修枝对尾巨桉林分生长及无节材形成的影响

开展尾巨桉不同修枝时间和修剪强度试验,分析修枝对桉树生长及材性的影响,结果表明:不同修枝时间和强度对林分生长和木材材质影响较大,从不同修枝时间看,适宜的修枝方案为D处理即造林当年7、8、10月份和第二年5、8月份各修枝1次,强度为1/5.该修枝方案与对照相比,林分平均树高、胸径、材积和高径比分别提高了24.3％、11.3％、56.8％和11.7％.从第二年8月6日不同修剪强度对林分生长来看,每次修枝1/5的B处理效果最好,修枝1/5的B处理与修枝3/5的E处理相比林分平均树高、胸径、材积和高径比分别提高了10.2％、6.4％、19.7和％3.4％.综合考虑不同修枝强度和不同修枝处理对尾巨桉林分生长和可获得无节材长度的影响,认为先后进行多次1/5修剪强度的D处理修剪方法最好.     

修枝对杉木幼林土壤肥力的影响初报

在福建洋口林场4年生的杉木人工林建立无节材培育试验地。选择修枝木,每年对其进行1次修枝,修枝强度为4种规定树干直径(6 cm、8 cm1、0 cm和12 cm)以下的所有枝条。试验3 a后研究不同修枝强度对7年生杉木林土壤肥力的影响,结果表明,试验后3 a,所有修枝试验林地的土壤0~10 cm和10~20 cm层次有机质、全N、水解性N和pH值的平均值均高于不修枝的对照,但差异未达到统计显著水平(P>0.05)。不同修枝强度及对照林地大多数土壤性质之间的差异未达到显著水平(P>0.05)。修枝后土壤性质有所改善,这可能与修枝后林下植被得到恢复有一定关系。修枝对杉木林地土壤性质的长期影响有待于今后进一步观测。     

不同修枝强度对杉木干形的影响

在福建省洋口国有林场进行不同强度的杉木幼林(4a生)修枝试验,修枝每年进行1次.试验后6 a(10 a生)调查了不同修枝强度(6、8、10、12 cm)及其对照(未修枝)的杉木不同高度处的直径并建立了高精度的削度方程,通过削度方程推算单株材积和形数.结果表明:修枝对杉木的胸高形数和H/D值有显著影响,胸高形数和H/D值均随着修枝强度的增加而增加,但修枝强度为12 cm的形数和H/D值却小于对照.     

几种优良桉树引种试验初报

对澳大利亚的大花序桉、托里桉、柳桉、巨桉进行引种及早期测试。结果表明,二年生大花序桉平均高232.5cm,平均胸径1.975cm;巨桉平均高660cm,平均胸径5.65cm;柳桉平均高670cm,平均胸径6.45cm;托里桉平均高507.5cm,平均胸径4.95cm.。从树高、胸径差数及T值差异性看,柳桉、巨桉生长量明显优于对照,托里桉与对照生长量则无明显差异,大花序桉明显低于对照生长量。     

杉木人工林无节材培育技术研究

采用目标树培育技术,通过人工修枝的方法来培育杉木人工林无节木材,以提高南方杉木木材的市场价值。为了形成一套较为完整的杉木无节材培育技术,按照不同的保留密度和修枝强度等因素进行试验设计。根据1999—2003年连续4 a的观测数据,分析结果表明,杉木8年生前林分的保留密度对杉木生长无显著影响,在1 800株.hm-2范围内可以采用较大的保留密度;不同的修枝强度对杉木生长造成显著影响,随着修枝强度的增大,杉木的树高、胸径和冠幅生长都显著下降,考虑到修枝效果和杉木生长两方面因素,以10 cm的修枝强度(修枝的基础粗度)最好。     

楸树幼林修枝试验报告

楸树幼林修枝强度准确实用的表示法为枝重比。以0％(对照)、25％、50％、75％、100％五种修枝强度对2年生楸树郁闭幼林进行修枝试验,结果以修枝25％效果最好,50％次之,使生长下降。与不修枝相比,修枝25％使当年胸径生长量提高13％;树高提高l5％;冠长增加4％;侧枝重量(鲜重)增加7％。建议楸树幼林采用25—40％的修枝强度,郁闭度达0.8或林龄4—5年开始第一次修枝。     

修枝对华北落叶松人工林分生长的初期影响

以河北省围场县木兰林管局管辖区的新丰林场试验林为基础,分析了修枝强度以及修枝剩余物的不同处理对华北落叶松人工林生长及冠层变化的影响。修枝强度设置3种,强(冠高比4/5)、中(冠高比7/10)、弱(冠高比3/5);对修枝剩余物处理分别为放置、清理、粉碎,并设置对照。结果表明:不同程度的修枝对林木的胸径生长率均有一定的提高作用,其中,中度修枝对林木胸径、树高生长率的促进和Vissky系数的提高较为明显;针对修枝剩余物不同处理试验的初期结果显示,粉碎处理和清理处理的林分,有利于林木胸径生长率的提高,放置处理的林分更有利于提高林木树高生长率。     

修枝起始年龄和季节对Ⅰ-69杨修枝口愈合的影响

对2007年春营造的Ⅰ-69杨进行了不同修枝处理,探讨了修枝起始年龄、修枝季节对修枝口愈合的影响。结果表明:Ⅰ-69杨修枝口(宽度W)越小,其完全愈合所需时间越短,完全愈合率也越高,宽度W<4 cm修枝口的完全愈合率明显大于W≥4 cm修枝口。修枝口愈合受到修枝枝龄的影响,随着枝龄的增长,较大修枝口所占比重增大,死枝修枝口数量也增多,修枝口的完全愈合率和愈合生长率均下降。修枝口愈合也受到修枝季节的影响,与冬季、夏季修枝相比,春季修枝的完全愈合率、愈合生长率明显较高。综合考虑修枝对杨树胸径生长量的影响,笔者认为Ⅰ-69杨的修枝起始年龄以第1轮枝条的年龄达到4年时为宜,修枝季节以春季(3月下旬至4月上旬)为宜。     

修枝对福建柏林分生长及无节材形成的影响

1998—2002年在福建省南靖国有林场对6年生福建柏林分进行的修枝试验表明:修枝促进林分生长和干物质的积累,修枝4a后,树高生长增加10 5%～20 9%,胸径生长增加2 6%～8 1%,单株生物量增加14 9%～37 2%,单株材积增加18 2%～44 3%,材积生长率提高3 48%～7 32%,林分蓄积量增加6 84～16 68m3·hm-2,其中促进林分生长效果最好的处理是修枝强度为50%;修枝降低了福建柏林木的尖削度,与对照相比较H/D值增加了7 0%～14 1%;在一定修枝强度范围内,修枝促进福建柏圆满度的增加;6年生开始修枝对降低尖削度、提高材积增长速率、促进节疤愈合效果最好,其次是5年生,11年生为最差;6年生的福建柏林分,在修枝强度为50%的条件下,树高、胸径、单株生物量、单株材积、材积生长率等以1200株·hm-2保留密度为最好。修枝强度和修枝间隔期可通过侧枝相对生长量法确定。     

欧美107杨速生丰产林不同修枝强度的研究

对欧美107杨进行不同强度修枝试验,通过近7a的观察研究,结果表明,不同强度修枝对欧美107杨的胸径、树高、材积、形率和形数、枝下高均有一定程度的影响,通过采取第3年、第5年进行中度修枝能够增加树木材积、增加树干圆满度、提高出材率,获得最大经济收益。     

Effect of pruning intensities of three woody leguminous species grown in alley cropping with maize and cowpea on an alfisol

Field trials were carried out on an Oxic Paleustalf in the humid zone of southwestern Nigeria withLeucaena leucocephala (Lam.) de Wit,Gliricidia sepium (Jacq.) Steud. andSesbania grandiflora (L.) Pers. alley cropped with maize and cowpea. The three leguminous woody species were grown in hedgerows spaced at 2 m. Trials were carried out one year after establishment of the hedgerows using a split-plot design with four replications. TheLeucaena trial had twenty pruning combinations consisting of five pruning heights (25, 50, 75, 100 and 150 cm) and four pruning frequencies (monthly, bi-, tri- and six-monthly). TheGliricidia andSesbania hedgerows were subjected to nine pruning intensities consisting of three pruning heights (25, 50 and 100 cm) and three pruning intensities (monthly, tri- and six-monthly).For the three woody species, biomass, dry wood and nitrogen yield from the hedgerow prunings increased with decreasing pruning frequency and increasing pruning height. Biomass, dry wood and nitrogen yields were in the following orderLeucaena >Gliricidia >Sesbania.The various pruning intensities had no effect on survival ofLeucaena plants. Pruning frequency had a larger effect than pruning height on survival ofGliricidia andSesbania plants. With monthly pruning, about 25 percent of theGliricidia and all of theSesbania plants died within six months of repeated pruning. Even with lower pruning frequencySesbania plants showed lower survival rates thanGliricidia orLeucaena.The various pruning intensities of all the hedgerow species had more pronounced effects on the grain yield of the alley cropped cowpea than on maize grain yield. Higher maize and cowpea yields were obtained with increasing pruning frequency and decreasing pruning height.IITA Journal paper number 335     

Effect of pruning intensities of three woody leguminous species grown in alley cropping with maize and cowpea on an alfisol

Field trials were carried out on an Oxic Paleustalf in the humid zone of southwestern Nigeria withLeucaena leucocephala (Lam.) de Wit,Gliricidia sepium (Jacq.) Steud. andSesbania grandiflora (L.) Pers. alley cropped with maize and cowpea. The three leguminous woody species were grown in hedgerows spaced at 2 m. Trials were carried out one year after establishment of the hedgerows using a split-plot design with four replications. TheLeucaena trial had twenty pruning combinations consisting of five pruning heights (25, 50, 75, 100 and 150 cm) and four pruning frequencies (monthly, bi-, tri- and six-monthly). TheGliricidia andSesbania hedgerows were subjected to nine pruning intensities consisting of three pruning heights (25, 50 and 100 cm) and three pruning intensities (monthly, tri- and six-monthly). For the three woody species, biomass, dry wood and nitrogen yield from the hedgerow prunings increased with decreasing pruning frequency and increasing pruning height. Biomass, dry wood and nitrogen yields were in the following orderLeucaena >Gliricidia >Sesbania. The various pruning intensities had no effect on survival ofLeucaena plants. Pruning frequency had a larger effect than pruning height on survival ofGliricidia andSesbania plants. With monthly pruning, about 25 percent of theGliricidia and all of theSesbania plants died within six months of repeated pruning. Even with lower pruning frequencySesbania plants showed lower survival rates thanGliricidia orLeucaena. The various pruning intensities of all the hedgerow species had more pronounced effects on the grain yield of the alley cropped cowpea than on maize grain yield. Higher maize and cowpea yields were obtained with increasing pruning frequency and decreasing pruning height. IITA Journal paper number 335     

Effects of pruning on radial growth and biomass increment of trees growing in homegardens of Kerala, India

To evaluate the effects of pruning on stem radial growth increment and leaf and twig biomass production, an experiment with four pruning intensities (0, 50, 75 and 90%) on ten locally important tree species (Ailanthus triphysa, Albizia odoratissima, Artocarpus hirsutus, Bombax malabarica, Bridelia crenulata, Erythrina indica, Grewia tiliifolia, Macaranga peltata, Terminalia paniculata and Xylia xylocarpa ), was carried out. The results did not support the contention that a certain level of pruning promotes stem growth in trees. Instead, all species have a level of pruning that reduces annual increment in stem diameter. In Ailanthus triphysa and Artocarpus hirsutus trees subjected to different pruning intensities showed a decline in the annual increment in stem diameter while in other species diameter increment reduced when the pruning intensity was 75% and 90%. Response to pruning in terms of biomass production also varied from species to species. In Erythrina indica, Macaranga peltata and Terminalia paniculata annual foliage and branch production in pruned trees was significantly more than that of the un-pruned trees. However, in Ailanthus triphysa, Albizia odoratissima, Artocarpus hirsutus, Bridelia crenulata, Grewia tiliifolia and Xylia xylocarpa pruned trees produced comparatively more amount of foliage and branches produced annually than that by the un-pruned trees when the pruning was carried out once in 2 years. Based on these observations it is recommended that trees of Erythrina indica, Macaranga peltata and Terminalia paniculata may be pruned at 50% level annually while the trees of Ailanthus triphysa, Albizia odoratissima, Artocarpus hirsutus, Bridelia crenulata, Grewia tiliifolia and Xylia xylocarpa may be pruned at the same pruning intensity once in 2 years.     

不同修剪强度对无患子生长和结果的影响

通过对无患子春梢进行不同强度的修剪处理,结果表明:轻度修剪最有利于新梢的萌发,进行轻剪处理的标准枝,平均新梢数为5.67条,极显著高于中剪和重剪处理的标准枝,是不修剪处理组的2.73倍。进行中度修剪的标准枝上萌发的新梢,其基径和梢长的生长情况均明显高出不修剪或经过轻剪和重剪处理的标准枝;经轻剪处理的标准枝,其平均开花枝数和平均坐果枝数分别为3.75条和2.58条,较未做修剪处理的标准枝1.33条的开花枝数和0.83条的坐果枝数,分别高出了181.95%和210.84%;较中剪处理组高出了80.29%和63.29%,较重剪处理组则高出了220.51%和180.43%;各处理组标准枝的新梢开花枝率和结果枝率则是随着修剪强度的增强而呈递增趋势;修剪强度对各指标的关联序为:新梢平均梢长新梢平均基径平均结果枝数结果枝平均坐果数平均新梢数平均开花枝数。     

High-pruning of European beech (Fagus sylvatica L.) and pedunculate oak (Quercus robur L.): work efficiency for target pruning as a function of tree species,pruning height,branch characteristics,pole saw type and operator

The objective of this study was to establish an operational model of productive work time per tree (work efficiency) for high-pruning of young European beech and pedunculate oak depending on tree species, pruning height, branch characteristics, pole saw type and operator. The final model included all of these independent variables with branch characteristics specified in terms of number of live branches and cross-sectional area of the thickest branch at the cut. Work time increased with increasing values of each of the three numeric variables. For a given pruning height the size of the largest branch was for all practical purposes more influential than the number of live branches. Beech took 28% longer to prune than oak. The German Ergo-Schnitt saw was 21% slower than the Japanese Silky Hayauchi saw. The variation in worker performance within our study was larger than that attributed to tree species and pruning equipment.     

杨树修枝理论和技术研究进展

杨树修枝是杨树速生丰产后期经营管理中一项重要的措施,本文综述了修枝对杨树生长、材质以及林下经济的影响。修枝对杨树树高、材积生长量的影响因树种、立地、修枝强度的不同规律不同;修枝会降低胸径的生长量,提高萌枝数量,但可以提高材质。修枝对材质的影响表现在尖削度减小、节子减少、形数和形率增加等。修枝可以增强林下作物光合作用,促进林下植物生长,提高产量;实践中,修枝强度、起始年龄、修枝季节应因树种而异。目前,对于杨树修枝的研究多为短期的、单方面的,系统综合研究尚需进一步加强。     

四川桤木无性系采穗圃修枝与施肥试验初报

为提高四川桤木无性系采穗圃穗务产量,对其无性系进行了修枝与施肥试验,试验表明：在无性系定杆150cm高时,将其抽发的侧枝进行短截修剪,修剪强度以轻、中短截效果最佳,可显著提高无性系穗条产量,在无性系定杆120cm高时,施用氮肥可显著提高无性系穗条产量?