccumulation （and interaction organs or target organs） at intact animal level. Due to the volume of manufacture and material application, we deliberately discussed carbon nanotubes, metal/metal oxide nanomaterials and quantum dots, severing as representativematerial types to illustrate the impact of dose and nanosurface chemistry in these toxicological scenarios. Finally, we have also delineated the grand challenges in this field in a conceptual framework of nanotoxicological chemistry. It is noted that this review is a part of our persistent endeavor of building the systematic knowledge framework for toxicological properties of engineered nanomaterials.
