研究火炬树Rhus typhina克隆分株与荆条Vitex negundo var. heterophylla克隆分株光合生理生态日变化特征,揭示它们对火炬树单优群落下层与外缘不同光强的生态适应差异。分别火炬树单优群落下层和外缘,比较测定了火炬树与荆条克隆分株...研究火炬树Rhus typhina克隆分株与荆条Vitex negundo var. heterophylla克隆分株光合生理生态日变化特征,揭示它们对火炬树单优群落下层与外缘不同光强的生态适应差异。分别火炬树单优群落下层和外缘,比较测定了火炬树与荆条克隆分株的光合日进程。结果表明:①由于光合有效辐射降低,火炬树克隆分株与火炬树单优群落内荆条竞争极为有限的光合有效辐射,群落外缘本土灌木种荆条的净光合峰值为9.183μmol.m-2.s-1,群落内荆条的净光合速率仅为1.396μmol.m-2.s-1,同时荆条净光合速率峰值还低于火炬树克隆分株。②在13:00至17:00,火炬树克隆分株在其单优群落内的Fv/Fm值高于荆条克隆分株,证实火炬树克隆分株适应弱光能力超过荆条。火炬树通过克隆繁殖形成高度的自遮荫现象,是引起火炬树克隆分株与荆条克隆分株之间光合生理生态差异的重要原因。展开更多
In this work, the difference in number of dominant species in a community on global scale and successional trajectories was analyzed based on the published data. We explained the reasons of these differ-ences using a ...In this work, the difference in number of dominant species in a community on global scale and successional trajectories was analyzed based on the published data. We explained the reasons of these differ-ences using a resource availability hypothesis, proposed in this work, that the distribution of available resource determined the pattern of commu-nity dominance. The results showed that on global scale the number of dominant species of community varied across latitudinal forest zone, namely from single-species dominance in boreal and temperate forest to multi-species codominance, even no dominant species in tropical forest. This was consistent with the pattern of resource distribution on global scale. Similarly, in successional trajectories, the number of dominant species gradually radiated from single-species dominance to multi-species codominance, even no dominant species in tropical forest. The changing available resources in trajectories were responsible for this difference. By contrary, a community was often dominated by single species in temperate or boreal forest. This was determined by the low available resource, especially low available water and temperature. In boreal forest, low temperature greatly reduced availability of water and nutrient, which were responsible for the single-species dominance. In addition, the conclusion that high available resources sustained low dominance of community might be deduced, based on the fact that the dominance of community declined with the increasing of species diversity. To sum up, the richer the available resources were, the lower the dominance of community was, and vice versa. The hypothesis that the resource availability controlled the dominance of community could well elucidate the difference of community dominance on global and community scale.展开更多
[Objective] This paper aimed to study the tissue culture and rapid propagation technology of superior individuals of Lonicera edulis Turcz. [Method] Several superior individuals of Lonicera edulis Turcz were used as m...[Objective] This paper aimed to study the tissue culture and rapid propagation technology of superior individuals of Lonicera edulis Turcz. [Method] Several superior individuals of Lonicera edulis Turcz were used as materials for selecting the primary medium, subculture medium, rooting medium and acclimatization substrate during the tissue culture and rapid propagation. [Result] 6-BA was the optimal cytokinin for tissue culture of Lonicera edulis Turcz, compared with ZT; modified MS＋1.0 mg/L of 6-BA ＋ 0.2 mg/L of IBA was the optimal medium as primary and subculture medium, modified MS＋ 1.5 mg/L of IBA was the optimal medium for rooting of Lonicera edulis Turcz, the rooting rate had achieved 100% after cultured for 30 d. The optimal substrate for transplanting plantlets of Lonicera edulis Turcz was composed of humus and perlite （1∶ 1, V/V）, survival rate was as high as 95% after 30 d. [Conclusion] This study provided basis for the rapid propagation of superior seedlings of Lonicera edulis Turcz, as well as the establishment of industrialized breeding technical system and the implementation of scale production.展开更多
文摘研究火炬树Rhus typhina克隆分株与荆条Vitex negundo var. heterophylla克隆分株光合生理生态日变化特征,揭示它们对火炬树单优群落下层与外缘不同光强的生态适应差异。分别火炬树单优群落下层和外缘,比较测定了火炬树与荆条克隆分株的光合日进程。结果表明:①由于光合有效辐射降低,火炬树克隆分株与火炬树单优群落内荆条竞争极为有限的光合有效辐射,群落外缘本土灌木种荆条的净光合峰值为9.183μmol.m-2.s-1,群落内荆条的净光合速率仅为1.396μmol.m-2.s-1,同时荆条净光合速率峰值还低于火炬树克隆分株。②在13:00至17:00,火炬树克隆分株在其单优群落内的Fv/Fm值高于荆条克隆分株,证实火炬树克隆分株适应弱光能力超过荆条。火炬树通过克隆繁殖形成高度的自遮荫现象,是引起火炬树克隆分株与荆条克隆分株之间光合生理生态差异的重要原因。
基金This paper was supported by Normal Projects of National Natural Science Foundation of China (30870419, 40971151)Project "948" of State Forestry Administration (2006-4-13)Scientific Research Fund of Hunan Provincial Education Department (08C674)
文摘In this work, the difference in number of dominant species in a community on global scale and successional trajectories was analyzed based on the published data. We explained the reasons of these differ-ences using a resource availability hypothesis, proposed in this work, that the distribution of available resource determined the pattern of commu-nity dominance. The results showed that on global scale the number of dominant species of community varied across latitudinal forest zone, namely from single-species dominance in boreal and temperate forest to multi-species codominance, even no dominant species in tropical forest. This was consistent with the pattern of resource distribution on global scale. Similarly, in successional trajectories, the number of dominant species gradually radiated from single-species dominance to multi-species codominance, even no dominant species in tropical forest. The changing available resources in trajectories were responsible for this difference. By contrary, a community was often dominated by single species in temperate or boreal forest. This was determined by the low available resource, especially low available water and temperature. In boreal forest, low temperature greatly reduced availability of water and nutrient, which were responsible for the single-species dominance. In addition, the conclusion that high available resources sustained low dominance of community might be deduced, based on the fact that the dominance of community declined with the increasing of species diversity. To sum up, the richer the available resources were, the lower the dominance of community was, and vice versa. The hypothesis that the resource availability controlled the dominance of community could well elucidate the difference of community dominance on global and community scale.
基金Supported by the National Natural Science Fundation of China(30960231)Project of the State Forestry Administration(2005-06)~~
文摘[Objective] This paper aimed to study the tissue culture and rapid propagation technology of superior individuals of Lonicera edulis Turcz. [Method] Several superior individuals of Lonicera edulis Turcz were used as materials for selecting the primary medium, subculture medium, rooting medium and acclimatization substrate during the tissue culture and rapid propagation. [Result] 6-BA was the optimal cytokinin for tissue culture of Lonicera edulis Turcz, compared with ZT; modified MS＋1.0 mg/L of 6-BA ＋ 0.2 mg/L of IBA was the optimal medium as primary and subculture medium, modified MS＋ 1.5 mg/L of IBA was the optimal medium for rooting of Lonicera edulis Turcz, the rooting rate had achieved 100% after cultured for 30 d. The optimal substrate for transplanting plantlets of Lonicera edulis Turcz was composed of humus and perlite （1∶ 1, V/V）, survival rate was as high as 95% after 30 d. [Conclusion] This study provided basis for the rapid propagation of superior seedlings of Lonicera edulis Turcz, as well as the establishment of industrialized breeding technical system and the implementation of scale production.
