1993 Vol. 6, No. 5
Display Method:
1993, 6(5): 473-479.
[Abstract]
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Abstract:
The average amount of the present remaining litter in the forest community of the Eastern Yanshan Mountain is 4.35~28.67t/ha, with the greatest amount in the mixed forests of aspen (Populus davidiana Dode) with other broadleaf trees, the mixed forests of Chinese pine (Pinus tablaeformis Carr.) with oak, and the mixed forests of linden with other broadleaf trees; with the greater amount in the oak (Quercus variabilis B1., Q. liaotungensis Koidz., Q. dentata Thunb.) and Chinese arborvitae (Platy-cladus orientalis (L.) Endl.) forests. The average amount of the present remaining litters in the shrub community is 4.15~18.94t/ha, smaller than that in the forest community. The amount of the present remaining litters in the forests is determined by the composition of tree species, age of the forests, site condition and human interferences. Human interferences have brought about almost a complete loss of the litters. The total amount of the nutrient elements in the forest litters is 0.176~1.534 t/ha, and the maximum water content in the forest litter is 3.9-54.0 t/ha, averaging 41.2 t/ha. The total amount of the nutrient elements in the shrub litter is 0.327-0.846 t/ha, and the maximum water content in the shrub litter is 4.8-26.9 t/ha, averaging 16.2t/ha.
The average amount of the present remaining litter in the forest community of the Eastern Yanshan Mountain is 4.35~28.67t/ha, with the greatest amount in the mixed forests of aspen (Populus davidiana Dode) with other broadleaf trees, the mixed forests of Chinese pine (Pinus tablaeformis Carr.) with oak, and the mixed forests of linden with other broadleaf trees; with the greater amount in the oak (Quercus variabilis B1., Q. liaotungensis Koidz., Q. dentata Thunb.) and Chinese arborvitae (Platy-cladus orientalis (L.) Endl.) forests. The average amount of the present remaining litters in the shrub community is 4.15~18.94t/ha, smaller than that in the forest community. The amount of the present remaining litters in the forests is determined by the composition of tree species, age of the forests, site condition and human interferences. Human interferences have brought about almost a complete loss of the litters. The total amount of the nutrient elements in the forest litters is 0.176~1.534 t/ha, and the maximum water content in the forest litter is 3.9-54.0 t/ha, averaging 41.2 t/ha. The total amount of the nutrient elements in the shrub litter is 0.327-0.846 t/ha, and the maximum water content in the shrub litter is 4.8-26.9 t/ha, averaging 16.2t/ha.
1993, 6(5): 480-485.
Abstract:
Wetheartwood can be observed more or less in all living trees or logs of Populus deltoides I-69, in their various gorwth stages no matter how they planted; in Panjiawan,Jiayu County, Hubei Province. The percentage of wetheartwood of a tree is relevant to the water content of soil, but not to the planting method or the growth rate of the tree. The occurrence and discolouration of wetheartwood may be caused by bacteria activity. Five species of bacteria (Erwinia carotovora subsp. carotovora, E. rhapontioi (Millard) Burkhold, E. chrysanthemi Burkholder, Bacillus cereus Frankland, B. sphaericus Neidehave) have been isolated and identified. Observation of electron microscopy and the wood properties analysis indicated that the pit membranes of vessel-ray pits and the intervessel pits in wetheartwood were almost destroyed by bacteria. Comparing with the normal wood, the pH and acid buffering capacity, the content of extractives and ash are all higher, but the content of holo-cellulose and a-cellulose are a little lower. Besides, the specific gravity, shrinkage and mechnical properties of wetheartwood are lower than thos of normal wood. It is suggested that the approach of preventing the occurrence of wetheartwood should be further studied.
Wetheartwood can be observed more or less in all living trees or logs of Populus deltoides I-69, in their various gorwth stages no matter how they planted; in Panjiawan,Jiayu County, Hubei Province. The percentage of wetheartwood of a tree is relevant to the water content of soil, but not to the planting method or the growth rate of the tree. The occurrence and discolouration of wetheartwood may be caused by bacteria activity. Five species of bacteria (Erwinia carotovora subsp. carotovora, E. rhapontioi (Millard) Burkhold, E. chrysanthemi Burkholder, Bacillus cereus Frankland, B. sphaericus Neidehave) have been isolated and identified. Observation of electron microscopy and the wood properties analysis indicated that the pit membranes of vessel-ray pits and the intervessel pits in wetheartwood were almost destroyed by bacteria. Comparing with the normal wood, the pH and acid buffering capacity, the content of extractives and ash are all higher, but the content of holo-cellulose and a-cellulose are a little lower. Besides, the specific gravity, shrinkage and mechnical properties of wetheartwood are lower than thos of normal wood. It is suggested that the approach of preventing the occurrence of wetheartwood should be further studied.
1993, 6(5): 486-492.
Abstract:
This paper deals with tissue culture of three important commercial rattan species in China. The results show that the immature embryo is the best one of eight kinds of explants selected for rattan tissue culture. The embryoes cultured respectively in media RM5-1 and RM8-2 for 50 days were introduced into complete plantlets. Callus could be introduced from different explants shining 16 hours a day with 690 lx on the medium with salt concentration of 6899mg/L. RM6 is the super medium for introducing multiple shoots. It is estimated that 2.8×106 shoots can be obtained from one of the subcultured shoots a year. Microscopical observation on the multiple shoots shows that the distance between the nodes on a main shoot is very short, only 420 nm and the meristematic tissue of nodes can produce many axillary bud primordium while it is carrying out periclinal and anticlinal division. And the axillary bud primordium can be introduced into multiple shoots further. The meristematic cells of shoots from two years old seedlings can be rejuvenated by tissue culture, that is the cells, introduced by tissue culture, and have the following characters;smaller cell diameter, higher density and an enlarged nuclear.
This paper deals with tissue culture of three important commercial rattan species in China. The results show that the immature embryo is the best one of eight kinds of explants selected for rattan tissue culture. The embryoes cultured respectively in media RM5-1 and RM8-2 for 50 days were introduced into complete plantlets. Callus could be introduced from different explants shining 16 hours a day with 690 lx on the medium with salt concentration of 6899mg/L. RM6 is the super medium for introducing multiple shoots. It is estimated that 2.8×106 shoots can be obtained from one of the subcultured shoots a year. Microscopical observation on the multiple shoots shows that the distance between the nodes on a main shoot is very short, only 420 nm and the meristematic tissue of nodes can produce many axillary bud primordium while it is carrying out periclinal and anticlinal division. And the axillary bud primordium can be introduced into multiple shoots further. The meristematic cells of shoots from two years old seedlings can be rejuvenated by tissue culture, that is the cells, introduced by tissue culture, and have the following characters;smaller cell diameter, higher density and an enlarged nuclear.
1993, 6(5): 493-498.
Abstract:
Research on the propagation techniques of slash and loblolly pine by cuttings had been carried out for 3 years. The best propagation techniques are as follows;using medium size sand soil as medium,collecting the juvenile semi-woody cuttings, they were treated with rooting powder No.1 (low concentration) for slash pine and No.1 and No.2 (medium Concentration) for loblolly pine. The mist chamber should be used for raising rooting %. The rooting % may reach 95%. The height of 1-year old cuttings of slash and loblolly pine are 39~45cm with well developed root system. In comparison with the seedlings, the cost of the cutting is 2%~52% higher than that of the seedlings.
Research on the propagation techniques of slash and loblolly pine by cuttings had been carried out for 3 years. The best propagation techniques are as follows;using medium size sand soil as medium,collecting the juvenile semi-woody cuttings, they were treated with rooting powder No.1 (low concentration) for slash pine and No.1 and No.2 (medium Concentration) for loblolly pine. The mist chamber should be used for raising rooting %. The rooting % may reach 95%. The height of 1-year old cuttings of slash and loblolly pine are 39~45cm with well developed root system. In comparison with the seedlings, the cost of the cutting is 2%~52% higher than that of the seedlings.
1993, 6(5): 499-503.
Abstract:
This paper deals with climatic conditions in original lac-producing areas and lac insect introduction and cultivation in new places. Through more than a score of years' researches and popularizing efforts by lac scientists, the lac-growing zone has been extended from the south of 25° to 28° N and from 103° to 118° E. These new growing areas have been beyond the natural distribution range of lac insects in mountainous plateau. This result is of great significance for the study of entomological geography.
This paper deals with climatic conditions in original lac-producing areas and lac insect introduction and cultivation in new places. Through more than a score of years' researches and popularizing efforts by lac scientists, the lac-growing zone has been extended from the south of 25° to 28° N and from 103° to 118° E. These new growing areas have been beyond the natural distribution range of lac insects in mountainous plateau. This result is of great significance for the study of entomological geography.
1993, 6(5): 504-509.
Abstract:
There are mountain yellow brown soil, yellow soil,red yellow soil, yellow red soil and red soil was distributing from high altitude to low altitude in Nianzhu and Shangchun Forest Farms, in Dagang Mountain, Jiangxi Province. The soil organic matter decreases with the raise of elevation; available N increases from 17,63 to 25.20mg/100g, available Pincreases from 0.07 to 0.22mg/100g soil, while the change of available Kisn't clear. The activity of hydrogen peroxidase enzyme is similar to each other among different kinds of soils except the low activity in red soil. The polyphend oxidase enzyme activity is the lowest in yellow brown soil, which is 1/5 of the other types of soil, The amount of bacteria in soil over 480m above sea level is 27~300 times of that in red soil and yellow red soil below the elevation of 480 m respectively. The dominant population of actinomyces changes from grey hypha to white hypha, along with the occurence of branch bacilli-form bacteria as the elevation decline. Amount of fungi in yellow red soil and red soil occupies 12~15 percent of the total microorganism, but it is less than 1% among the other soil types. There is no obvious change in the fertility of different soil types above 325m. while the fertility of soil type below 325m decreases obviously
There are mountain yellow brown soil, yellow soil,red yellow soil, yellow red soil and red soil was distributing from high altitude to low altitude in Nianzhu and Shangchun Forest Farms, in Dagang Mountain, Jiangxi Province. The soil organic matter decreases with the raise of elevation; available N increases from 17,63 to 25.20mg/100g, available Pincreases from 0.07 to 0.22mg/100g soil, while the change of available Kisn't clear. The activity of hydrogen peroxidase enzyme is similar to each other among different kinds of soils except the low activity in red soil. The polyphend oxidase enzyme activity is the lowest in yellow brown soil, which is 1/5 of the other types of soil, The amount of bacteria in soil over 480m above sea level is 27~300 times of that in red soil and yellow red soil below the elevation of 480 m respectively. The dominant population of actinomyces changes from grey hypha to white hypha, along with the occurence of branch bacilli-form bacteria as the elevation decline. Amount of fungi in yellow red soil and red soil occupies 12~15 percent of the total microorganism, but it is less than 1% among the other soil types. There is no obvious change in the fertility of different soil types above 325m. while the fertility of soil type below 325m decreases obviously
1993, 6(5): 510-516.
Abstract:
This paper, taking Chinese fir (Cunninghamia lanceolata Hook) as an example, introduce an approach to derive Stand Density Control Chart (SDCC) from the Integrated Stand Growth Model (ISGM). The approach ensures that the SDCC and the common stand tables derived from ISGM such as the normal yield table, V-G table, growth table of unthinned stand in relation to spacing are compatible.
This paper, taking Chinese fir (Cunninghamia lanceolata Hook) as an example, introduce an approach to derive Stand Density Control Chart (SDCC) from the Integrated Stand Growth Model (ISGM). The approach ensures that the SDCC and the common stand tables derived from ISGM such as the normal yield table, V-G table, growth table of unthinned stand in relation to spacing are compatible.
1993, 6(5): 517-521.
Abstract:
Laboratory rearing and simulated field overwintering of Sphedanolestes impressicollis Stal were conducted in Beijing in 1991-1992. It has one generation a year and overwinters in 4 th instar in nymphal stage. The eggs aggregate in the form of egg masses, and hatch in 9.9+1.1 days after oviposition. There are 5 instars in nymphal stage and its development lasts for 315.0±4.9 days. The adults mate in 7~25 days after emergence and oviposit 22~23 days later. Not only its morphology and changes in color after moulting in all stages but also the bionomics were described. Experiments both in laboratory and in the field showed that it is a promising predator and can prey on Clostera anachoreta (Fabricius), Cnidocampa flavesccns (Walker), Nematus sp., Lymantria dispar (L.), Dendrblimus tabulaeformis Tsai et Liu, Malacosoma neustriatestacea Motschulsky,Aphis robi-niae Macchiati etc. many species of forest pests.
Laboratory rearing and simulated field overwintering of Sphedanolestes impressicollis Stal were conducted in Beijing in 1991-1992. It has one generation a year and overwinters in 4 th instar in nymphal stage. The eggs aggregate in the form of egg masses, and hatch in 9.9+1.1 days after oviposition. There are 5 instars in nymphal stage and its development lasts for 315.0±4.9 days. The adults mate in 7~25 days after emergence and oviposit 22~23 days later. Not only its morphology and changes in color after moulting in all stages but also the bionomics were described. Experiments both in laboratory and in the field showed that it is a promising predator and can prey on Clostera anachoreta (Fabricius), Cnidocampa flavesccns (Walker), Nematus sp., Lymantria dispar (L.), Dendrblimus tabulaeformis Tsai et Liu, Malacosoma neustriatestacea Motschulsky,Aphis robi-niae Macchiati etc. many species of forest pests.
1993, 6(5): 522-526.
Abstract:
To raise the effect of killing weeds on grassland, screening of chemical herbicides for fire-preventing lines was conducted in Inner Mongolia. Glyphosate + butlate and Glyphosate + Velpar were used as mixtures to carry out the experiments. The weed-eliminating rate of them could reach over 95%. Meanwhile, the mechanism of Glyphosate was also discussed.
To raise the effect of killing weeds on grassland, screening of chemical herbicides for fire-preventing lines was conducted in Inner Mongolia. Glyphosate + butlate and Glyphosate + Velpar were used as mixtures to carry out the experiments. The weed-eliminating rate of them could reach over 95%. Meanwhile, the mechanism of Glyphosate was also discussed.
1993, 6(5): 527-530.
Abstract:
Puffballs of Pisolithus tinctorius were used to prepare spore slurry with loess and tap water (1:2:100). The spore slurry was then inoculated onto the container-grown Caribbean pine seedlings which were growing at six different concentrations of phosphate fertilizer-calcium, superphosphate. The results showed that both in nursery and field, the pine seedlings inoculated with P. tinctorius performed much better than the uninocu-lated ones, especially in root collar and dry weight. Meanwhile, the application of phosphate fertilizer at the proper concentration could accelerate the growth of inoculated seedlings. Generally, the pine seedlings inoculated with P. tinctorius at the concentration of 0.5%~7.0% calcium superphosphate would grow the best.
Puffballs of Pisolithus tinctorius were used to prepare spore slurry with loess and tap water (1:2:100). The spore slurry was then inoculated onto the container-grown Caribbean pine seedlings which were growing at six different concentrations of phosphate fertilizer-calcium, superphosphate. The results showed that both in nursery and field, the pine seedlings inoculated with P. tinctorius performed much better than the uninocu-lated ones, especially in root collar and dry weight. Meanwhile, the application of phosphate fertilizer at the proper concentration could accelerate the growth of inoculated seedlings. Generally, the pine seedlings inoculated with P. tinctorius at the concentration of 0.5%~7.0% calcium superphosphate would grow the best.
1993, 6(5): 531-535.
Abstract:
In this paper, the effect of paclobutrazol on the growth and development of walnut and its physiological mechanism were studied. The results showed that paclobutrazol (1000~2000 ppm) could significantly depress the growth of shoot (decreased the length and thickness of shoots), reduce the trunk diameter and single leaf area, increase the number of nuts and greatly raised the yield per plant. The physiological effects of paclobutrazol on walnut were as follows; increase the concentrations of chlorophyll, soluble sugar and protein in leaves, reduce the contents of GA3, IAA and ABA in shoot tips or buds, and had no influence on the quality of nuts. The paper also discussed the possible mechanism of paclobutrazol affecting walnuts.
In this paper, the effect of paclobutrazol on the growth and development of walnut and its physiological mechanism were studied. The results showed that paclobutrazol (1000~2000 ppm) could significantly depress the growth of shoot (decreased the length and thickness of shoots), reduce the trunk diameter and single leaf area, increase the number of nuts and greatly raised the yield per plant. The physiological effects of paclobutrazol on walnut were as follows; increase the concentrations of chlorophyll, soluble sugar and protein in leaves, reduce the contents of GA3, IAA and ABA in shoot tips or buds, and had no influence on the quality of nuts. The paper also discussed the possible mechanism of paclobutrazol affecting walnuts.
1993, 6(5): 536-540.
Abstract:
This paper deals with the primary productivity of medium and high yield bamboo (Phyllostachys pubescens) groves.The results show that the increase of biomass above ground is mainly from newly growing bamboo. the more the new grown-up bamboos, the more the increase of primary productivity of bamboo. Furthermore, the increase of culm-wall density for 1~3 year bamboos has also the influence over the increase of biomass of bamboo groves. Besides, the biomass production of rhizomes and roots has a close connection with the site conditions. The under-ground biomass covers only a small proportion in the bamboo groves, which has a close relation with water and soil fertility. As the site condition becomes worse and management level low,the proportion of under ground biomass will increase.
This paper deals with the primary productivity of medium and high yield bamboo (Phyllostachys pubescens) groves.The results show that the increase of biomass above ground is mainly from newly growing bamboo. the more the new grown-up bamboos, the more the increase of primary productivity of bamboo. Furthermore, the increase of culm-wall density for 1~3 year bamboos has also the influence over the increase of biomass of bamboo groves. Besides, the biomass production of rhizomes and roots has a close connection with the site conditions. The under-ground biomass covers only a small proportion in the bamboo groves, which has a close relation with water and soil fertility. As the site condition becomes worse and management level low,the proportion of under ground biomass will increase.
1993, 6(5): 541-546.
Abstract:
The Banhgladesh Lac insect, Kerria sindica Mahd. is superior to Kerria chinensis Mahd. in China in terms of the resin secreted. Introduction of that insect aims at exploring the possibility of propagating it under domestic conditions followed by popularization on a large scale to provide shellac of fine quality.It has been researched for 3 years and 7 months from attempting inoculation to successful large-scale propagation through 7 generations.The expected goal has been achieved with more than 2000 kg of raw lac being produced in this period of time.It appears that this species of lac insect has a bright future to be bred in some suitable area in China.
The Banhgladesh Lac insect, Kerria sindica Mahd. is superior to Kerria chinensis Mahd. in China in terms of the resin secreted. Introduction of that insect aims at exploring the possibility of propagating it under domestic conditions followed by popularization on a large scale to provide shellac of fine quality.It has been researched for 3 years and 7 months from attempting inoculation to successful large-scale propagation through 7 generations.The expected goal has been achieved with more than 2000 kg of raw lac being produced in this period of time.It appears that this species of lac insect has a bright future to be bred in some suitable area in China.
1993, 6(5): 547-555.
Abstract:
According to the rattan distribution region, the division region is delimited. On the basis of the results of principal component analysis and clustering analysis on six climatic factors which are closely related to the growth and ecological characters of rattans, the climatic region of rattan cultivation have been divided. Then, in accordance with the achievement of comprehensive rattan research and experience of rattan cultivation, together with the cultivation requirements of main commercial rattan species, the whole region suitable for rattan planting in the south of china is divided into four divisions, and suitable commercial rattan species as well as their planting technique for each division are presented in this paper.
According to the rattan distribution region, the division region is delimited. On the basis of the results of principal component analysis and clustering analysis on six climatic factors which are closely related to the growth and ecological characters of rattans, the climatic region of rattan cultivation have been divided. Then, in accordance with the achievement of comprehensive rattan research and experience of rattan cultivation, together with the cultivation requirements of main commercial rattan species, the whole region suitable for rattan planting in the south of china is divided into four divisions, and suitable commercial rattan species as well as their planting technique for each division are presented in this paper.
1993, 6(5): 556-564.
Abstract:
After a study on the volume growth and wood properties of 10-year-old masson pines of 90 seed sources, significant variations were found in stem volume and wood basic density. Stem volume increased and wood density decreased gradually from north to south. The seed sources of the trees with greatest wood density was from northwest of the range and the smallest from the middle belt. There were very small effect of seed source and no definite geographic pattern in tracheid length. Considering the significant nagative genetic correlation between stem volume and basic density and the marked provenance effects for both traits, we would emphasize growth (volume) as the primary target trait and wood quality (basic density) as secondary one when selecting superior provenances or seed sources. Using the unrestricted selection index combining stem volume with basic density, we found that the zone including western Fujian,central and southern Jiangxi, southern end of Hunan, northwestern Guangdong and southeast of Guangxi was the optimum provenance region for paper-pulp wood of masson pine.
After a study on the volume growth and wood properties of 10-year-old masson pines of 90 seed sources, significant variations were found in stem volume and wood basic density. Stem volume increased and wood density decreased gradually from north to south. The seed sources of the trees with greatest wood density was from northwest of the range and the smallest from the middle belt. There were very small effect of seed source and no definite geographic pattern in tracheid length. Considering the significant nagative genetic correlation between stem volume and basic density and the marked provenance effects for both traits, we would emphasize growth (volume) as the primary target trait and wood quality (basic density) as secondary one when selecting superior provenances or seed sources. Using the unrestricted selection index combining stem volume with basic density, we found that the zone including western Fujian,central and southern Jiangxi, southern end of Hunan, northwestern Guangdong and southeast of Guangxi was the optimum provenance region for paper-pulp wood of masson pine.
1993, 6(5): 565-568.
Abstract:
Eleven common diseases of Rattan were reported. Among them, Phyllosticta leaf blight, Coniothyrium spot, Anthracnose, Seedling stem shrinkage, Melanconium spot, Sun scald, Monochaetia spot, Pyreno-chatta spot, Sooty mold and Algal spot are reported for the first time in China. Symptoms, pathogens, occurrence and control of the chief diseases are also described briefly in this report.
Eleven common diseases of Rattan were reported. Among them, Phyllosticta leaf blight, Coniothyrium spot, Anthracnose, Seedling stem shrinkage, Melanconium spot, Sun scald, Monochaetia spot, Pyreno-chatta spot, Sooty mold and Algal spot are reported for the first time in China. Symptoms, pathogens, occurrence and control of the chief diseases are also described briefly in this report.
1993, 6(5): 569-572.
Abstract:
Testing material of poplars;Populus deltoides Bartr. cl. ‘Zhong-lin 28', cl. ‘Zhonglin 46',cl. ‘Zhonglin 115' and P. canadensis ‘I-214', P. ×euramericana‘Cima', and P. ×euramericana ‘Avanzo' were collected from the poplar provenance conservation plantations in the Baoding Prefecture Forest Research Institute, Hebei Province. Their wood anatomy, chemicl composition, physical and mechanical properties were studied. The results showed the differences of the wood properties of the 6 poplar clones, which can be used as scientific foundations for selection of fine clones and wood utilization of new poplar clones.
Testing material of poplars;Populus deltoides Bartr. cl. ‘Zhong-lin 28', cl. ‘Zhonglin 46',cl. ‘Zhonglin 115' and P. canadensis ‘I-214', P. ×euramericana‘Cima', and P. ×euramericana ‘Avanzo' were collected from the poplar provenance conservation plantations in the Baoding Prefecture Forest Research Institute, Hebei Province. Their wood anatomy, chemicl composition, physical and mechanical properties were studied. The results showed the differences of the wood properties of the 6 poplar clones, which can be used as scientific foundations for selection of fine clones and wood utilization of new poplar clones.
1993, 6(5): 573-578.
Abstract:
Two progeny testing plantations which contained the same open-pollinated progenies of slash pine (Pinus elliottii) were established. These two plantations were of randomized and complete block design, 48 offspring per family and 4-tree plot. Height and diameter at breast height were measured in the 5-year-old progeny test stands, and these data were used to analyze the relationship between families (or parents) ranking or family heritability and family sizes or plot sizes. The results show that the required minimum family size is 30 for obtaining reliable rank per family and family h2 in one single site test. But in two site tests, the minimum family sizes are different for family ranking and family h2, they are 10 and 30 respectively. Different sites and family sizes have different optimum plot sizes, in general, two or three-tree plot is more efficient than single or four-tree plot for estimating family ranking and family h2.
Two progeny testing plantations which contained the same open-pollinated progenies of slash pine (Pinus elliottii) were established. These two plantations were of randomized and complete block design, 48 offspring per family and 4-tree plot. Height and diameter at breast height were measured in the 5-year-old progeny test stands, and these data were used to analyze the relationship between families (or parents) ranking or family heritability and family sizes or plot sizes. The results show that the required minimum family size is 30 for obtaining reliable rank per family and family h2 in one single site test. But in two site tests, the minimum family sizes are different for family ranking and family h2, they are 10 and 30 respectively. Different sites and family sizes have different optimum plot sizes, in general, two or three-tree plot is more efficient than single or four-tree plot for estimating family ranking and family h2.
1993, 6(5): 579-582.
Abstract:
In northern Fujian, the type of distribution of overwintering larvae and egg masses belongs to aggregation distribution, which is resulted from its biological characteristics and environmental heterogeneity. The relationship between site condition and pest density was studied, The results showed that its egg density was affected by the vegetation in the forest. And the density of egg and larvae decreases with the increase of crown density. The percentage of trees infested is positively related to the larvae and/or egg density. The formula is fitted for the expression of relation between pest density and percentage of trees infested. However, attention should be paid to the selection of appropriate high or low limits for the estimation of its population density.
In northern Fujian, the type of distribution of overwintering larvae and egg masses belongs to aggregation distribution, which is resulted from its biological characteristics and environmental heterogeneity. The relationship between site condition and pest density was studied, The results showed that its egg density was affected by the vegetation in the forest. And the density of egg and larvae decreases with the increase of crown density. The percentage of trees infested is positively related to the larvae and/or egg density. The formula is fitted for the expression of relation between pest density and percentage of trees infested. However, attention should be paid to the selection of appropriate high or low limits for the estimation of its population density.
1993, 6(5): 583-587.
Abstract:
This paper chose KI as the most appropriate contrast agent for masson pine seeds. The x-ray contrast method proceeded as follows;The seeds were soaked in tapwater at 25℃ for 12h, and superficially dried, then steeped in 40% solution of KI for 1.5h. After washing in running water for 2min, the seeds were dried at 70℃ for 2h. The dried seeds were radiographed under the following conditions;voltage=20 kV, electric current=3mA, exposure time=60sec, focus-film-distance=25cm. The unim-pregnated normal seed was considered as viable seed for calculating germi-nability. The germinability (x) of 41 seed samples was very close to the germination percent (y). The relationship was y=-4.7+1.07x, r=0.96.
This paper chose KI as the most appropriate contrast agent for masson pine seeds. The x-ray contrast method proceeded as follows;The seeds were soaked in tapwater at 25℃ for 12h, and superficially dried, then steeped in 40% solution of KI for 1.5h. After washing in running water for 2min, the seeds were dried at 70℃ for 2h. The dried seeds were radiographed under the following conditions;voltage=20 kV, electric current=3mA, exposure time=60sec, focus-film-distance=25cm. The unim-pregnated normal seed was considered as viable seed for calculating germi-nability. The germinability (x) of 41 seed samples was very close to the germination percent (y). The relationship was y=-4.7+1.07x, r=0.96.
1993, 6(5): 588-591.
Abstract:
This paper dealt with the research on the activities of pheny-lalanine ammonialyase (PAL) in the poplar clones of Aigeiros section, including I-63, I-69 and I-72. The maximal activities of PAL in the barks of their 1-year-old dormant stems were seen in the top of stem without exception, and those of them were similar in main. But in their middle and basal parts the PAL activities varied with clones significantly, among them that of I-69 poplar was the highest, and this difference continued all the way up to their sprouting. The photomicrographes of their sprouting stem sections showed that the vessel elements in the stem sprout of I-69 poplar were well-developed and are much better than those in I-72 poplar. This phenomenon was in accordance with the difference between their PAL activities, which indicated that the PAL activity was closely related to the lig-nif ication of the poplar stem. The sequence of PAL activities in the leaves of various clones during the developing process from their winter buds to the complete leaves mainly coincided with those in the barks of dormant stem and stem sprout of corresponding clones.
This paper dealt with the research on the activities of pheny-lalanine ammonialyase (PAL) in the poplar clones of Aigeiros section, including I-63, I-69 and I-72. The maximal activities of PAL in the barks of their 1-year-old dormant stems were seen in the top of stem without exception, and those of them were similar in main. But in their middle and basal parts the PAL activities varied with clones significantly, among them that of I-69 poplar was the highest, and this difference continued all the way up to their sprouting. The photomicrographes of their sprouting stem sections showed that the vessel elements in the stem sprout of I-69 poplar were well-developed and are much better than those in I-72 poplar. This phenomenon was in accordance with the difference between their PAL activities, which indicated that the PAL activity was closely related to the lig-nif ication of the poplar stem. The sequence of PAL activities in the leaves of various clones during the developing process from their winter buds to the complete leaves mainly coincided with those in the barks of dormant stem and stem sprout of corresponding clones.
1993, 6(5): 594-596.
Abstract:
China manfispoides (Walker) which infests Carya cathayensis Sarg is reported in this paper. It has one generation a year and overwinters as egg in soil. The overwintered eggs hatch in late May. There are five instars of nymph, the first instar nymph infests the plant near the ground, the second instar infests leaves of the tree in the middle of June. Adults make the most serious damage to the tree in the middle of October. 90% of the, nymphs can be killed by 25% pyrethorn (1:1500). More than 90% of adults can be attracted and killed by rice stalks saturated in the mixture of 90% trichlorfon and fresh urine.
China manfispoides (Walker) which infests Carya cathayensis Sarg is reported in this paper. It has one generation a year and overwinters as egg in soil. The overwintered eggs hatch in late May. There are five instars of nymph, the first instar nymph infests the plant near the ground, the second instar infests leaves of the tree in the middle of June. Adults make the most serious damage to the tree in the middle of October. 90% of the, nymphs can be killed by 25% pyrethorn (1:1500). More than 90% of adults can be attracted and killed by rice stalks saturated in the mixture of 90% trichlorfon and fresh urine.
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