One-year-old seedlings of Amur maple (Acer ginnala Maxim), Ussurian pear (Pyrus ussuriensis Maxim) and David peach (Prunus davidiana Carr) were planted in pots in greenhouse and treated with four different soil moistu...One-year-old seedlings of Amur maple (Acer ginnala Maxim), Ussurian pear (Pyrus ussuriensis Maxim) and David peach (Prunus davidiana Carr) were planted in pots in greenhouse and treated with four different soil moisture contents (75.0%, 61.1%, 46.4% and 35.4%). The results showed that net photosynthesis rate (NPR), transpiration rate (TR) and stomatal conductance (Sc) of seedlings of the three species decreased with the decease of soil moisture content, and Amur maple seedlings had the greatest change in those physiological indices, followed by Ussurian pear, David peach. Amur maple and Ussurian pear seedlings also presented a decrease tendency in water use efficiency (WUE) under lower soil moisture content, whereas this was reversed for David peach. Under water stress the biomass allocation to seedling root had a significant increase for all the experimental species. As to root/shoot ratio, Amur maple seedlings had the biggest increase, while David peach had the smallest increase. The leaf plasticity of Amur maple seedlings was greater, the leaf size and total leaf area decreased significantly as the stress was intensified. No significant change of leaf size and total leaf area was found in seedlings of Ussurian pear and David peach. It was concluded that Amur maple was more tolerant to soil moisture stress in comparison with David peach and Ussurian pear.展开更多
We investigated wood anatomical changes due to uptake and accumulation of cadmium and lead from contaminated soils in Acer velutinum Boiss seedlings. Two-year old seedlings were exposed for 180 days to soil concentrat...We investigated wood anatomical changes due to uptake and accumulation of cadmium and lead from contaminated soils in Acer velutinum Boiss seedlings. Two-year old seedlings were exposed for 180 days to soil concentrations with varying cadmium and lead concentra- tions. We measured three wood anatomical traits, average vessel area （gm2）, vessel number per square millimetre, and vessel lumen area per- centage （%）. For assessing the cadmium and lead accumulation, we measured the concentrations in the soil, leaf, stem, and root. Average vessel area and vessel lumen area percentage were similar （p〉0.05） in control and treated seedlings. Vessel number per square millimetre showed a decreasing trend from pith to bark in control and treated seed- lings, and the trend was more pronounced in treated seedlings. We con- clude that vessel number per square millimetre in A. velutinum is influ- enced by soil contamination. A. velutinum Boiss is not a suitable species for remediation of soils contaminated by cadmium and lead but it can be used as an indicator of the soil lead contamination, because lead concentrations in seedlings increased with increasing amount of lead in the soil.展开更多
It has become necessary to develop stands of fast growing endemic species in the Caspian forests because of their reduction in area and the domestic demand of timber processing industries in Iran. Acer velutinum, an e...It has become necessary to develop stands of fast growing endemic species in the Caspian forests because of their reduction in area and the domestic demand of timber processing industries in Iran. Acer velutinum, an endemic species in Iran, is often planted in monocultures or in a mixture with other endemic species. Our study was conducted on A. velutinum planted in Berenjestanak(control plots) and Chaibagh(thinned plots) in northern Iran in 1991. A randomized sampling method with circular sampling plots of 100 m2was used to measure diameter and height of trees. The results show that the diameter of trees in thinned stands was 19.98 cm and in the control stands 13.84 cm, while the mean heights were 18.33 and 17.46 m, respectively. The mean basal area in thinned stands was 30.74 m2and in the control 15.70 m2per ha. The results of Student’s t tests indicate that there are significant differences at a probability level of 99.9% between the two variously treated stands in diameter(d), height(h), basal area, volume growth and the stability coefficient. We conclude that tending operations with suitable intensity in different time periods are recommended to obtain stable stands.展开更多
In our investigation we studied fiber lengths and the transition age from juvenile to mature wood in Acer velutinum Boiss. For this purpose, samples from three normal maple trees at a Noshahr site in northern Iran wer...In our investigation we studied fiber lengths and the transition age from juvenile to mature wood in Acer velutinum Boiss. For this purpose, samples from three normal maple trees at a Noshahr site in northern Iran were selected. Disks were cut at breast height. Test samples were taken along a radial direction from the pith to the bark, accounting for every ring during a 48-year period. We used the Franklin method to distinguish between fibers of juvenile and mature wood. The results show that the fiber length in- creased along the radial direction from the pith to the bark. The transition age between juvenile and mature wood was determined at the 14th annual ring from the pith.展开更多
基金This study was supported by Science and Technology Program of Heilongjiang Province (GC01KB213), and the Quick Response of Basic Research Supporting Program (2001CCB00600)
文摘One-year-old seedlings of Amur maple (Acer ginnala Maxim), Ussurian pear (Pyrus ussuriensis Maxim) and David peach (Prunus davidiana Carr) were planted in pots in greenhouse and treated with four different soil moisture contents (75.0%, 61.1%, 46.4% and 35.4%). The results showed that net photosynthesis rate (NPR), transpiration rate (TR) and stomatal conductance (Sc) of seedlings of the three species decreased with the decease of soil moisture content, and Amur maple seedlings had the greatest change in those physiological indices, followed by Ussurian pear, David peach. Amur maple and Ussurian pear seedlings also presented a decrease tendency in water use efficiency (WUE) under lower soil moisture content, whereas this was reversed for David peach. Under water stress the biomass allocation to seedling root had a significant increase for all the experimental species. As to root/shoot ratio, Amur maple seedlings had the biggest increase, while David peach had the smallest increase. The leaf plasticity of Amur maple seedlings was greater, the leaf size and total leaf area decreased significantly as the stress was intensified. No significant change of leaf size and total leaf area was found in seedlings of Ussurian pear and David peach. It was concluded that Amur maple was more tolerant to soil moisture stress in comparison with David peach and Ussurian pear.
文摘We investigated wood anatomical changes due to uptake and accumulation of cadmium and lead from contaminated soils in Acer velutinum Boiss seedlings. Two-year old seedlings were exposed for 180 days to soil concentrations with varying cadmium and lead concentra- tions. We measured three wood anatomical traits, average vessel area （gm2）, vessel number per square millimetre, and vessel lumen area per- centage （%）. For assessing the cadmium and lead accumulation, we measured the concentrations in the soil, leaf, stem, and root. Average vessel area and vessel lumen area percentage were similar （p〉0.05） in control and treated seedlings. Vessel number per square millimetre showed a decreasing trend from pith to bark in control and treated seed- lings, and the trend was more pronounced in treated seedlings. We con- clude that vessel number per square millimetre in A. velutinum is influ- enced by soil contamination. A. velutinum Boiss is not a suitable species for remediation of soils contaminated by cadmium and lead but it can be used as an indicator of the soil lead contamination, because lead concentrations in seedlings increased with increasing amount of lead in the soil.
文摘It has become necessary to develop stands of fast growing endemic species in the Caspian forests because of their reduction in area and the domestic demand of timber processing industries in Iran. Acer velutinum, an endemic species in Iran, is often planted in monocultures or in a mixture with other endemic species. Our study was conducted on A. velutinum planted in Berenjestanak(control plots) and Chaibagh(thinned plots) in northern Iran in 1991. A randomized sampling method with circular sampling plots of 100 m2was used to measure diameter and height of trees. The results show that the diameter of trees in thinned stands was 19.98 cm and in the control stands 13.84 cm, while the mean heights were 18.33 and 17.46 m, respectively. The mean basal area in thinned stands was 30.74 m2and in the control 15.70 m2per ha. The results of Student’s t tests indicate that there are significant differences at a probability level of 99.9% between the two variously treated stands in diameter(d), height(h), basal area, volume growth and the stability coefficient. We conclude that tending operations with suitable intensity in different time periods are recommended to obtain stable stands.
文摘In our investigation we studied fiber lengths and the transition age from juvenile to mature wood in Acer velutinum Boiss. For this purpose, samples from three normal maple trees at a Noshahr site in northern Iran were selected. Disks were cut at breast height. Test samples were taken along a radial direction from the pith to the bark, accounting for every ring during a 48-year period. We used the Franklin method to distinguish between fibers of juvenile and mature wood. The results show that the fiber length in- creased along the radial direction from the pith to the bark. The transition age between juvenile and mature wood was determined at the 14th annual ring from the pith.
