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《Forestry Studies in China》

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Competition effects in an afrotemperate forest 被引量:2
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作者 Thomas Seifert Stefan Seifert +2 位作者 Armin Seydack Graham Durrheim Klaus von Gadow 《Forestry Studies in China》 CAS 2014年第3期119-133,共15页
Background: Information about competition responses is mainly available for monospecific stands or mixed stands with a small number of species. Studies on complex multi-species and highly structured forest ecosystems... Background: Information about competition responses is mainly available for monospecific stands or mixed stands with a small number of species. Studies on complex multi-species and highly structured forest ecosystems are scarce. Accordingly, the objective of this study was to quantify competition effects and analyse competition responses in a species-diverse afrotemperate forest in South Africa, based on an observational study with mapped tree positions and long-term diameter increment records. Methods: The sensitivity to competition was analysed for individual species and involved the calculation of the slope of the linear relation between the value of a competition index (CI) and diameter growth as a measure of sensitivity. In a next step different competition indices were combined and tree diameters were grouped in three classes as surrogates for canopy status and ontogenetic stage. Results: Five competition indices were found to be effective in showing sensitivity to competition for a number of canopy and sub-canopy species. Significant linear regressions were fitted for 18 of a total of 25 species. Species reactions varied significantly in their sensitivity to the different CIs. The indices were classified as belonging to two groups, those that responded more to local crowding and those that are more sensitive to overtopping, which revealed species-specific sensitivities to both factors. The analysis based on diameter classes revealed that species clearly changed their sensitivity to crowding or overtopping depending on diameter. Canopy and sub-canopy species showed distinct differences in their reactions. Conclusions: The application of multiple CIs brought novel insights relating to the dynamics of afrotemperate forests. The response patterns to different competition indices that focus on crowding and overtopping are varied and tree diameter dependent, indicating that oversimplified assumptions are not warranted in the interpretation of Cl- growth relations. 展开更多
关键词 Observational study Multi-species forest Distance dependent competition indices Simultaneous competitionindex approach Tree-tree interaction Ontogenetic effect
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Observations on bud burst phenology in a field trial established with Poplar (Populus spp.)
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作者 Md. Salim AZAD 《Forestry Studies in China》 CAS 2012年第4期251-259,共9页
Bud flushing is very important for the survival and growth of trees, a phenomenon matched each year with the annual course of temperature and the timing of bud flushing in the spring. Essentially it represents a serio... Bud flushing is very important for the survival and growth of trees, a phenomenon matched each year with the annual course of temperature and the timing of bud flushing in the spring. Essentially it represents a serious ecological and evolutionary tradeoff between survival and growth. The most suitable timing of bud burst permits trees to begin growth sufficiently early to take advantage of favorable spring conditions, but late enough to decrease the risks of tissue damage from late frost. In the present study bud burst spring phenology of poplar (Populus tremula and P. tremuloides) from eight different provenances, originating from Eu- rope and the USA, was observed during March and April, 2009. The experimental plot was located at Solling, Germany (51~44'0" N, 9036'0'' E). A six stage subjective scoring system of bud burst phenology was used to identify the phenological stages of the seed- lings, where each plant was observed twice a week. The aim of the study was to predict phenotypic variation in poplar, originating from regions between 42~ and 60~ N latitude, growing in similar environments. Timing of bud flushing of poplar was recorded. It was found that seedlings of provenance 3, which originated from 42.35~ N latitude, started and completed flushing significantly earlier than those of other provenances, while seedlings of provenance 5, originating from 54.29~ N latitude, started flushing very late and only a few plants reached top scoring at the end of the experimental period. Analysis of variance showed statistically highly signifi- cant differences (p 〈 0.05) in bud flushing among the provenances. The correlation between scoring and flushing periods was very strong within provenances although the flushing pattern differed among provenances (origin of the planted seedlings). Bud flushing showed a negative correlation with the origin of the planted seedlings. Given the field experience gained with this experiment, it is recommended that seedlings from provenances 5 and 8 could be used for future plantations where late frost may be a problem for the young shoots of seedlings. 展开更多
关键词 bud flushing DORMANCY genetic variation phenotype Populus tremula Populus tremuloides
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Temporal and spatial variation of pollen yield in natural populations of Pinus roxburghii
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作者 Vinod Prasad KHANDURI 《Forestry Studies in China》 CAS 2012年第1期20-29,共10页
Male components of the reproduction process in Pinus roxburghii were investigated for their variation in time and space as well as pollination, viz. flowering phenology, pollen production variability and pollen disper... Male components of the reproduction process in Pinus roxburghii were investigated for their variation in time and space as well as pollination, viz. flowering phenology, pollen production variability and pollen dispersal, for five successive years at two different locations (at the lower and higher elevations). The study reveals that elevation and the hour of the day are the main determi- nants of anthesis and microsporangium dehiscence, because both are related to temperature and humidity. The receptivity of ovulate cone strobili or female strobili occurred earlier at the lower elevation than at the higher elevation, with a longer receptivity period in the latter case. The phenology of male and female cones varied significantly between years and elevations. The determinations of pol- len yield considered various sources of variability, i.e., the number of pollen strobili per branch, strobili per tree, microsporangia per tree and pollen grains per tree. Each of these parameters revealed significant year-to-year and elevation effects. Year-to-year varia- tion in the production of pollen cone and pollen grains with mass production after a three-year period revealed a three-year cycle of masting in pollen production in P. roxburghii. The pollen dispersal decreased quickly with distance from the pollen source. As a con- sequence, a distance of 600 m was proposed as a minimum to prevent contamination by pollen in the management of seed orchards. The results ultimately suggest that the ample production of pollen grains per tree along with flowering synchrony and long dispersal of pollen grains results in homogeneity in large populations. 展开更多
关键词 chir pine pollen cone gene flow ELEVATION HIMALAYAS
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Resistance to Adversity of New Poplar Clones
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作者 Qin Guanghua Jiang Yuezhong Qiao Yuling Shandong Academy of Forestry, Jinan 250014, P.R.China 《Forestry Studies in China》 CAS 2003年第4期18-21,共4页
With four poplar clones, namely 84-323 (Populus deltoides cv. ?4-323?, 84-324 (Populus deltoides cv. ?4-324?, 79-35 (Populus ?euramericana cv. ?9-35?, and I-69 (Populus deltoides cv. 慙ux?I-69/55) as a control, resear... With four poplar clones, namely 84-323 (Populus deltoides cv. ?4-323?, 84-324 (Populus deltoides cv. ?4-324?, 79-35 (Populus ?euramericana cv. ?9-35?, and I-69 (Populus deltoides cv. 慙ux?I-69/55) as a control, researches on cold, drought and salt resistance of the clones were conducted. Electrolyte permeability under a series of low temperatures, relative water loss rate of detached leaves with time series and survival rate and growth performance in salt soil were measured. The results showed that 84-323, 84-324 and 79-35 were resistant to cold as same as I-69 (CK) and more resistant to drought and salinity than I-69 (CK). 展开更多
关键词 POPLAR CLONES cold endurance drought tolerance salt resistance
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Status and Advances of Researches on GA 20-oxidases 被引量:2
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作者 Li Wei Chen Xiaoyang Li Hui Guo HaiCollege of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P. R. China 《Forestry Studies in China》 CAS 2003年第1期49-54,共6页
GA 20-oxidase, the most important limiting enzyme, can catalyze a series of oxidization of GA biosynthesis pathway from GA12 to GA9 and from GA53 to GA20 in the higher plants. This paper reviews the studies on the cha... GA 20-oxidase, the most important limiting enzyme, can catalyze a series of oxidization of GA biosynthesis pathway from GA12 to GA9 and from GA53 to GA20 in the higher plants. This paper reviews the studies on the characters of GA 20-oxidase, the gene and the protein of GA 20-oxidase and the regulation of GA 20-oxidase gene expression in recent years. At the same time, the prospects for the gene transformation of GA 20-oxidase in agriculture, forestry and horticulture are also discussed. 展开更多
关键词 higher plants GA 20-oxidase gene transformation
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Test of Insect-Resistance of Transgenic Poplar with CpTI Gene 被引量:1
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作者 张谦 林善枝 +1 位作者 张志毅 林元震 《Forestry Studies in China》 CAS 2002年第2期27-32,共6页
Both non-transgenic hybrid triploid poplars [ (Populus tomentosa×P.bolleana)×P.tomentosa ] and transgenic ones expressing cowpea trypsin inhibitor were cut at the base of the stem to produce auxoblasts, an... Both non-transgenic hybrid triploid poplars [ (Populus tomentosa×P.bolleana)×P.tomentosa ] and transgenic ones expressing cowpea trypsin inhibitor were cut at the base of the stem to produce auxoblasts, and used as source of leaves for insect feeding trials performed on 3 major insect species of poplar, the forest tent caterpillar ( Malacosoma disstria L.), gypsy moth ( Lymantria dispar L.) and willow moth ( Stilpnotia candida Staudinger). The height and basal diameter of trees were measured by the end of that year (2000). The results indicated that the growth elements of transgenic poplars were not interfered by the incorporation of the CpTI gene. Intriguingly, the height and basal diameter of the clone TG04 were much greater than that of the control. The transgenic foliage consumed by insects induced the increase of larval mortality, and decrease of larval wet weight gain, faecal output, pupal weight and egg deposition. Among them 3 transgenic clones, TG04, TG07 and TG71 received special attention for their outstanding insect resistance compared with other transgenic clones, which showed that the CpTI gene in them was expressed more actively and stably than in others. 展开更多
关键词 cowpea trypsin inhibitor Populus tomentosa LEPIDOPTERA insect resistance
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A Natural Hybrid of Cymbidium From China 被引量:1
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作者 刘仲健 陈心启 《Forestry Studies in China》 CAS 2001年第1期23-25,共3页
An intermediate between Cymbidium lancifolium Hook. and C.ensifolium (L.) Sw. is described as a new hybrid of them: C.× oblancifolium I. J. Liu et S. C. Chen. It is widespread in southern Sic huan Province in so... An intermediate between Cymbidium lancifolium Hook. and C.ensifolium (L.) Sw. is described as a new hybrid of them: C.× oblancifolium I. J. Liu et S. C. Chen. It is widespread in southern Sic huan Province in southwestern China . After being introduced into cultivation, it remains steady in its character an d indicates remarkable growth. It also exhibits great aesthetic values. 展开更多
关键词 Cymbidium×oblancifolium new species natural hybrid CULTIVATION
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Effect of steam pretreatment on wood moisture content and characteristics of vacuum drying 被引量:2
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作者 PENG Yi-qing LI Fan +1 位作者 YANG Fei YI Song-lin 《Forestry Studies in China》 CAS 2012年第4期315-319,共5页
The effects of high temperature steam pretreatment on the change in wood moisture content (MC) and characteristics of vacuum drying were investigated in this study. Poplar and manchurian walnut woods were pretreated... The effects of high temperature steam pretreatment on the change in wood moisture content (MC) and characteristics of vacuum drying were investigated in this study. Poplar and manchurian walnut woods were pretreated with high temperature steam at 100~C and 140~C, prior to vacuum drying. A comparison of the characteristics of vacuum drying between steam pretreated wood and untreated wood was carried out. The results show that during steam pretreatment, the MC of wood decreased within a few hours. The reduction of MC varied with the temperature; the higher the temperature, the faster the MC dropped. During the vacuum drying stage, the rates of drying ofpretreated samples were higher than those of untreated samples when MC was below the fiber saturation point. Furthermore, the total drying time of samples treated at a steam temperature of 140~C was lower than that of untreated samples. Therefore, a vacuum procedure after steam pretreatment can effectively shorten the drying time when drying wood. 展开更多
关键词 steam pretreatment moisture content vacuum drying fiber saturation point
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Selected physical and chemical properties of mechanically extracted neem seed oil sourced as a preservative for ligno-cellulose in south-western Nigeria
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作者 Andrew A. ERAKHRUMEN 《Forestry Studies in China》 CAS 2011年第4期263-269,共7页
Most of the seeds produced by neem (Azadirachta indica A. Juss) trees in Nigeria are currently underutilized. Hence, relevant literature provides only limited information conceming many of the seed oils from this co... Most of the seeds produced by neem (Azadirachta indica A. Juss) trees in Nigeria are currently underutilized. Hence, relevant literature provides only limited information conceming many of the seed oils from this country, especially where it concems the potential applications of these oils as preservatives for ligno-cellulose against bio-deterioration. Using standard procedures therefore, this study was carried out to evaluate and document selected physical and chemical properties of neem seed oil (NSO), mechanically extracted using a cold press at 31.03 N-mm^-2 pressure and a room temperature of 25 ± 2℃. The results show that oil yield was 38.42% with a specific gravity of 0.91 ± 0.01. The amount of acid was 18.24 ± 1.31 mg KOH.g^-1 and that of iodine 93.12 ± 2.01 g-100 g^- 1, while saponification and peroxide values were 172.88 ± 2.06 and 1.42 ± 0.04 mg·g^-1 respectively. The implication of the values obtained, particularly those for the chemical properties, as they concern the potential application of NSO as a preservative for ligno-eellulose, is likely that it may be useful in this regard since the values may support some of the documented anti-microbial properties of the oil, although other physical and chemical properties that may affect this potential are recommended for investigations. Conclusions and other recommendations follow in line with the results of the study. 展开更多
关键词 neem seed oil physical and chemical properties mechanical extraction cold press
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Chemical control of Apriona germari(Hope) larvae with zinc phosphide sticks
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作者 SHUI Sheng-ying WEN Jun-bao +3 位作者 CHEN Min HU Xiao-li LIU Fang LI Jing 《Forestry Studies in China》 CAS 2009年第1期9-13,共5页
Larvae of Apriona germari (Hope), found widely in China, cause serious damage to trees and are difficult to control. Since some biological control methods have not been applied effectively in the field, chemical con... Larvae of Apriona germari (Hope), found widely in China, cause serious damage to trees and are difficult to control. Since some biological control methods have not been applied effectively in the field, chemical control methods are used widely. Because of low cost, no poisonous residues and relatively safe application, zinc phosphide sticks have been tested to control the larvae as a matter of urgency. However, there were no criteria about the dosage and use. Given the characteristics of larvae tunnels on triploid Populus tomentosa trees and the one-on-one way of using poison-fumigated sticks, the larvae were treated by three treatments with zinc phosphide sticks. The treatments are as follows: inserting one stick into the first hole of the tunnel from bottom to top (T1), inserting a stick into each of the lowest two holes (T2) and inserting one stick into the first and third hole from bottom to top separately (T3). We cleared the frass around the holes and on the ground before inserting the sticks and blocking every hole with mud for each treatment. After the fourth investigation was carried out, the larvae of CK were still active, and had caused serious damage and emanated fresh fi'ass from old and new holes. Some larvae treated with T1 and T2 were in an intermediate state, but all of the larvae treated with T3 died completely and their old holes had healed. The results show that inserting zinc phosphide sticks (the extent of dispersion of the sticks was 20%) is a feasible method to control A. germari (Hope) larvae in triploid P. tomentosa of pulpwood trees. Because there were no statistically significant differences (p 〉 0.05) among the three treatments, we recommend that T1 should be used for economic efficacy. 展开更多
关键词 Apriona germari LARVAE zinc phosphide sticks chemical control
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Cloning of plasma membrane H^+-ATPase gene in Populus euphratica Oliv. 被引量:1
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作者 Ning De-juan Hou Pei-chen +2 位作者 Hu Zan-min Shen Xin Chen Shao-liang 《Forestry Studies in China》 CAS 2006年第4期15-19,共5页
For this paper, the plasma membrane (PM) H^+-ATPase gene has been cloned from Populus euphratica Oliv. through a ho- mology based strategy. The isolated 3,210 bp cDNA contains a single 2,862 bp open reading frame ... For this paper, the plasma membrane (PM) H^+-ATPase gene has been cloned from Populus euphratica Oliv. through a ho- mology based strategy. The isolated 3,210 bp cDNA contains a single 2,862 bp open reading frame (ORF) which encodes a putative H^+-ATPase protein of 953 amino acid residues, with a significant homology to plasma membrane H^+-ATPase of Prunus persica, Phaseolus vulgaris, Sesbania rostrata and Daucus carota. The predicted protein has a molecular weight of 104,553 Da. The copy number analysis revealed multiple copies of the PM H^+-ATPase in the P. euphratica genome after digestion of their genomic DNA by the restriction enzymes EcoRI, NdeI, FbaI and Bg/Ⅱ, and Southern blot. 展开更多
关键词 H^+-ATPase Populus euphratica Oliv. gene cloning
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Constitutive Expression of Sense & Antisense PtAP3, an AP3 Homologue Gene of Populus tomentosa, Affects Growth and Flowering Time in Transgenic To-bacco 被引量:1
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作者 Wang Dong-mei An Xin-min Zhang Zhi-yi 《Forestry Studies in China》 CAS 2005年第3期22-27,共6页
To analyze the function of PtAP3, an APETALA3 (AP3) homologue gene isolated from Populus tomentosa Carr., the full length sequence (1797 bp) and a fragment (870 bp) of PtAP3 were fused to a CaMV 35S promoter of ... To analyze the function of PtAP3, an APETALA3 (AP3) homologue gene isolated from Populus tomentosa Carr., the full length sequence (1797 bp) and a fragment (870 bp) of PtAP3 were fused to a CaMV 35S promoter of pBI121 to generate the sense and antisense constructs of PtAP3. These constructs were transformed into tobacco by Agrobacterium infection of leaf disks and selection on kanamycin medium. Some sense and antisense transgenic tobacco plants were obtained by PCR and Southern blot analysis. Great phenotypic differences in transgenic tobacco plants were observed. Almost all of sense PtAP3 to transgenic tobaccos showed a higher growth rate than those of antisense transformants and a few developed pregnancy earlier than wild type seedlings and antisense transformants under the same conditions. 展开更多
关键词 expression PtAP3 Populus tomentosa construction transformation
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Genetic Control of Air-Dried Wood Density, Mechanical Properties and Its Implication for Veneer Timber Breeding of New Triploid Clones in Populus tomentosa Carr
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作者 邢新婷 张志毅 《Forestry Studies in China》 CAS 2002年第2期52-60,共9页
The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood... The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood density and some mechanical properties. The results showed that significant or extremely significant difference in air dried wood density and the mechanical properties existed among the clones, this means these wood properties were under moderate or strong genetic controls and could be improved by genetic manipulations. The radial and vertical variation patterns of air dried wood density were also studied and the results were found to coordinate with other previous research results. The vertical variation patterns of most mechanical properties within the individual tree also conformed to the general wood theories except the modulus of elasticity and cross section hardness. Among the mechanical properties, modulus of elasticity (MOE) and tangent section hardness were under strong genetic control, with the clonal repeatabilities being 0 90 and 0 80, respectively. However, the clonal repeatabilities of other mechanical properties under study were a little lower than above two indexes. Genetic correlation analysis indicated that super clonal selection and breeding for veneer timber could be realized through indirect selection of wood density and form indexes. 展开更多
关键词 Populus tomentosa Carr. triploid clones air dried wood density mechanical properties genetic variation
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Role of CaCl_(2) in Cold Acclimation-Induced Freezing Resistance of Populus tomentosa Cuttings 被引量:2
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作者 林善枝 林元震 +2 位作者 张志毅 雍军 张谦 《Forestry Studies in China》 CAS 2002年第2期38-42,共5页
Populus tomentosa cuttings were treated with 1mmol·L -1 , 5mmol·L -1 , 10mmol·L -1 or 15mmol·L -1 of CaCl 2 for 1\|7 d, respectively, for studying the effects of different conc... Populus tomentosa cuttings were treated with 1mmol·L -1 , 5mmol·L -1 , 10mmol·L -1 or 15mmol·L -1 of CaCl 2 for 1\|7 d, respectively, for studying the effects of different concentrations of CaCl 2 on freezing resistance. Results indicated that 10?mmol·L -1 of CaCl 2 has greater effect than other concentrations on the enhancement of freezing resistance, and the optimum time of pretreatment was 5?d. In addition, cuttings used for cold acclimation at -3℃ were pretreated with or without 10?mmol·L -1 of CaCl 2, 3?mmol·L -1 of Ca 2+ chelator EGTA, 0 05?mmol·L -1 of CaM antagonist CPZ or 0 1?mmol·L -1 of Ca 2+ channel inhibitor LaCl 3 The changes in CaM and freezing resistance of all cuttings were investigated. The results showed that cold acclimation at -3℃ increased CaM content and decreased the minimum temperature for 100% survival. The CaCl 2 pretreatment enhanced the effect of cold acclimation and obviously increased CaM content and decreased the minimum temperature for 100% survival, but this effect was strongly inhibited by the EGTA, CPZ or LaCl 3 It is concluded that the effect of CaCl 2 on freezing resistance is associated with its concentration and time of pretreatment, Ca 2+ CaM may be involved in the induction of freezing resistance of the cuttings. 展开更多
关键词 Populus tomentosa cuttings cold acclimation CaCl 2 CAM freezing resistance
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Relationship between rooting ability and endogenous phytohormone changes in successive continuous generation cuttings of Buxus sinica var. parvifolia, an endangered woody species in China 被引量:7
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作者 Huang Yan Ji Kong-shu Zhai Jin-ru 《Forestry Studies in China》 CAS 2007年第3期189-197,共9页
The objectives of this study were to investigate the effects of successive continuous generation (SCG) cuttings of Buxus sinica var. parvifolia on the rejuvenation of ortets at the hormone level, detect levels of in... The objectives of this study were to investigate the effects of successive continuous generation (SCG) cuttings of Buxus sinica var. parvifolia on the rejuvenation of ortets at the hormone level, detect levels of indoleacetic acid (IAA), abscisic acid (ABA), isopentenyladenosine (iPA), zeatin riboside (ZR) and gibberellin4 (GA4) during the rooting process of different generations by means of enzyme-linked immunosorbent assay (ELISA) technology and statistically analyze the rooting characteristics of cuttings. The results show that, the root systems of subsequent generations (generation 1998, 2000) developed satisfactorily, only a few initial generation (generation 1990, 1994) cuttings rooted and the root growth was inhibited. Around the period of callus formation and root projection through the epidermis, there was a marked, regular variation in the levels of IAA, ABA and GA4 between the initial generations and subsequent generations. 展开更多
关键词 Buxus sinica var. parvifolia PHYTOHORMONES successive continuous generation cutting REJUVENATION
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Suggestion to Contributors
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《Forestry Studies in China》 CAS 2004年第2期F005-F005,共1页
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Composition and Characteristics of Natural Secondary Forests in Shenzhen,South China
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作者 WangDianpei JiShuyi +1 位作者 ChenFeipeng PengShaolin 《Forestry Studies in China》 CAS 2004年第2期6-11,共6页
The composition and structure of five natural secondary forests in Shenzhen were studied based on data of plots and were compared with Hong Kong zonal forest, so as to detect their succession stage and species diversi... The composition and structure of five natural secondary forests in Shenzhen were studied based on data of plots and were compared with Hong Kong zonal forest, so as to detect their succession stage and species diversity level. According to succession process of subtropical forest and ecological characteristics of dominant species, the authors speculate that five communities are at different stages. Sinosideroxylon community dominated by heliophilous evergreen broad-leaved tree (Sinosideroxylon wightianum) and conifer tree (Pinus massoniana) is at the third stage. Itea + Acronychia community dominated by two evergreen broad-leaved heliophytes (Itea chinensis and Acronychia pedunculata) is at the fourth stage. The others, i.e., Schefflera, Sterculia and Cleistocalyx + Sterculia community are at the fifth stage where some mesophytes are dominant but heliophytes have a weighed percentage of importance value. Due to succession stage and different forest management and conservation models, the species diversity of five communities is significantly lower than that of Endospermum community in Hong Kong. The values of Shannon-Wiener index and Pielous evenness index of five communities are 2.04–2.953 and 64.2%–74% respectively, but those of the Endospermum community are 4.74 and 79% respectively. The current situation of these communities suggests that the necessary measures should be taken to protect and restore the communities. 展开更多
关键词 species composition community structure forest succession natural secondary forest heliophyte mesophyte
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Developmental Threshold Temperature and Effective Accumulative Tem- perature of Pupae and Eggs of Holcocerus hippophaecolus 被引量:8
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作者 ZongShixiang LuoYouqing WangTao XuZhichun LuChangkuan 《Forestry Studies in China》 CAS 2004年第4期34-38,共5页
In order to understand the occurrence and the developmental regularity of seabuckthorn carpenterworm (Holcocerus hippophaecolus) and predict its population density, the developmental threshold temperature (C) and effe... In order to understand the occurrence and the developmental regularity of seabuckthorn carpenterworm (Holcocerus hippophaecolus) and predict its population density, the developmental threshold temperature (C) and effective accumulative tem- perature (K) of the carpenterworm pupae and eggs were analyzed under the conditions of constant and variable temperatures. The results show that the values of C and K of the carpenterworm pupae are (12.1 ± 0.2) °C and (295.2 ± 4.1) day-degrees at constant temperatures, and (15.5 ± 0.4) °C and (202.4 ± 13.1) day-degrees at variable temperatures. However, the values of C and K of the eggs at variable temperatures are (16.7 ± 0.8) °C and (101.5 ± 12.6) day-degrees. The differences of developmental threshold and effective accumulative temperature under the conditions of constant and variable temperatures of the carpenterworm pupae accord with the developmental regularity of most insects in nature. By comparing five different constant temperatures, the conclusion is that the optimum developmental temperature of the pupae is 21 °C when both the pupation of the mature larvae and the eclosion of the pupae are very accordant. Moreover, the percentage of eclosion is over 90%. The average developmental durations of the carpenter- worm pupae and eggs are 31 and 16 d at variable temperatures. 展开更多
关键词 Holcocerus hippophaecolus PUPAE EGGS developmental threshold temperature effective accumulative tempera- ture
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Genetic Relationships among Prunus mume var. pendula Using AFLP Markers 被引量:3
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作者 Ming Jun Zhang Qixiang +3 位作者 Ru Guangxin Mao Qingshan Yan Xiaolan Lan Yanping 《Forestry Studies in China》 CAS 2003年第4期26-30,共5页
Genetic relationships among Prunus mume var. pendula were studied by using AFLP markers. 18 accessions representing 14 cultivars of Prunus mume var. pendula were selected from the germplasm collection at the Research ... Genetic relationships among Prunus mume var. pendula were studied by using AFLP markers. 18 accessions representing 14 cultivars of Prunus mume var. pendula were selected from the germplasm collection at the Research Center of China Mei Flower. Seven Mse I-EcoR I AFLP primer combinations revealed 450 legible bands, and 269 of which were polymorphic markers. A similarity matrix was prepared using the simple matching coefficient of similarity and Neis (72) distance coefficient. A UPGMA dendrogram demonstrated the genetic relationships of the cultivars. The information given by AFLP markers was basically consistent with the morphological classification and the evolutionary history of the morphotypes, and roughly supported the new revised classification system for Chinese Mei Cultivars. But there were still several exceptions: 1) the Guhong Chuizhi inserted between the Tiaoxue Chuizhi and the Danfen Chuizhi; 2) the Wufu Chuizhi kept off the Pink Pendant Form, and the Moshan Chuizhi was removed from Viridiflora Pendant Form; 3) the Danbi Chuizhi and the Shuangbi Chuizhi of Viridiflora Pendant Form got together well but fell within the Pink Pendant Form. 展开更多
关键词 Prunus mume Sieb. et Zucc. amplified fragment length polymorphism (AFLP) Prunus mume var. pendula (Pendulous Mei Group) genetic relationship
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Fixation and Creep of Compressed Wood of Chinese Fir Irradiated with Gamma Rays 被引量:1
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作者 王洁瑛 赵广杰 《Forestry Studies in China》 CAS 2001年第1期58-65,共8页
In order to discuss the mechanisms of permanent fixation of wood compression set , compressed wood of Chinese fir (Cunninghamia lanceolata) was irradiated by gamma rays from 60 Co. The irradiation doses wer... In order to discuss the mechanisms of permanent fixation of wood compression set , compressed wood of Chinese fir (Cunninghamia lanceolata) was irradiated by gamma rays from 60 Co. The irradiation doses were 0 (for match specim ens), 10 3, 5×10 3, 10 4, 5×10 4, 10 5, 5×10 5, 10 6, 5×10 6 Gy, res pectively. Then the weight loss, the equilibrium moisture content (EMC), the rec overy of wood compression set after adsorption (RSA) and the recovery after imme rsion in water (RSW), as well as the creep behaviour under a dry specimen condit ion and under an adsorption and subsequent desorption condition were measured an d discussed. This research proves that the doses of gamma irradiation have great effect on weight loss, EMC, RSA, RSW of irradiated compressed wood of Chinese f ir. The weight loss and the EMC increase, the RSA and the RSW fall drastically w hen the irradiation doses exceed 10 6 Gy. Both the instantaneous compliance and the creep compliance of the irradiated specimens under the two measurement cond itions show the general trend of increase with the increase of gamma irradiation doses. It can be deduced that decomposition or decrystallization reactions happ en in the wood cell wall at high gamma irradiation doses, especially at doses of around 5×10 6 Gy. In addition, this research proves that decomposition of mai n components of cell wall of compressed wood will lead to fixation of compressio n set of wood to a certain degree. 展开更多
关键词 gamma irradiation compressed wood Chinese fir fixa tion CREEP
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