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研究了不同栽植密度对沙枣幼苗的苗高、地径以及生物量的影响。结果表明,5种栽植密度下,沙枣幼苗的苗高生长量、地径生长量的积累在不同生长季表现出明显的差别：（1）在栽植密度为1 m×1.5 m时2年生沙枣苗的苗高、地径、生物量积累都高于其他密度,在密度为2 m×2 m时的苗高生长量、地径生长量、生物量最低。（2）不同密度下沙枣苗的含水率依次是1.5 m×2 m〉1 m×1.5 m〉1.5 m×1.5 m〉2 m×2 m〉1 m×1 m;根冠比依次是1 m×1 m〉1.5 m×1.5 m〉2 m×2 m〉1 m×1.5 m〉1.5 m×2 m。（3）不同密度下各营养器官的分配存在差异。总体而言,单株苗木各营养器官所占百分率的平均值依次为叶〉干〉根〉枝。 相似文献
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以小密度667株.hm-2在3个立地指数22、24和26条件下,16年生林分生长结论为：（1）立地指数22、24和26达到中大径材培育目标的时间和年均生长量指标分别为10 a、8 a和7 a,年均生长量分别为21.6、27.2和31.1m3.hm2。（2）胸径生长和分布：胸径生长量随着时间的推移逐年变小,前2 a胸径每年生长超过4 cm,第3年超过2cm,4~6年超过1cm,以后越来越小,但在16 a的观测过程中,每年都稳定超过0.4 cm;在生长前期,2年生时,只有2~3个径阶;到6年生时,径阶增加到7个;到16年生时,径阶增加到10~11个（。3）平均高生长量随着时间的推移逐年变小,前3 a树高生长均超过3 m;第4~5年超过2 m,5~10 a超过1 m,以后越来越小,但在16年的观测过程中,每年稳定超过0.6 m。（4）蓄积量生长的高峰值都出现在第4年,且峰值都很大,指数22、24和26的峰值分别为43.3、52.23和54.69 m3.hm-2,为平均生长量的2倍,峰值过后年生长量迅速下降,第1年下降超过10 m3.hm-2,第2年下降7 m3.hm-2,以后逐年下降,但降幅收窄;指数22、24和26的连年与平均蓄积生长曲线的交叉点均出现在第7年。 相似文献
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早期在杉木伴生下的闽楠人工林生长规律研究 总被引：2，自引：1，他引：1
对早期在杉木伴生下的28年生的闽楠人工林生长规律进行了研究,结果表明:早期以杉木为伴生树种的闽楠人工林,无论是树高、胸径、材积生长都明显高于闽楠纯林,28年生时平均木的单株材积达到0.24628 m3,比闽楠纯林增加100.9%。其胸径连年生长量最大值出现在8~10年生时,峰值为1.02 cm.a-1,连年生长量在0.8 cm.a-1以上的年份有14a;树高连年生长量在10~12年生时最大,峰值为1.07 m.a-1,4~16年生时生长量都保持在0.8 m.a-1以上。闽楠纯林树高总生长量只有15.89 m,连年生长量在8~10年生时最大,峰值为0.95 m.a-1,比以杉木为伴生树种的闽楠要小。 相似文献
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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。 相似文献
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白龙江林区华北落叶松人工林生长过程研究 总被引：10，自引：1，他引：10
对白龙江林区20年生华北落叶松人工林进行了33块样地调查，并对35株样本进行了树干解析，以研究其生长过程。结果表明：（1）6－10年分别是胸径和树高的速生期；胸径高峰值出现在第8年（1．11cm），树高高峰值出现在第7年（0．87m)；胸径和树高的平均生长量和连年生长量分别相交于14年。（2）建立了华北落叶松人工林胸径、树高、材积、生长率、形数的数学模型，并经对胸径、树高、材积生长进行模拟得出，它们符合理查得（Richards)生长曲线。（3）18年生材积生长量比云杉、华山松、油松3个树种的材积生长量高2倍以上，生长速度的次序为：落叶松＞华山松＞油松＞云杉。 相似文献
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坡向与造林密度对刨花润楠幼林生长的影响 总被引：2，自引：1，他引：1
在福建省华安葛山国有林场,通过对不同坡向和2种造林密度的10年生刨花润楠林分生长量调查分析,结果表明:不同坡向对刨花润楠树高和胸径生长有显著影响,以东北坡的刨花润楠生长量最大,胸径达到8.1 cm,树高9.1 m;其次为西坡、北坡、南坡;东坡最小。种植密度对刨花润楠生长有显著影响,适当的提高造林密度能够促进刨花润楠的生长。 相似文献
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尾巨桉2种留萌密度的幼林生长比较 总被引：2，自引：0，他引：2
为探讨留萌密度对尾巨桉（Eucalyptus urophlla×E.grandis）萌芽林生长量的影响,分4个生长时期（0.3年生,1.4年生,2.3年生和3.3年生）对广西东门林场尾巨桉2种留萌密度（留萌1株和留萌2株）的萌芽林的生长量进行了调查研究.结果表明：2种留萌密度下桉树萌芽林的胸径,树高及林分蓄积量均有不同程度的差异.留萌1株的萌芽林平均树高和平均胸径均显著高于留萌2株的萌芽林,而且这种差异会随林龄的增加而增加;而留萌2株的林分蓄积量表现出高于留萌1株的萌芽林的态势,但差异随着林龄的增加而减小. 相似文献
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以1994年种植在广东省龙眼洞林场的马占相思人工林为材料,调查5,10和15a生的树高、胸径和蓄积量,研究海拔和造林密度对生长量的影响。结果表明,海拔（0～500mm）对马占相思胸径生长无显著影响,但对5a生的树高、5和10a生的蓄积量有显著影响,其中250m〈海拔≤500m时的林分蓄积量最大;3种造林密度（800,1335和1998株／hm^2）对树高、胸径和蓄积量有较大影响,以造林密度为1335彬hm^2的林分蓄积量增长最快。林分内存在不同程度的海拔与造林密度交互作用,这种互作对胸径和蓄积量的影响逐年增强．但在15a生时对树高的影响已．不鼹薯． 相似文献
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Büntgen U Frank DC Kaczka RJ Verstege A Zwijacz-Kozica T Esper J 《Tree physiology》2007,27(5):689-702
We analyzed growth responses to climate of 24 tree-ring width and four maximum latewood density chronologies from the greater Tatra region in Poland and Slovakia. This network comprises 1183 ring-width and 153 density measurement series from four conifer species (Picea abies (L.) Karst., Larix decidua Mill., Abies alba (L.) Karst., and Pinus mugo (L.)) between 800 and 1550 m a.s.l. Individual spline detrending was used to retain annual to multi-decadal scale climate information in the data. Twentieth century temperature and precipitation data from 16 grid-boxes covering the 48-50 degrees N and 19-21 degrees E region were used for comparison. The network was analyzed to assess growth responses to climate as a function of species, elevation, parameter, frequency and site ecology. Twenty ring-width chronologies significantly correlated (P<0.05) with June-July temperatures, whereas the latewood density chronologies were correlated with the April-September temperatures. Climatic effects of the previous-year summer generally did not significantly influence ring formation, whereas site elevation and frequency of growth variations (i.e., inter-annual and decadal) were significant variables in explaining growth response to climate. Response to precipitation increased with decreasing elevation. Correlations between summer temperatures and annual growth rates were lower for Larix decidua than for Picea abies. Principal component analysis identified five dominant eigenvectors that express somewhat contrasting climatic signals. The first principal component contained highest loadings from 11 Picea abies ring-width chronologies and one Pinus mugo ring-width chronology and explained 42% of the network's variance. The mean of these 12 high-elevation chronologies was significantly correlated at 0.62 with June-July temperatures, whereas the mean of three latewood density chronologies, which loaded most strongly on the fourth principal component, significantly correlated at 0.69 with April-September temperatures (P<0.001 over the 1901-2002 period in both cases). These groupings allow for a robust estimation of June-July (1661-2004) and April-September (1709-2004) temperatures, respectively. Comparison with reconstructions from the Alps and Central Europe supports the general rule of the dominant influence of growing season temperature on high-elevation forest growth. 相似文献
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To provide data and methods for analyzing stem mechanics, we investigated bending, density and growth characteristics of 207 specimens of fresh wood from different heights and radial positions of the stem of one mature Norway spruce (Picea abies L. Karst.) tree. From the shape of each stress-strain curve, which was calculated from bending tests that accounted for shear deformation, we determined the modulus of elasticity (MOE), the modulus of rupture (MOR), the completeness of the material, an idealized stress-strain curve and the work involved in bending. In general, all mechanical properties increased with distance from the pith, with values in the ranges of 5.7-18 GPa for MOE, 23-90 MPa for MOR and 370-630 and 430-1100 kg m(-3) for dry and fresh wood densities, respectively. The first three properties generally decreased with stem height, whereas fresh wood density increased. Multiple regression equations were calculated, relating MOR, MOE and dry wood density to growth properties. We applied these equations to the growth of the entire stem and considered the annual rings as superimposed cylindrical shells, resulting in stem-section values of MOE, MOR and dry and fresh densities as a function of stem height and cambial age. The standing tree exhibits an inner stem structure that is well designed for bending, especially at a mature stage. 相似文献
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We compared sap-flux-scaled, mean, canopy stomatal conductance (GS) between Picea abies (L.) Karst. in Sweden and Pinus taeda (L.) in North Carolina, both growing on nutritionally poor soils. Stomatal conductance of Picea abies was approximately half that of Pinus taeda and the sensitivity of GS in Picea abies to vapor pressure deficit (D) was lower than in Pinus taeda. Optimal fertilization increased leaf area index (L) two- and threefold in Pinus taeda and Picea abies, respectively, regardless of whether irrigation was increased. Although it increased L, fertilization did not increase GS in Picea abies unless irrigation was also provided. In Pinus taeda growing on coarse, sandy soils, the doubling of L in response to fertilization reduced GS sharply unless irrigation was also provided. The reduction in GS with fertilization in the absence of irrigation resulted from the production of fine roots with low saturated hydraulic conductivity. When Pinus taeda received both fertilization and irrigation, the increase in L was accompanied by a large increase in GS. In Pinus taeda, a reference GS (defined as GS at D = 1 kPa; GSR) decreased in all treatments with decreasing volumetric soil water content (theta). In Picea abies, theta varied little within a treatment, but overall, GSR declined with theta, reaching lowest values when drought was imposed by the interception of precipitation. Despite the large difference in GS both between Picea abies and Pinus taeda and among treatments, stem growth was related to absorbed radiation, and stem growth response to treatment reflected mostly the changes in L. 相似文献
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补充光照对欧洲云杉苗木生长的影响 总被引：2，自引：0，他引：2
光周期具有抑制苗木早期休眠,延长其生长期的作用,具有促进欧洲云杉苗木生长的作用,其在形态指标和生物量上表现得极显著.欧洲云杉大棚育苗补充光照的完整技术可采用整夜补光,随着光强度的增加,苗木生长形状各指标呈渐增的趋势.光质以白光较好. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(4):304-316
Variation in radial increment at different stem heights was compared with stem volume increment and height increment using thinning experiments of Picea abies (L.) Karst. in southern Finland. The magnitude of growth variation was similar on trees from different crown classes and stand densities. However, there was higher autocorrelation in the codominant and intermediate trees and trees on dense plots. The relationship between short-term volume increment and radial increment variation at breast height was not affected by thinnings. While short-term growth variation was similar at different stem heights, some evidence was found for differences in medium-term variation between radial increment at breast height and volume increment. Height increment reacted to unfavourable climatic events later than radial and volume increment. Radial and volume increments were negatively correlated to temperature and positively correlated to precipitation of the current summer. Height increment was positively related to current early summer temperature, but negatively to temperature of the previous summer. 相似文献
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Differentiation of adventitious buds and somatic embryos from mature zygotic embryos of Picea sitchensis (Bong.) Carr. is described. Adventitious buds were formed on embryos pulse-treated with 250 microM benzyladenine for 2 h and cultured on medium lacking growth regulators. Buds were initiated at different frequencies and sites depending on when the BA-pulsed embryos were transferred to fresh culture medium. Embryogenic callus was formed when the zygotic embryos were cultured on medium containing 10 microM 2,4-dichlorophenoxyacetic acid and 5 microM benzyladenine. Although 50% of the embryos gave rise to embryogenic callus, only 20% of the callus continued to proliferate after subculture. Proliferation of new somatic embryos occurred from both the embryonic region and the suspensor region on previously formed somatic embryos. The pattern for development of adventitious buds and somatic embryos in Picea sitchensis is compared to that in Picea abies under similar culture conditions. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):87-96
Relationships between the crown density and growth of Norway spruce (Picea abies L. Karst.) stands are presented, after removal of the effects of major natural influences. Crown density was assessed annually from 1991 to 1996 on 569 monitoring plots comprising 40000 trees. Stand growth was determined from measurements of diameter and height in 1991 and 1996. Various models explaining mean crown density and annual growth of the stands as a function of natural factors, such as age and site index, were compared. The influence of the natural factors was then removed by recalculating crown density to residual values from one preferred model, and by recalculating growth to relative values given as a percentage of model predictions. Crown density and its residuals were positively correlated to growth. These relationships were weak in terms of their ability to explain variation (low R2). However, the various relationships consistently indicated that approximately 1% change in crown density corresponded to 1% change in growth. This relationship also included common spatial variation over Norway: a large part of south - east Norway had unexplained low crown density and unexplained low growth. Some other, smaller regional consistencies were also found. The study supports the use of crown density assessments and encourages the use of growth data in the search for major stress factors responsible for present forest condition. 相似文献