乐昌含笑人工林的土壤肥力和涵养水源功能研究

通过对乐昌含笑和杉木人工林生物量和土壤肥力的调查,进行乐昌含笑人工林培肥土壤和涵养水源功能的研究,结果表明:营造乐昌含笑人工林后林地土壤水稳性团聚体含量增加,团聚体的稳定性增强,容重降低,总孔隙度增加,林地土壤结构、孔隙和养分状况得到不同程度的改善,乐昌含笑人工林具有比杉木林更好的培肥土壤功能;乐昌含笑叶的最大持水率明显高于杉木叶,其林分地上部分最大持水量是杉木林的1.14倍,同时由于乐昌含笑林土壤结构及孔隙状况的改善,林地蓄水能力增强,使得乐昌含笑人工林表现出比杉木林更好的水源涵养功能。     

Behavior of four broad-leaved tree species used to revegetate eroded granite hill slopes

Information on primary growth behavior after planting is required for mixed-plantation revegetation using broad-leaved species. To estimate primary growth, especially from the perspective of crown coverage and changing growth rates, we examined the growth and survival of four broad-leaved species that are frequently used in erosion-control plantations in Japan. The species studied were Myrica rubra Sieb. et Zucc., Alnus pendula Matsum., Quercus glauca Thunb., and Q. serrata Thunb. The survival, height, and basal diameter of planted trees were measured over a 4-year period, and crown area was calculated over a 3-year period. We found a negative relationship between relative growth rate (RGR) and survival rate, suggesting that fast growth may be fatal when resources are severely limited. The relative height growth rate (RHGR) of A. pendula was especially high during the early period of the study (1997–1999) and then drastically declined, whereas the opposite tendency was observed in Q. glauca. The results of stem allometry analyses conformed to the specific relationships between height growth and diameter growth of the four species; increases in stem thickness based on height increments were smaller in the pioneer species A. pendula. Between-species differences in coverage per planted tree (mean crown area multiplied by survival rate) were small as a result of the negative relationship between coverage area and survival rate.     

长白落叶松工业用材林经营模拟研究

通过对长白落叶松不同立地等级和经营密度的林分进行经营模拟研究发现：在即时间伐的情况下，木材径级与初始造林密度没有相关关系，与立地等级关系极为显著，低密度经营措施不能有效增加木材径级；问伐和主伐收获总量随着密度的增加，增幅差异不明显；如果考虑营林投资的时间成本价值。长白落叶松人工用材林的培育周期不应超过60年。     

福建桉树人工林材积表和蓄积量表编制的研究

通过对桉树人工林83块标准地和164株样木进行调查,选择V=aDbHc和V=aDb方程并进行多方程拟合对比,编制桉树人工林二元材积表和一元材积表,结果表明:该表可在森林调查中应用,且误差小,能满足林业生产上的精度要求。同时为提高林分蓄积量的测定效率,选择林分平均高和断面积为辅助变量,建立桉树人工林林分蓄积量预估模型,该模型经检验适用,可用于林业生产实践。     

Response of <Emphasis Type="Italic">Pinus pseudostrobus</Emphasis> Lindl. to fertile growing medium and tephra-layer depth under greenhouse conditions

Major disturbances that remove vegetation cover create conditions that differ greatly from those in adjacent forests. In volcanic areas, tephra deposition can be a major disturbance that eliminates vegetation cover and creates a barrier for plant establishment. The eruption of the Paricutín volcano, in Michoacán, México, from 1943 to 1952, created large tephra deposits adjacent to forest stands. Many of these deposits still lack native vegetation and understanding of the limiting factors for establishment of native tree species is necessary to restore these areas. Pinus pseudostrobus early growth in response to the amount of fertile growing medium on top of a variable-depth tephra layer was evaluated in a greenhouse experiment. Increasing amounts of fertile growing medium increased height of 28-week-old plants (no growing medium = 5.5 cm tall ±1.8 cm, 3 cm of growing medium = 21.2 ± 4.6 cm and 6 cm of growing medium 24.8 ± 4.4 cm). Other variables showed the same trend (diameter, number of fascicles, belowground biomass and aboveground biomass). Our results suggest that P. pseudostrobus establishment in tephra covered areas will depend on the accumulation of a fertile layer of more than 3 cm in thickness.     

青枯菌对桉树及非寄主树木根部吸附和侵入的比较

通过接种青枯菌与非病原的大肠杆菌,对2个桉树无性系和1种非寄主树木的根表吸附菌量及根内含菌量进行测定.结果表明:青枯菌对感病寄主根表的吸附量多于对抗病寄主和非寄主根表的吸附量,对感病寄主根部的侵入量多于对抗病寄主但少于对非寄主根部的侵入量;病原菌较非病原菌对感病寄主根表的吸附量大,但二者对感病寄主根部的侵入量则依据根部伤口的有无而互有高低.青枯菌接种24 h内,感病寄主根表吸附菌量和根内含菌量呈上升趋势,在抗病寄主及非寄主根表的吸附菌量和根内含菌量却呈下降趋势.从统计学上看,青枯菌对寄主根部的吸附和侵入都显示出了一定的选择性,但由于病原细菌能够大量地吸附和侵入抗病寄主和非寄主根部,非病原细菌也能够大量地吸附和侵入桉树根部,因此这种选择性的生物学意义不大,青枯菌对桉树根表没有表现出明显的识别行为.     

福建柏与萌芽杉木混交林经营效果的调查研究

安溪半林林场在杉木迹地上营造福建柏,并选留杉木萌芽条形成福建柏杉木混交林,不论混交林经营密度大小,福建柏生长均比纯林好。大、中密度组的福建柏生长比萌芽杉木快,但在小密度组则相反。萌芽杉木在大、中密度条件下,生长不如同龄纯林,在小密度条件下的平均树高、胸径是纯林的140.2%和148.2%。说明福建柏与萌芽杉木混交培育方式是成功的,但到15年生以后,经营密度以1 500株.hm-2左右,混交比例6∶4为宜。     

Selection, propagation and cultivation of Pinus massoniana clones for pulp use

Based on the growth, wood property of the ortets, and rooting abilities of cuttings, 32 Pinus massoniana clones for pulp use were selected from forests of superior provenance, mixed families, and progeny test of seed orchard by two-step selection. The average height and DBH growth of three-year-old clones were 28.6% and 16.7%, respectively, higher than those from seedlings, and average gain of wood density reached 8.7%. Rooting rate of all these clones was over 80%, 28% higher than the clones selected by a single step. A cutting orchard of 0.33 hm² on the hillside was constructed to intensively produce cuttings according to the tests on construction methods, pruning, and fertilization. A total of 50,000 grade I, 37,500 grade II, and 62,500 grade III cuttings were collected per hectare of this cutting orchard each time, and were cut three times each year. With all the above techniques, 48 hm² of clonal forests for pulp use of those clones had been planted in five places in Fujian Province. Container stecklings are more likely to increase the planting survival rate. __________ Translated from Scientia Silvae Sinicae, 2004, 40(1): 64–69 [译自: 林业科学]     

Performance and yield of 14 eucalypt species on Imperata cylindrica (L.) Beauv. grassland 3 years after planting

A species trial with 14 eucalypt species with randomized complete blocks design was planted on Imperata cylindrica dominated grassland in South Kalimantan, Indonesia in January 1987. The site was prepared mechanically. No fertilizers were used. At the age of three years E. camaldulensis had clearly the highest survival rate (95%) and mean annual increment (5.9 m³ha^–1a^–1) compared with the other species tried. It was followed by E. urophylla, E. deglupta, E. pellita, E. tereticornis, E. alba, E. torelliana, E. intermedia, E. grandis and E. pilularis. Four other species, E. phaeotricha, E. resinifera, E. cloeziana and E. microcorys died either in the nursery or immediately after planting. All the eucalypts tried had narrow crowns and open canopies. It is suggested that eucalypts are not recommendable for grassland reforestation under minimum plantation tending. Effects of intensive weeding, spacing, fertilizing and performance in second rotation or mixed stands should be tested to elaborate the suitability of eucalypts on grasslands.     

Intratree Variability of Cleavage Resistance of Chinese Fir from Plantation

INTRODUCTION Chinese fir (Cunninghamia lanceolata) is a very important timber species in the southern China (Shi Jisen et al. 1987). It is good, fast-growing, and exempts from serious plant diseases. Its plantation is big in terms of size in the South of China and its storage stock is very rich, which is about 20% of the national commodity wood (Zhou Shuangquan et al. 2000). And the lumber becomes mainly commercial construction materials in China because of straight grain, light and so…