The Dipterocarpaceae family is famous for timber productions in Southeast Asia. The Shuangxi tropical arboretum in Taiwan introduced some dipterocarp species in 1935. However, the changes in abundance and regeneration...The Dipterocarpaceae family is famous for timber productions in Southeast Asia. The Shuangxi tropical arboretum in Taiwan introduced some dipterocarp species in 1935. However, the changes in abundance and regeneration of each dipterocarp species are unknown. This study aimed to investigate their diameters patterns and regeneration ability over a long period. The results showed that only four dipterocarp species were survived in this arboretum. An individual plant of Dipterocarpus gracilis Blume had a diameter of 5.7 cm. A young seedling was 90 cm in height, and some fruits germinated directly on the ground. A few fruits of Dipterocarpus grandiflorus (Blanco) Blanco were collected;however, and no seedlings have been found thus far, and its annual growth rate was 2.82% as the fastest growth speed. The annual growth rate of Rubroshorea polysperma (Blanco) P. S. Ashton & J. Heck was 2.32%, which is the second growth speed among the different species. Moreover, the abundance of R. polysperma increased as the fruits germinated. In particular, an uneven-aged forest of R. polysperma was established near the southwest area of the No. 2225 nature conservation protection forest, and an individual with a 100 cm DBH was also found. The fruits of Rubroshorea palosapis (Blanco) P. S. Ashton & J. Heck. could not be collected, but a young seedling appeared, with a height of approximately 150 cm. Therefore, Taiwan should be considered as the new distribution site for the Dipterocarpaceae family, all four dipterocarp species can grow in this area and need to be protected carefully.展开更多
A strong effect of climate on phenological events in conifers has been documented by several studies. To study adaptation of reproductive processes in Abies sibirica Ledeb. to changing environment, the phenology of th...A strong effect of climate on phenological events in conifers has been documented by several studies. To study adaptation of reproductive processes in Abies sibirica Ledeb. to changing environment, the phenology of the development of the species male reproductive cones at introduction was studied. Phenological shift in Abies sibirica meiosis and pollination was observed. An earlier start of male bud reproductive development is founded in V.N. Sukachev Institute of Forest Arboretum resulted in increasing meiosis and pollen irregularities. Insufficient high quality pollen in the species at its pollination stage may be a major factor responsible for the incapability to produce the viable seeds in quantities sufficient for pollination in seed gardens. Responses of the fir male cone development to the current environmental conditions at the Arboretum may be considered as a model of adaptation of the species to climatic changes.展开更多
文摘The Dipterocarpaceae family is famous for timber productions in Southeast Asia. The Shuangxi tropical arboretum in Taiwan introduced some dipterocarp species in 1935. However, the changes in abundance and regeneration of each dipterocarp species are unknown. This study aimed to investigate their diameters patterns and regeneration ability over a long period. The results showed that only four dipterocarp species were survived in this arboretum. An individual plant of Dipterocarpus gracilis Blume had a diameter of 5.7 cm. A young seedling was 90 cm in height, and some fruits germinated directly on the ground. A few fruits of Dipterocarpus grandiflorus (Blanco) Blanco were collected;however, and no seedlings have been found thus far, and its annual growth rate was 2.82% as the fastest growth speed. The annual growth rate of Rubroshorea polysperma (Blanco) P. S. Ashton & J. Heck was 2.32%, which is the second growth speed among the different species. Moreover, the abundance of R. polysperma increased as the fruits germinated. In particular, an uneven-aged forest of R. polysperma was established near the southwest area of the No. 2225 nature conservation protection forest, and an individual with a 100 cm DBH was also found. The fruits of Rubroshorea palosapis (Blanco) P. S. Ashton & J. Heck. could not be collected, but a young seedling appeared, with a height of approximately 150 cm. Therefore, Taiwan should be considered as the new distribution site for the Dipterocarpaceae family, all four dipterocarp species can grow in this area and need to be protected carefully.
文摘A strong effect of climate on phenological events in conifers has been documented by several studies. To study adaptation of reproductive processes in Abies sibirica Ledeb. to changing environment, the phenology of the development of the species male reproductive cones at introduction was studied. Phenological shift in Abies sibirica meiosis and pollination was observed. An earlier start of male bud reproductive development is founded in V.N. Sukachev Institute of Forest Arboretum resulted in increasing meiosis and pollen irregularities. Insufficient high quality pollen in the species at its pollination stage may be a major factor responsible for the incapability to produce the viable seeds in quantities sufficient for pollination in seed gardens. Responses of the fir male cone development to the current environmental conditions at the Arboretum may be considered as a model of adaptation of the species to climatic changes.
