Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate th...Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate that the amount of elements from litter decomposition was less than that of the plant uptake from soil, but that from plant uptake was higher than that in soil with mineralization process released. On the other hand, in the open system including precipitation input and soil leaching output, because of great number of elements from precipitation into the open system, the element cycling(except N, P) in the Alpine tundra ecosystem was in a dynamic balance. In this study, it was also found that different organ of plants had significant difference in accumulating elements. Ca, Mg, P and N were accumulated more obviously in leaves, while Fe was in roots. The degree of concentration of elements in different tissues of the same organ of the plants also was different, a higher concentration of Ca, Mg, P and N in mesophyll than in nerve but Fe was in a reversed order. The phenomenon indicates (1) a variety of biochemical functions of different elements, (2) the elements in mesophyll were with a shorter turnover period than those in nerve or fibre, but higher utilization rate for plant. Therefore, this study implies the significance of keeping element dynamic balance in the alpine tundra ecosystem of Changbai Mountains.展开更多
Seed to soil contact is critical for successful germination and establishment.The seed coat micromorphology is a stable trait that has contributed significant information to the phylogenetic classification of angiospe...Seed to soil contact is critical for successful germination and establishment.The seed coat micromorphology is a stable trait that has contributed significant information to the phylogenetic classification of angiosperms.Seed morphology refers to the physical characteristics of seeds,such as their size,shape,color,texture,and structure.The characteristics can vary greatly among different plant species and can provide important information about the plants'life cycle,ecological requirements,and evolutionary history.The aim of this work was to describe the 34 species representing 23 botanical families that were collected to study the micromorphological features of seeds from Khaplu and Skardu mountainous area.Seed shape,color,and texture were observed under a light and scanning microscope and stereo microscope.Micromorphological and ultrastructural data have proved useful in determining seed plant evolution,classification,ecology,and phylogeny.Seed shapes varied from elliptic,oblong,ovate,pyramidal,and spherical.Surface sculpturing varied from rugulate,negative reticulate,reticulate,foveolate,granular and striated.The seed size varied enormously from very minute Matricaria chamomilla 0.33 mm×0.06 mm to very large seed Elaeagnus angustifolia 13.76 mm×4.70 mm.Epicuticular projections,anticlinal wall,periclinal wall,wall ornamentation,and seed texture were also studied under scanning electron microscopy.Most of the seed colors were brown and black except Carthamus tinctorius which exhibits creamy white color.A principal component analysis was used to identify the most outliers in seed micromorphology and provide a significant explanation.A taxonomic key based on micromorphological features has been constructed to assist botanists in identifying species and genera,and to support the conservation of seed bank resources.展开更多
基金The National Natural Science Foundation of China(No. 90211003) and the Innovation Program of the Chinese Acdemy of Sciences(No. KZCX3 SW 332)
文摘Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate that the amount of elements from litter decomposition was less than that of the plant uptake from soil, but that from plant uptake was higher than that in soil with mineralization process released. On the other hand, in the open system including precipitation input and soil leaching output, because of great number of elements from precipitation into the open system, the element cycling(except N, P) in the Alpine tundra ecosystem was in a dynamic balance. In this study, it was also found that different organ of plants had significant difference in accumulating elements. Ca, Mg, P and N were accumulated more obviously in leaves, while Fe was in roots. The degree of concentration of elements in different tissues of the same organ of the plants also was different, a higher concentration of Ca, Mg, P and N in mesophyll than in nerve but Fe was in a reversed order. The phenomenon indicates (1) a variety of biochemical functions of different elements, (2) the elements in mesophyll were with a shorter turnover period than those in nerve or fibre, but higher utilization rate for plant. Therefore, this study implies the significance of keeping element dynamic balance in the alpine tundra ecosystem of Changbai Mountains.
基金supported by Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R101),Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Seed to soil contact is critical for successful germination and establishment.The seed coat micromorphology is a stable trait that has contributed significant information to the phylogenetic classification of angiosperms.Seed morphology refers to the physical characteristics of seeds,such as their size,shape,color,texture,and structure.The characteristics can vary greatly among different plant species and can provide important information about the plants'life cycle,ecological requirements,and evolutionary history.The aim of this work was to describe the 34 species representing 23 botanical families that were collected to study the micromorphological features of seeds from Khaplu and Skardu mountainous area.Seed shape,color,and texture were observed under a light and scanning microscope and stereo microscope.Micromorphological and ultrastructural data have proved useful in determining seed plant evolution,classification,ecology,and phylogeny.Seed shapes varied from elliptic,oblong,ovate,pyramidal,and spherical.Surface sculpturing varied from rugulate,negative reticulate,reticulate,foveolate,granular and striated.The seed size varied enormously from very minute Matricaria chamomilla 0.33 mm×0.06 mm to very large seed Elaeagnus angustifolia 13.76 mm×4.70 mm.Epicuticular projections,anticlinal wall,periclinal wall,wall ornamentation,and seed texture were also studied under scanning electron microscopy.Most of the seed colors were brown and black except Carthamus tinctorius which exhibits creamy white color.A principal component analysis was used to identify the most outliers in seed micromorphology and provide a significant explanation.A taxonomic key based on micromorphological features has been constructed to assist botanists in identifying species and genera,and to support the conservation of seed bank resources.
