林分密度和立地对油松人工林生长的影响

以北京山区25块油松人工林样地为研究对象,调查了40年生油松人工林在不同林分密度和立地条件下的生长状况,建立了林分密度与平均胸径、平均树高、平均冠幅和单木材积之间的回归方程,相关指数都在0.9以上;以样地平均优势木的解析材料确定40年生优势木树高,按单项立地因子实际分布区间分组,进行方差分析、差异显著性检验、多重比较。结果表明:随着林分密度的增大,平均胸径、平均树高、平均冠幅、单木材积逐渐减小;北京山区40年生油松人工林密度应控制在1 500株/hm2以下;明确了北京山区油松人工林生长与立地因子的关系,初步确定了油松人工林适宜的立地条件为:低山、阴坡、有效土层厚度(A+B层)45cm以上。     

Effects of site management treatments on growth of six-year-old, second-rotation Chinese fir (Cunninghamia lanceolata) plantations

The effects of five different site management treatments on the productivity of a six-year-old and secondrotation Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations planted after harvesting a 29-year-old and first-rotation Chinese fir plantation in Xiayang State Forest Farm, Nanping, Fujian Province, were studied. Results showed that the Chinese fir grew best on plots treated with the double slash treatment (BL₃), followed by the whole tree harvest (BL₁) and the slash burning treatment (SB), and poorest on treatment BL₂ (normal slash retention) and BL₀ (removal of all organic matter aboveground). The site index of the second rotation Chinese fir plantations in BL₃ and BL₀ treatments increased by 0.56 and 0.27, respectively, compared with the first rotation, and decreased in the rest of the three treatments. Compared with the first rotation, the site index of the second rotation treated with BL₁, SB and BL₂ treatments decreased by 0.39, 0.45 and 0.63, respectively. Differences among the treatments were not statistically significant. __________ Translated from Scientia Silvae Sinicae, 2006, 42(11): 47–51 [译自: 林业科学]     

不同立地条件下休宁倭竹生长差异分析

在安徽省绩溪县和休宁县按照随机抽样的方法,设置了15个样方调查休宁倭竹的竹高、地径、叶片长度、叶片宽度和鞭径等生长指标,以及日照和湿度等立地因子。分析这些生长指标和立地条件的关系,结果表明：日照和湿度是影响休宁倭竹生长的关键立地因子,日照对休宁倭竹竹高和叶片生长的影响较大,湿度对休宁倭竹根系生长的影响较大,多重比较结果差异显著,同时日照条件对休宁倭竹叶片的变异性影响较大。因此,休宁倭竹应在光照条件好、土壤湿润的立地条件下栽植。     

不同立地条件下水曲柳人工林生长状况的初步研究

不同立地条件的水曲柳人工幼龄林生长指标的调查结果表明:缓坡造林,8 a生胸径最大值为6.0 cm,树高最大值为6.5 m;轻微水湿地造林,经2次施肥后,12 a生时平均胸径、平均枝下高生长量较缓坡造林的8 a生水曲柳仅具有微弱生长优势,平均树高、平均冠幅和平均枝下高低于8 a生缓坡水曲柳幼龄林;农耕地10 a生水曲柳人工幼龄林平均树高为4.50 m,为其他立地的150%,最大值为6.8 m,胸径最大值为7.3 cm,单位面积立木蓄积为其他立地的158.3%。水曲柳造林后第四年开始,胸径、树高、材积生长较快,胸径连年生长量由0.65 cm增至0.80 cm以上;树高生长量在4~6 a增长最大,连年生长量达1.00 m,平均生长量也持续在0.60 m以上;材积平均生长量、连年生长量自第四年开始,增幅较大,第六年连年生长量为第五年的1.92倍。     

区域和立地条件对麻栎生长的影响

本文系统地研究了区域和立地条件对麻栎林生长的影响,提出了麻栎生长的最佳适生区。麻栎林的生产力随海拔和纬度的增加呈递减趋势,麻栎林林分生物生产力具有经向、纬向和垂直向的变化规律。麻栎生长在阳坡20°以下、山中腹小于30°的沙壤土最好。     

不同基质与栽培措施对霍山石斛生长的影响

研究了不同基质和栽培措施下,霍山石斛组培苗在温室内的生长情况。结果表明,在9种不同基质和4种不同栽培措施的处理下,霍山石斛的各项生长指标有显著差异(P=0.000 1<0.01)。(1)炼苗成活率:以C-f组合最高(96%),其次是C-g组合和D-f组合(92%)。(2)茎生长:新茎数以C-f组合为最高(36枝);茎高各处理差异不大,以C-f组最高(13.5 mm);茎粗以C-f和D-h组合表现较好。(3)根生长:新根数以C-f组合为最多(38.1根),其次C-g组合(36.7根);根长以C-g组合为最高(17 mm),其次C-d组合(16.9 mm);根粗以C-h和D-f组合(1.6 mm)为好。(4)苗木根茎比:以基质C-d组合为最高,其次是D-d、B-d。因此,在培育霍山石斛组培苗时,采取C处理(包根、喷施JT溶液)和f基质(树皮碎屑、米心石质量比2∶1)是提高炼苗成活率和促进苗木健康生长的最佳栽培措施。     

Effects of microsite conditions and early pruning on growth and health status of holm oak plantations in Central-Western Spain

New Forests - The aim of this study was to examine the influences of early pruning and microsite conditions on the growth and health status of holm oak plantations on former agricultural land in...     

水分胁迫对栓皮栎幼苗生理特性及生长的影响

通过盆栽实验，研究了在不同的水分条件下栓皮栎幼苗生理特性的变化和苗木生长量的变化。研究表明，在水分胁迫初期，随土壤含水量的降低，栓皮栎叶片的净光合速率、蒸腾速率下降，而水分利用效率提高。在水分胁迫末期，由于长期的干旱胁迫，水分条件最差的一组苗木已干枯死亡，土壤含水量从38．123％下降到20．323％时，净光合速率和蒸腾速率均下降，水分利用效率也下降。随着土壤含水量的降低，苗高、地径和生物量均有下降的趋势，其中生物量下降的幅度最大。     

长白落叶松工业纤维林立地控制技术的研究

通过室外样地调查和室内木材材性分析及硫酸盐制浆实验,研究了不同立地条件下长白落叶松工业纤维林的生长过程、木材纤维特性、化学组成、物理性质和制浆特点,指出了立地条件对林分生长、木材纤维含量、纤维长度、纤维长宽比、得浆率、纸浆物理强度的影响。结果表明,长白落叶松工业纤维林生长最佳的立地条件是山地下部Ⅰ、Ⅱ地位级。立地条件对木材材性和纸浆特性有直接影响。在研究的林分密度和立地条件范围内,立地条件越差,木材纤维含量越少,纤维长度越短,纤维长宽比越小,1%NaOH提取物越多。而且这种现象有随林龄增长而加重的趋势。但立地条件对得浆率和纸浆的物理强度影响不明显。综合林分生长和木材材性,长白落叶松工业纤维林的培育最好在山地下部Ⅰ地位级和Ⅱ地位级的立地条件下进行。表4参17。     

Effects site conditions on industrial fiber plantations of Lar/x olgensis

Plot sampling was conducted in the second cultivation areas ofLarix olgensis in Heilongjiang Province, China. By analyzing plot investigation data, wood properties, and kraft pulps of 840 plots and 248 sample trees in industrial plantations of L. olgensis on different sites, we examined the growth process of L. olgensis industrial plantation with suitable structure, the wood fiber feature, chemical composition, physical performance and pulp characteristics. It is suggested that site conditions have major effects on plantation growth, fiber contains, fiber length, rate between fiber length and fiber width, pulping rate and pulp physics intensity. The best site for L. olgensis industrial plantation growth is site class Ⅰ and site class Ⅱ, which are on lower locations. Site condition has an obvious influence on the wood characteristics. Within the range of site conditions and stand densities studied, the worse the site condition, the less the fiber contains, the shorter the fiber length, and the more the 1% NaOH extraction. This kind of relationship becomes more obvious as stand age increases. However, the influence of site condition on pulping rate and pulp physics intensity is not obvious. The result provides theoretical base for cultivation of industrial fiber plantation of L. olgensis.     

GROWTH OF MONGOLIAN OAK

GRANDPERIODOFGRoWTHMongolianoak(Q.mongolica)wasamaintreespeciesofthesecondaryforestsinHeilongjiangProvince.Thesecondaryforestswereforn1edfromthevirginforestwhichwasrepeatlydestroyed.ThatdecidedthatmostofmongolianoaksoriginatedfromthestumpsproutingforthenaturalstandsItwasreportedthatalmostalltheoaktrees1essthan2oyearso1dinthenaturalstandsweresproutingorigin,buttheseed1ingsincreasedwiththeirageintheeasternHeilongiiangProvince(ChenBoxianetal,l965).Thegrandperiodsofgrowthoftheoakwithdiff…     

洞庭湖区不同立地杨树生长规律研究

于洞庭湖区的岳阳市君山区、沅江市、临澧县、常德市鼎城区,选择2008年春造林的杨树人工林,按平原、滩地、丘陵平地与丘陵坡地4种立地类型设立标准样地,对洞庭湖区不同立地杨树的生长规律进行研究。结果表明:在平原、滩地、丘陵平地、丘陵坡地等4种立地,6年生杨树林的年均树高生长量分别为2.8m、2.3 m、2.6 m、1.5 m,年均胸径生长量分别为2.6 cm、2.6 cm、2.3 cm、1.9 cm,年均单株材积生长量分别为0.024 0 m3、0.018 0 m3、0.018 0 m3、0.006 3 m3,年均单位面积蓄积生长量分别为20.0 m3/hm2、15.5m3/hm2、15.5 m3/hm2、7.8 m3/hm2;4种立地以平原地的杨树生长最好,并且立地条件越好,杨树进入快速生长期也越早;在平原,6年生杨树的胸径生长已经因林分过密而放缓,但树高、单株材积、单位面积蓄积生长量都还处于快速生长期。     

不同栽培基质对沙枣生长性状及生理指标的影响

采用5种栽培基质对沙枣的生长性状及有关生理指标进行研究,结果表明:有机肥:沙:盐碱土=1:1:1的配比较为适合营造以生物量为主要指标的沙枣饲料林,可以显著增加产量;有机肥:沙:盐碱土=1:2:1的配比适合营造沙枣生态林,可以正常生长。沙枣具有较高的耐盐碱特性。     

Influence of site in the wood quality of Eucalyptus in plantations in Brazil

Genetic materials interact with the environment in specific ways, therefore their responses in wood need to be better understood. The present study sought to evaluate the influence of different climatic conditions in Minas Gerais, Brazil on Eucalyptus grandis × Eucalyptus urophylla wood. Two six-year-old clones were cultivated in Belo Oriente, Ferros, Santa Bárbara, Itabira and Peçanha. Five trees from each clone were sampled from the base to top direction. Wood density, heartwood/sapwood ratio, vessels, fibres, and extractive and lignin contents were determined, as well as their correlation with environmental variables. Vessel diameters, heartwood/sapwood ratio, and extractive and lignin contents all increased due to higher water availability in Santa Bárbara and Itabira. In both genetic materials, the variables linked to growth and wood quality were related to environmental factors.     

不同立地因子与麻栎生长的相关分析

通过对麻栎适生条件的相关分析,认为影响麻栎生长的主要立地因子是坡向、海拔、土层厚度、坡度,并以生长在S坡、坡度20°以下、土层厚度30cm的沙壤土为最佳。     

立地条件与毛竹竹材密度和纤维形态关系初探

依据江西32块不同立地条件样地的调查材料,研究分析了立地条件对毛竹竹材密度和纤维形态的影响,研究结果表明:竹材的纤维长度主要是受海拔和速效N的影响,随海拔升高而减小,速效N在4.0%~6.0%时纤维长度最短;其次有机质含量为3%~5%和粘土纤维长度最短,而壤土最长。纤维宽度主要受速效P、坡位和速效K的影响,且速效P和坡位对纤维宽度影响达显著差异水平。纤维长宽比在不同立地条件下比较稳定,受立地因子影响较小。坡位对竹材基本密度影响达显著差异水平,上坡和海拔500~800 m时基本密度最大,全N、速效N和有机质含量增高及速效K含量降低,而基本密度增大。影响竹材气干密度的主导因子依次为速效K、速效P和腐殖质厚,气干密度和基本密度有同方向的变化趋势。     

北美橡树嫁接育苗试验

采集适合湘南地区栽培的北方红栎、猩红栎、娜塔栎、沼生栗栎和柳栎等北美橡树品种的枝条作为接穗,以麻栎实生苗为砧木,开展北美橡树嫁接育苗试验。试验结果为:就嫁接成活率而言,北方红栎的最高,为99.34%;其次是猩红栎的,为98.14%;沼生栗栎和柳栎的分别为94.15%和92.86%;娜塔栎的最低,为76.09%;各品种嫁接成活率排序为北方红栎>猩红栎>沼生栗栎>柳栎>娜塔栎。就保存率而言,北方红栎的最高,为89.40%;其次是柳栎的,为71.79%;沼生栗栎和猩红栎的分别为39.13%和32.28%;娜塔栎的最低,为29.29%;各品种嫁接苗保存率排序为北方红栎>柳栎>沼生栗栎>猩红栎>娜塔栎。不同北美橡树品种间苗高、地径均存在显著差异。就苗高而言,猩红栎及娜塔栎的较高,猩红栎的为149.08cm,娜塔栎的为140.88cm,两者间无显著性差异;北方红栎、沼生栗栎、柳栎的较低,北方红栎的为106.44cm,沼生栗栎的为95.20cm,柳栎的为110.00cm,且三者苗高生长均显著劣于猩红栎及娜塔莉。就地径而言,北方红栎的最大,为16.36mm,且显著优于其他品种;猩红栎与娜塔栎间无显著差异,其地径分别为13.28mm和11.87mm;沼生栗栎与柳栎间无显著差异,其地径分别为9.17mm和8.77mm,且两者均显著劣于其他品种。     

Effects of oak root pruning in forest nurseries on potential pathogen infections

Despite the general practice of root pruning, little is known about the potential impact of reducing shoot/root systems of oak seedlings in this way on their future susceptibility to pathogens, for example Cylindrocarpon spp., Fusarium spp., Ilyonectria spp., Pythium spp. Phytophthora spp. or Rhizoctonia spp. In this study, root‐pruned and non‐pruned seedlings of Quercus robur grown under controlled conditions were inoculated with aggressive and less‐aggressive pathogens. Results indicated, in contrast to our initial assumption, that pathogens significantly reduced lateral root biomass more in non‐pruned seedlings, the extent of the response depending on the pathogens species. In response to pathogen pressure, pruned seedlings tended to attain a higher dry stem mass fraction, but lower dry leaf mass fraction. Pathogens also suppressed leaf mass in total root dry mass fraction (dry leaf mass/total root dry mass ratio, in g × g^?1) more in pruned than in non‐pruned seedlings. These results suggest differences in growth between non‐pruned and pruned seedlings in response to pathogen stress. In nurseries, root pruning of oak trees may enhance the reduction in leaf mass in lateral roots mass fraction resulting from pathogen infections, which may decrease seedling quality. It is therefore important to ensure a low level of inoculum of soil‐borne pathogens to minimize the risk of seedling infection.     

蒸汽爆破预处理对柞木微观结构的影响

对采用0.4MPa压力进行蒸汽爆破预处理及干燥的柞木板材,通过扫描电子显微镜对试件的微观结构进行观察,并对经过爆破处理和未爆破处理的试件的微观结构进行分析比较.试验表明,柞木经爆破处理后管胞纹孔边缘开裂,射线薄壁细胞产生细小的裂隙,导管内的侵填体剥落,这些对木材的力学强度没有太大的影响,但使得木材的渗透性得以提高.