In the research, four shading treatments were set, including the treatments with shading degrees at 0, 40%, 60% and 70%, in order to explore storage rate and seedling growth of annual Phoebe bournei. The results showe...In the research, four shading treatments were set, including the treatments with shading degrees at 0, 40%, 60% and 70%, in order to explore storage rate and seedling growth of annual Phoebe bournei. The results showed that the storage rate is growing upon shading degree. In the research, for example, storage rate reached the peak with the shading degree at 70%, and only 42.2% with shading degree at 0. In addition, seedling height and ground diameter showed extremely significant differences among treatments, and the treatment with shading degree at 60% was the best.展开更多
ln order to discuss the optimum seedling density of Toona ciliate, different seedling densities were studied. The results showed that seeding height and basal diameter decreased and quality of the seedlings declined w...ln order to discuss the optimum seedling density of Toona ciliate, different seedling densities were studied. The results showed that seeding height and basal diameter decreased and quality of the seedlings declined with the increase of seedling density. The reasonable density of seedlings is key to cultivate high-quality seedlings and achieve the best seedling efficiency. The optimum density was 30 plants/m2 for the first class seedlings of biennial seedlings, and the optimum density of l and ll seedlings for production afforestation was 40 plants/m2.展开更多
The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on aut...The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.展开更多
The stimulative effect of trace elements on seed germination and seedling growth of Pinus tabulaeformis was tested. The experiments were carried out on seed soak and topdressing with different trace elements and varie...The stimulative effect of trace elements on seed germination and seedling growth of Pinus tabulaeformis was tested. The experiments were carried out on seed soak and topdressing with different trace elements and varied concentrations at the nursery of Gardens Research Institute, Harbin, in 2000-2001. The experimental results showed that soaking seed with 1% and 0.2% concentrations of Mn element produced best result for seed germination, and the germination rate was increased by 9%~19% for the seeds treated with 1% concentration and 12%~14% for the seeds treated with 0.2% concentration compared with the control group. The seeds treated with boron element had lowest germination rate. For trace element topdressing, Mn and Mo elements presented good result for seedling growth and the treatment with low concentration was even better. The height or chlorophyll content of the seedlings with spray of low-concentration Mn and Mo element was much higher than that of untreated ones. In the contrast to the treating method of seed soak, topdressing (application of spraying on foliage) had evident effect on seedling growth.展开更多
Effects of water and heat stress treatments on chlorophyll fluorescence of Chinese fir (Cunninghamia lanceolata), Masson pine (Pinus massoniana) and western redcedar (Thuja plicata D. Don)_seedlings were monitored dur...Effects of water and heat stress treatments on chlorophyll fluorescence of Chinese fir (Cunninghamia lanceolata), Masson pine (Pinus massoniana) and western redcedar (Thuja plicata D. Don)_seedlings were monitored during a three-cycle stress period. It was shown that ratio of variable to maximal chlorophyll fluorescence (Fv/Fm) of these three species responded differently to water stress treatments. The Fv/Fm ratio of western redcedar decreased dramatically after water stress, while that of Chinese fir had only a slight reduction and that of Masson pine had no significant change. The experiment also showed that the Fv/Fm ratio of all three species differed significantly under heat stress treatments. Concerning three different water plus heat stress cycles, it was found that the Fv/Fm ratios of Chinese fir and Masson pine measured at the end of each water plus heat stress cycle were not significantly different. However, the Fv/Fm ratio of western redcedar was diminished significantly in response to an increase of stress time. Keywords Chinese fir - Chlorophyll fluorescence - Heat stress - Masson pine - Water stress - Western redcedar CLC number Q945.17 - S791.248 Document code A Biography: Yu Fang-yuan (1965-), male, Ph. Doctor. Associate professor in College of Forest Resources and Environment, Nanjing, Forestry University, Nanjing 210037, P. R. China.Responsible editor: Zhu Hong展开更多
In order to improve the survival rate of planting seedlings of Phoebe zhen-nan, the grading standard for one-year-old container seedlings of Phoebe zhennan was developed by using cluster analysis. The results showed t...In order to improve the survival rate of planting seedlings of Phoebe zhen-nan, the grading standard for one-year-old container seedlings of Phoebe zhennan was developed by using cluster analysis. The results showed that the quality of Phoebe zhennan container seedlings could be estimated from seedling height and ground diameter. The Phoebe zhennan container seedlings were divided into 3 grades: Grade 1 (seedling height ≥ 38 cm; ground diameter ≥ 0.65 cm), Grade 2 (31.7 cm ≤ seedling height 〈 38 cm; 0.56 cm ≤ ground diameter 〈 0.65 cm) and Grade 3 (seedling height 〈 31.7 cm; ground diameter 〈 0.56 cm).展开更多
[Objective] The aim was to explore the effects of different factors on rapid propagation and seedling survival of Lonicera japonica Thunb. [Method] The cuttings of 1, 2 or 3 years old, with different length, were soak...[Objective] The aim was to explore the effects of different factors on rapid propagation and seedling survival of Lonicera japonica Thunb. [Method] The cuttings of 1, 2 or 3 years old, with different length, were soaked in different hormones at different concentrations for different time and planted at different dates. Finally, their rooting rate and survival rate in different treatments were measured and compared. [Result] The rooting rate and survival rate of one-year old cuttings with length of 10-13 cm and planted on September 20 and October 20, 2012 were relatively higher among all the treatments. Hormone treatment could significantly promote the callus formation and accelerate the rooting of the cuttings, and improve their survival rate. The cuttings treated with 120-200 mg/L ABT1 or NAA for 35-45 min had higher rooting rate and survival rate. Among them, the survival rate of cuttings treated with 160 mg/L ABT1 for 35 min was the highest, up to 92.5%. [Conclusion] The study provided basis for improving the survival rate of L. japonica by cuttage, and for optimizing the rapid propagation technique.展开更多
Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadlea...Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2.展开更多
[Objective] Breeding and genetic improvement for Cupressus funebris was performed based on the extensive genetic variation among provenances and fami- lies. [Method] The two-year-old Cupressus funebris, from 4 provena...[Objective] Breeding and genetic improvement for Cupressus funebris was performed based on the extensive genetic variation among provenances and fami- lies. [Method] The two-year-old Cupressus funebris, from 4 provenances and 34 superior Cupressus funebris families introduced from Chongqing and Qiandao Lake of Zhejiang Province, was used as test material, and the differences in growth traits among provenances and families at the seedling stage of Cupressus funebris were investigated. [Result] The height and ground diameter of seedlings differed signifi- cantly among provenances and families. Their variation coefficients among families were 11.37% and 18.89%, and among provenances were 7.25% and 12.58% re- spectively. [Conclusion] There was relatively rich genetic variation in height and ground diameter among provenances and families of Cupressus funebris. It has a certain breeding potential.展开更多
[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba (L) Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. ...[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba (L) Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. triloba seedlings had similar stem diameter and plant height and good growth vigour were taken as tested materials in 2005. 4 light gradient treatments which were the natural light with 100% light intensity, one-layer, two-layer and three-layer black shading network with the light transmittance rate of 50%, 25% and 12.5% were set up to study the effects of different shading treatments on growth of A. triloba. [ Result] With the shading treatments of one-layer and two-layer net, the plants of A. triloba seedlings grew rapidly. As the intensity of illumination decreased, the cetents of chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) and total chlorophyll increased at first and then reduced. At the same time the chlorophyll a/b value became smaller. Under natural light, the plants tended to consume more water and the soil temperature at 15:00 p. m was higher. There was a smaller difference among various treatments. [ Conclusion]The suitable shading treatment to the growth of A. triloba seedlings was under the light transmittance rate of 50% and height and stem diameter of trees increased fast. Chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) content in leaves of A. triloba seedlings were highest comparing with those in other conditions.展开更多
[Objective] This study aimed to solve the problems of low seed germina- tion rate and difficult bareroot seedling transplanting in artificial cultivation of Arto- carpus nanchuanensis, a native species in China. [Meth...[Objective] This study aimed to solve the problems of low seed germina- tion rate and difficult bareroot seedling transplanting in artificial cultivation of Arto- carpus nanchuanensis, a native species in China. [Method] Under different seed treatment and seedling style, the seed germination rate and seedling emergence rate of A. nanchuanensis were investigated. [Result] tn both sand bed and direct sowing yellow soil, the seed germination rate, seedling survival rate and seedling emergence rate in the treatment II were all higher than those in the treatments I and III. The average seed germination rate, seedling survival rate and seedling emergence rate in sand beds were 1.5%, 16.27% and 13.95%, respectively higher than those in direct sowing yellow soil. The average seedling emergence rate in sand beds was 2.46% higher than that in containers. Among the 8 kinds of light matrix formulas, the growth of seedlings in the formula VIII was best. In the three treatment groups, the seedling emergence rates, seedling heights and ground diame- ters in the formula VIII were all significantly different from those in the other formu- las. The seedling growth in the formula I and III ranked second, while the seedling emergence rate, seedling height and ground diameter in the formula VII were the poorest. [Conclusion] If conditions allow, the formulas I (meadow soil:vermiculite:yel- low soi1=5:3:2), III (meadow soil:perlite:yellow soi1=5:3:2) and VIII (peat:forest top soi1=6:4) should be promoted in seedling with light matrixes.展开更多
Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided ...Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided into five subplots) respectively based on the altitudinal gradient, stand density, slope location, and slope aspect to investigate the effects of environmental factors on tree seedling regeneration in a pine-oak mixed forest. The results indicated that the seedling density was significantly higher at altitudes of 1,283 m to 1,665 m, whereas the sapling density did not differ with altitudes. The seedling and sapling density decreased significantly at 1,835 m. The seedling densities on the upper slopes were much higher than those on the middle and lower slopes, whereas the sapling density had no difference. The sapling density decreased southwest (20°-75°) whereas gradually from the it increased on the shady slopes to the northeast (40°). The seedling density increased from southwest (20°) to northeast (40°The seedling and sapling densities increased with the stand density (850 trees ha-1 to 1,525 trees ha-1) whereas the sapling density was significantly lower in stands (1,9oo trees ha-O. Principal components analysis showed that the slope aspect and stand density had more important roles in tree regeneration in this study region compared with the other two factors. Therefore, our findings suggest that it will be beneficial to keep stands at a moderate density on shady slopes. Appropriate thinning of higher density stands is also expected to promote the natural regeneration of pine-oak mixed forest.展开更多
[Objective] This study aimed to study the seedling nursery and afforesta- tion of Liriodendron chinense (Hemsl.).Sarg. in northern Guangxi Province, thereby providing theoretical basis for the extension of L. chinen...[Objective] This study aimed to study the seedling nursery and afforesta- tion of Liriodendron chinense (Hemsl.).Sarg. in northern Guangxi Province, thereby providing theoretical basis for the extension of L. chinense in this region. [Method] The growth situation of L. chinense seedlings and soil fertility in northern Guangxi Province were investigated. [Result] The L. chinense seedlings in northern Guangxi Province showed significant changes during the growth period. Among the three- year-old L. chinense plants, the average plant height reached as high as 331.11 cm, the average ground diameter was 5.05 cm, and the average crown diameter was 122.22 cm. After three years' afforestation with one-year-old seedlings, the av- erage plant height of L. chinense was 357.20 cm, the average ground diameter was 6.53 cm, and the average crown diameter was 170.43 cm. The detection results of soil fertility were as follows: the soil was strongly acidic; the organic matter and to- tal phosphorus contents were moderate; and the total potassium content was rela- tively abundant. [Conclusion] L. chinense grows rapidly in northern Guangxi Province of China, and is suitable for extension in this area.展开更多
One-year-old seedlings of Dalbergia sissoo from a single provenance were planted in non-weighing lysimeter tanks in July 1998 with a view to provide optimize irrigation parameters in desert areas. Varying water regime...One-year-old seedlings of Dalbergia sissoo from a single provenance were planted in non-weighing lysimeter tanks in July 1998 with a view to provide optimize irrigation parameters in desert areas. Varying water regimes were maintained by re-irrigating the seedlings at 36.2 mm (W1), 26.5 mm (W2), 20.2 mm (W3) and 18.1 mm (W4) treatments when the soil water content decreased to 7.56%, 5.79%, 4.44%, 3.23% in the respective treatments. Height, collar diameter, number of leaves and leaf area were highest (p 〈 0.01) for the seedlings irrigated at W1 levek Above-mentioned growth parameters did not differ between W1 and W2 treatments but the seedlings in W2 level had highest biomass per liter of water use (i.e., water use efficiency, WUE). Irrigation levels of W3 to W5 negatively affected seedling growth, biomass production and nutrient accumulation. Soil water availability below W2 level (i.e., 5.79%) caused an increase in percentage of root biomass to the total biomass of the seedling. However, there was a decrease in percentage of leaf dry biomass in W3 and W4 treatments and in percentage of stem dry biomass in the seedlings of W5 treatment. Seedlings in W5 treatment survived till at soil water potential of-1.96 MPa. Limitation of soil water availability in W3 and W4 treatments affected growth and biomass production of D. sissoo seedlings. W: level was best for growth and biomass production in which water use efficiency was highest. Therefore, better growth and biomass production of D. sissoo seedlings could be obtained by irrigating the seedlings at soil water content of≥5.79% in the loamy sand soil.展开更多
Microbial Inoculants as Effective Microorganisms (EM) were applied to find out their effects on germination and seedling growth of Albizia saman in the nursery. The seedlings were grown in a mixture of sandy soils a...Microbial Inoculants as Effective Microorganisms (EM) were applied to find out their effects on germination and seedling growth of Albizia saman in the nursery. The seedlings were grown in a mixture of sandy soils and cow dung (3:1) kept in polybags. The EM solution at different concentrations (0.1%, 0.5%, 1%, 2%, 5% and 10%) was incorporated before and after a week of sowing seeds. Germination and physical growth parameters, including shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total biomass increment over the control were measured. The nodulation status influenced by EM was also observed along with the estimation of chemical parameters like chlorophyll a, chlorophyll b and carotenoid. Both germination and the measured physical growth parameters were found significantly (P〈0.05) higher in seedlings treated with different concentrations of EM solution in comparison to the control. Maximum growth was found at 2% followed by 1% EM solution. Nodulation was higher at 0.1% concentration but it normally decreased with the increase of concentrations. Although there were a higher amount of pigments in leaves of the treated seedlings than of the control, the variations recorded with respect to chlorophyll a, b and carotenoid were not significantly higher in most of the treatments. Treated seedlings showed variable results along with the increment of EM applications and most of the parameters showed best results at the medium range of concentrations. The study indicates that the Microbial Inoculant (EM) technology might be useful to improve the growth of seedlings in the nursery. This also indicates that the associated beneficial organisms along with the polybag soils might be of value in improving the degraded soil or poor field soil for better nutrient and water uptake during the initial growth of transplanted seedlings.展开更多
After exposure of one-year old seedlings of Swietenia macrophylla to an overnight temperature (13 C, 19 C, 25 C, 31 C or 35 C), the leaf net photosynthetic rate (Pn) was researched through measuring photosynthetic lig...After exposure of one-year old seedlings of Swietenia macrophylla to an overnight temperature (13 C, 19 C, 25 C, 31 C or 35 C), the leaf net photosynthetic rate (Pn) was researched through measuring photosynthetic light-response curves at 360 mmolmol-1 CO2, and photosynthetic CO2-response curves at light-saturated intensity (1500 mmolm-2 s-1). The optimal temperature for photosynthesis measured at 360 mmol穖ol-1 CO2 was from 25 C to 31 C, but which was from 31C to 35 C at saturating CO2 concentration. At temperature of below 25 C, the decline in Pn was mainly due to the drop in carboxylation efficiency (Ce), while as temperature was over 31 C, the reduction in Pn resulted from both decrease in Ce and increase in leaf respiration. The CO2-induced stimulation of photosynthesis was strongly inhibited at temperatures below 13 C. The results showed that, the leaf photosynthesis of tropical evergreen plants should not be accelerated at low temperature in winter season with elevated CO2 concentration in the future.展开更多
基金Supported by Forestry Science and Technology Project of Hunan Province(XLK201406)~~
文摘In the research, four shading treatments were set, including the treatments with shading degrees at 0, 40%, 60% and 70%, in order to explore storage rate and seedling growth of annual Phoebe bournei. The results showed that the storage rate is growing upon shading degree. In the research, for example, storage rate reached the peak with the shading degree at 70%, and only 42.2% with shading degree at 0. In addition, seedling height and ground diameter showed extremely significant differences among treatments, and the treatment with shading degree at 60% was the best.
基金Supported by Forestry Science and Technology Planning Program(XLK201406)~~
文摘ln order to discuss the optimum seedling density of Toona ciliate, different seedling densities were studied. The results showed that seeding height and basal diameter decreased and quality of the seedlings declined with the increase of seedling density. The reasonable density of seedlings is key to cultivate high-quality seedlings and achieve the best seedling efficiency. The optimum density was 30 plants/m2 for the first class seedlings of biennial seedlings, and the optimum density of l and ll seedlings for production afforestation was 40 plants/m2.
基金This paper was supported by National Natural Science Foundation of China (Grant No. 39670607).
文摘The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.
文摘The stimulative effect of trace elements on seed germination and seedling growth of Pinus tabulaeformis was tested. The experiments were carried out on seed soak and topdressing with different trace elements and varied concentrations at the nursery of Gardens Research Institute, Harbin, in 2000-2001. The experimental results showed that soaking seed with 1% and 0.2% concentrations of Mn element produced best result for seed germination, and the germination rate was increased by 9%~19% for the seeds treated with 1% concentration and 12%~14% for the seeds treated with 0.2% concentration compared with the control group. The seeds treated with boron element had lowest germination rate. For trace element topdressing, Mn and Mo elements presented good result for seedling growth and the treatment with low concentration was even better. The height or chlorophyll content of the seedlings with spray of low-concentration Mn and Mo element was much higher than that of untreated ones. In the contrast to the treating method of seed soak, topdressing (application of spraying on foliage) had evident effect on seedling growth.
文摘Effects of water and heat stress treatments on chlorophyll fluorescence of Chinese fir (Cunninghamia lanceolata), Masson pine (Pinus massoniana) and western redcedar (Thuja plicata D. Don)_seedlings were monitored during a three-cycle stress period. It was shown that ratio of variable to maximal chlorophyll fluorescence (Fv/Fm) of these three species responded differently to water stress treatments. The Fv/Fm ratio of western redcedar decreased dramatically after water stress, while that of Chinese fir had only a slight reduction and that of Masson pine had no significant change. The experiment also showed that the Fv/Fm ratio of all three species differed significantly under heat stress treatments. Concerning three different water plus heat stress cycles, it was found that the Fv/Fm ratios of Chinese fir and Masson pine measured at the end of each water plus heat stress cycle were not significantly different. However, the Fv/Fm ratio of western redcedar was diminished significantly in response to an increase of stress time. Keywords Chinese fir - Chlorophyll fluorescence - Heat stress - Masson pine - Water stress - Western redcedar CLC number Q945.17 - S791.248 Document code A Biography: Yu Fang-yuan (1965-), male, Ph. Doctor. Associate professor in College of Forest Resources and Environment, Nanjing, Forestry University, Nanjing 210037, P. R. China.Responsible editor: Zhu Hong
基金Supported by Forestry Science and Technology Program of Hunan Province(2010-06)~~
文摘In order to improve the survival rate of planting seedlings of Phoebe zhen-nan, the grading standard for one-year-old container seedlings of Phoebe zhennan was developed by using cluster analysis. The results showed that the quality of Phoebe zhennan container seedlings could be estimated from seedling height and ground diameter. The Phoebe zhennan container seedlings were divided into 3 grades: Grade 1 (seedling height ≥ 38 cm; ground diameter ≥ 0.65 cm), Grade 2 (31.7 cm ≤ seedling height 〈 38 cm; 0.56 cm ≤ ground diameter 〈 0.65 cm) and Grade 3 (seedling height 〈 31.7 cm; ground diameter 〈 0.56 cm).
基金Supported by the Science and Technology Program of Loudi City(3331118)the Science and Technology Program of Hunan Province(2011FJ3039)~~
文摘[Objective] The aim was to explore the effects of different factors on rapid propagation and seedling survival of Lonicera japonica Thunb. [Method] The cuttings of 1, 2 or 3 years old, with different length, were soaked in different hormones at different concentrations for different time and planted at different dates. Finally, their rooting rate and survival rate in different treatments were measured and compared. [Result] The rooting rate and survival rate of one-year old cuttings with length of 10-13 cm and planted on September 20 and October 20, 2012 were relatively higher among all the treatments. Hormone treatment could significantly promote the callus formation and accelerate the rooting of the cuttings, and improve their survival rate. The cuttings treated with 120-200 mg/L ABT1 or NAA for 35-45 min had higher rooting rate and survival rate. Among them, the survival rate of cuttings treated with 160 mg/L ABT1 for 35 min was the highest, up to 92.5%. [Conclusion] The study provided basis for improving the survival rate of L. japonica by cuttage, and for optimizing the rapid propagation technique.
基金The project was supported by National Key Basic Development of China (G1999043400) and the grant KZCX-406-4 KZCX1SW01 of the Chinese Academy of Sciences
文摘Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2.
基金Supported by Key Science and Technology Program of ChongqingFoundation for Forest Tree Breeding in ChongqingNational Wildlife Conservation and Nature Reserve Construction Project~~
文摘[Objective] Breeding and genetic improvement for Cupressus funebris was performed based on the extensive genetic variation among provenances and fami- lies. [Method] The two-year-old Cupressus funebris, from 4 provenances and 34 superior Cupressus funebris families introduced from Chongqing and Qiandao Lake of Zhejiang Province, was used as test material, and the differences in growth traits among provenances and families at the seedling stage of Cupressus funebris were investigated. [Result] The height and ground diameter of seedlings differed signifi- cantly among provenances and families. Their variation coefficients among families were 11.37% and 18.89%, and among provenances were 7.25% and 12.58% re- spectively. [Conclusion] There was relatively rich genetic variation in height and ground diameter among provenances and families of Cupressus funebris. It has a certain breeding potential.
基金Supported by the National"948"Import Program(2001-46)~~
文摘[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba (L) Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. triloba seedlings had similar stem diameter and plant height and good growth vigour were taken as tested materials in 2005. 4 light gradient treatments which were the natural light with 100% light intensity, one-layer, two-layer and three-layer black shading network with the light transmittance rate of 50%, 25% and 12.5% were set up to study the effects of different shading treatments on growth of A. triloba. [ Result] With the shading treatments of one-layer and two-layer net, the plants of A. triloba seedlings grew rapidly. As the intensity of illumination decreased, the cetents of chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) and total chlorophyll increased at first and then reduced. At the same time the chlorophyll a/b value became smaller. Under natural light, the plants tended to consume more water and the soil temperature at 15:00 p. m was higher. There was a smaller difference among various treatments. [ Conclusion]The suitable shading treatment to the growth of A. triloba seedlings was under the light transmittance rate of 50% and height and stem diameter of trees increased fast. Chlorophyll a ( Chl. a), chlorophyll b ( Chl. b) content in leaves of A. triloba seedlings were highest comparing with those in other conditions.
基金Supported by Wildlife Conservation and Nature Reserve Construction Projects of Chongqing City in 2013~~
文摘[Objective] This study aimed to solve the problems of low seed germina- tion rate and difficult bareroot seedling transplanting in artificial cultivation of Arto- carpus nanchuanensis, a native species in China. [Method] Under different seed treatment and seedling style, the seed germination rate and seedling emergence rate of A. nanchuanensis were investigated. [Result] tn both sand bed and direct sowing yellow soil, the seed germination rate, seedling survival rate and seedling emergence rate in the treatment II were all higher than those in the treatments I and III. The average seed germination rate, seedling survival rate and seedling emergence rate in sand beds were 1.5%, 16.27% and 13.95%, respectively higher than those in direct sowing yellow soil. The average seedling emergence rate in sand beds was 2.46% higher than that in containers. Among the 8 kinds of light matrix formulas, the growth of seedlings in the formula VIII was best. In the three treatment groups, the seedling emergence rates, seedling heights and ground diame- ters in the formula VIII were all significantly different from those in the other formu- las. The seedling growth in the formula I and III ranked second, while the seedling emergence rate, seedling height and ground diameter in the formula VII were the poorest. [Conclusion] If conditions allow, the formulas I (meadow soil:vermiculite:yel- low soi1=5:3:2), III (meadow soil:perlite:yellow soi1=5:3:2) and VIII (peat:forest top soi1=6:4) should be promoted in seedling with light matrixes.
基金funded by the Special Research Program for Public-Welfare Forestry of State Forestry Administration of China (Grant No. 20100400206)National Natural Science Funds of China (Grant No. 31070570)CFERN & GENE Award Funds on Ecological Paper
文摘Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided into five subplots) respectively based on the altitudinal gradient, stand density, slope location, and slope aspect to investigate the effects of environmental factors on tree seedling regeneration in a pine-oak mixed forest. The results indicated that the seedling density was significantly higher at altitudes of 1,283 m to 1,665 m, whereas the sapling density did not differ with altitudes. The seedling and sapling density decreased significantly at 1,835 m. The seedling densities on the upper slopes were much higher than those on the middle and lower slopes, whereas the sapling density had no difference. The sapling density decreased southwest (20°-75°) whereas gradually from the it increased on the shady slopes to the northeast (40°). The seedling density increased from southwest (20°) to northeast (40°The seedling and sapling densities increased with the stand density (850 trees ha-1 to 1,525 trees ha-1) whereas the sapling density was significantly lower in stands (1,9oo trees ha-O. Principal components analysis showed that the slope aspect and stand density had more important roles in tree regeneration in this study region compared with the other two factors. Therefore, our findings suggest that it will be beneficial to keep stands at a moderate density on shady slopes. Appropriate thinning of higher density stands is also expected to promote the natural regeneration of pine-oak mixed forest.
基金Supported by Forestry Science and Technology Program of Guangxi Province[GLK(2015)26]Science and Technology Achievement Transformation and Application Fund of Guilin City(20140124-2)
文摘[Objective] This study aimed to study the seedling nursery and afforesta- tion of Liriodendron chinense (Hemsl.).Sarg. in northern Guangxi Province, thereby providing theoretical basis for the extension of L. chinense in this region. [Method] The growth situation of L. chinense seedlings and soil fertility in northern Guangxi Province were investigated. [Result] The L. chinense seedlings in northern Guangxi Province showed significant changes during the growth period. Among the three- year-old L. chinense plants, the average plant height reached as high as 331.11 cm, the average ground diameter was 5.05 cm, and the average crown diameter was 122.22 cm. After three years' afforestation with one-year-old seedlings, the av- erage plant height of L. chinense was 357.20 cm, the average ground diameter was 6.53 cm, and the average crown diameter was 170.43 cm. The detection results of soil fertility were as follows: the soil was strongly acidic; the organic matter and to- tal phosphorus contents were moderate; and the total potassium content was rela- tively abundant. [Conclusion] L. chinense grows rapidly in northern Guangxi Province of China, and is suitable for extension in this area.
文摘One-year-old seedlings of Dalbergia sissoo from a single provenance were planted in non-weighing lysimeter tanks in July 1998 with a view to provide optimize irrigation parameters in desert areas. Varying water regimes were maintained by re-irrigating the seedlings at 36.2 mm (W1), 26.5 mm (W2), 20.2 mm (W3) and 18.1 mm (W4) treatments when the soil water content decreased to 7.56%, 5.79%, 4.44%, 3.23% in the respective treatments. Height, collar diameter, number of leaves and leaf area were highest (p 〈 0.01) for the seedlings irrigated at W1 levek Above-mentioned growth parameters did not differ between W1 and W2 treatments but the seedlings in W2 level had highest biomass per liter of water use (i.e., water use efficiency, WUE). Irrigation levels of W3 to W5 negatively affected seedling growth, biomass production and nutrient accumulation. Soil water availability below W2 level (i.e., 5.79%) caused an increase in percentage of root biomass to the total biomass of the seedling. However, there was a decrease in percentage of leaf dry biomass in W3 and W4 treatments and in percentage of stem dry biomass in the seedlings of W5 treatment. Seedlings in W5 treatment survived till at soil water potential of-1.96 MPa. Limitation of soil water availability in W3 and W4 treatments affected growth and biomass production of D. sissoo seedlings. W: level was best for growth and biomass production in which water use efficiency was highest. Therefore, better growth and biomass production of D. sissoo seedlings could be obtained by irrigating the seedlings at soil water content of≥5.79% in the loamy sand soil.
文摘Microbial Inoculants as Effective Microorganisms (EM) were applied to find out their effects on germination and seedling growth of Albizia saman in the nursery. The seedlings were grown in a mixture of sandy soils and cow dung (3:1) kept in polybags. The EM solution at different concentrations (0.1%, 0.5%, 1%, 2%, 5% and 10%) was incorporated before and after a week of sowing seeds. Germination and physical growth parameters, including shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total biomass increment over the control were measured. The nodulation status influenced by EM was also observed along with the estimation of chemical parameters like chlorophyll a, chlorophyll b and carotenoid. Both germination and the measured physical growth parameters were found significantly (P〈0.05) higher in seedlings treated with different concentrations of EM solution in comparison to the control. Maximum growth was found at 2% followed by 1% EM solution. Nodulation was higher at 0.1% concentration but it normally decreased with the increase of concentrations. Although there were a higher amount of pigments in leaves of the treated seedlings than of the control, the variations recorded with respect to chlorophyll a, b and carotenoid were not significantly higher in most of the treatments. Treated seedlings showed variable results along with the increment of EM applications and most of the parameters showed best results at the medium range of concentrations. The study indicates that the Microbial Inoculant (EM) technology might be useful to improve the growth of seedlings in the nursery. This also indicates that the associated beneficial organisms along with the polybag soils might be of value in improving the degraded soil or poor field soil for better nutrient and water uptake during the initial growth of transplanted seedlings.
文摘After exposure of one-year old seedlings of Swietenia macrophylla to an overnight temperature (13 C, 19 C, 25 C, 31 C or 35 C), the leaf net photosynthetic rate (Pn) was researched through measuring photosynthetic light-response curves at 360 mmolmol-1 CO2, and photosynthetic CO2-response curves at light-saturated intensity (1500 mmolm-2 s-1). The optimal temperature for photosynthesis measured at 360 mmol穖ol-1 CO2 was from 25 C to 31 C, but which was from 31C to 35 C at saturating CO2 concentration. At temperature of below 25 C, the decline in Pn was mainly due to the drop in carboxylation efficiency (Ce), while as temperature was over 31 C, the reduction in Pn resulted from both decrease in Ce and increase in leaf respiration. The CO2-induced stimulation of photosynthesis was strongly inhibited at temperatures below 13 C. The results showed that, the leaf photosynthesis of tropical evergreen plants should not be accelerated at low temperature in winter season with elevated CO2 concentration in the future.