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在北亚热带地区太湖丘陵地引种美国红栎、南方红栎、北方红栎、柳叶栎、水栎的试验测定表明,上述国外栎树均能适应无锡气候,安全越冬、越夏,并正常生长发育,幼龄期尚未见明显病虫危害。3~5年生年均生长量为水栎>柳叶栎>南方红栎>红栎>北方红栎。秋叶变色期红栎最早,且红叶持续时间最长,柳叶栎变色较迟;水栎为半常绿型变色树种。从幼龄生长表现看,可选水栎、柳叶栎为丘陵地或低湿地优良景观用材树种,选红栎、南方红栎为城镇园林绿化观赏树种,在构建城市森林生态网络中扩大应用。北方红栎目前表现较差,尚待进一步观测。 相似文献
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北美栎树无性繁殖试验 总被引:3,自引:0,他引:3
对引种的北美栎树进行的扦插与嫁接繁殖试验结果表明:柳叶栎、纳塔栎和水栎1年生实生母树上的穗条,具有一定的扦插繁殖潜力。以200×10-6ABT6号处理纳塔栎插穗,生根率达52%;以100×10-6ABT6号处理水栎插穗,生根率达22.0%,以100×10-6ABT6号处理柳叶栎插穗,生根率达70%。但从6年生柳叶栎母树上采穗,并进行相同处理扦插后则不能生根,愈合率仅为7.2%。上述3种栎树的扦插生根能力顺序依次为柳叶栎>纳塔栎>水栎;全光喷雾设施的生根效果优于封闭式扦插。生根剂ABT6号处理优于NAA处理和NAA VB2处理。以麻栎为砧木,对纳塔栎、红栎和水栎等进行春季枝接后,60 d后的成活率分别为47.5%~61.2%,47.5%和13.3%~15.0%,且春季枝接的效果优于秋季芽接。 相似文献
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以15个纳塔栎优树、17个舒马栎优树和1个水栎优树自由授粉子代为材料,对造林2a时的树高、地径、冠幅、一级侧枝数等性状进行测定与分析,结果表明:(1)纳塔栎和舒马栎不同家系间各性状存在显著或极显著差异,其树高、地径、冠幅、一级侧枝数4个性状的家系间遗传力分别为0.68—0.96和0.56—0.85,家系选择具有较好的遗传改良潜力;(2)纳塔栎和舒马栎家系生长性状间均存在一定的正相关趋势。其中,纳塔栎树高与一级侧枝数,舒马栎树高与地径、树高与冠幅、地径与冠幅、树高与一级侧枝数的相关系数达显著或极显著水平,高、径生长量与树冠、分枝性状可以进行联合改良;(3)纳塔栎和舒马栎优树的树高和胸径与子代的树高和地径生长有一定的正相关趋势。其中,纳塔栎优树胸径与子代地径、优树树高与子代一级侧枝数、优树冠幅与子代地径间存在显著或极显著的正相关,但舒马栎优树冠幅与子代树高间存在显著的负相关;(4)根据造林2a子代测定林树高、地径、冠幅和一级侧枝数4个性状综合评价,纳塔栎N2,N4,N5,N8,N11,N13,N15,水栎W1和舒马栎S1,S4,S15,S16等12个家系的综合性状表现较优。 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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7种栎树的引种适应性研究 总被引:1,自引:0,他引:1
《山东林业科技》2015,(3)
为研究7种引种栎树在山东地区的适应性,本文对引进栎树进行了移栽成活率、生长量、抗病虫能力及耐寒性等进行了调查研究,结果发现,湿地栗栎和柳叶栎的移栽成活率较低,鲜红栎耐寒性稍差,美国灰栎易发生褐斑病和栎粉舟蛾,均不适宜在我省进行种植,而‘加州白栎’和大果栎不仅移栽成活率高,生长速度快且抗性强,是最适合在我省进行引种的栎树。 相似文献
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Initial growing space is of critical importance to growth and quality development of individual trees. We investigated how mortality, growth (diameter at breast height, total height), natural pruning (height to first dead and first live branch and branchiness) and stem and crown form of 24-year-old pedunculate oak (Quercus robur [L.]) and European ash (Fraxinus excelsior [L.]) were affected by initial spacing. Data were recorded from two replicate single-species Nelder wheels located in southern Germany with eight initial stocking regimes varying from 1,020 to 30,780 seedlings·ha -1 . Mortality substantially decreased with increasing initial growing space but significantly differed among the two species, averaging 59% and 15% for oak and ash plots, respectively. In contrast to oak, the low self-thinning rate found in the ash plots over the investigated study period resulted in a high number of smaller intermediate or suppressed trees, eventually retarding individual tree as well as overall stand development. As a result, oak gained greater stem dimensions throughout all initial spacing regimes and the average height of ash significantly increased with initial growing space. The survival of lower crown class ashes also appeared to accelerate self-pruning dynamics. In comparison to oak, we observed less dead and live primary branches as well as a smaller number of epicormic shoots along the first 6m of the lower stemof dominant and co-dominant ashes in all spacing regimes. Whereas stem form of both species was hardly affected by initial growing space, the percentage of brushy crowns significantly increased with initial spacing in oak and ash. Our findings suggest that initial stockings of ca. 12,000 seedlings per hectare in oak and 2,500 seedlings per hectare in ash will guarantee a sufficient number of at least 300 potential crop trees per hectare in pure oak and ash plantations at the end of the self-thinning phase, respectively. If the problem of epicormic shoots and inadequate self-pruning can be controlled with trainer species, the initial stocking may be reduced significantly in oak. 相似文献
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[目的]研究不同强度采伐下马尾松的生长动态,筛选适宜的采伐强度,为马尾松人工林近自然经营提供技术支撑。[方法]2007年10月在14年生马尾松人工林(保存密度1 100株·hm~(-2))内进行采伐试验,设置4个采伐强度,即保留密度分别为225、300、375、450株·hm~(-2),以不采伐为对照;其后,自2008年开始连续8 a,每2 a测定1次马尾松的胸径、树高、枝下高和冠面积等生长指标,并计算单株材积和林分蓄积量,应用方差分析和Duncan多重比较分析生长指标对不同采伐强度的动态响应。[结果]表明:采伐强度显著影响林分生长,其中,林分平均胸径、单株材积、冠面积的年均增长量随保留密度增大而减小,但均显著高于对照(P0.05)。采伐后第1 3年,马尾松冠面积增长量显著高于采伐后期,胸径则在采伐后第3 5年最高,而不同采伐强度对林分树高生长影响不明显。保留密度显著影响林分枝下高和蓄积量的动态变化,其年均增长量随密度增大而递增。5个处理间林分蓄积年均增长量的差异随林龄的增大而逐渐缩小。[结论]马尾松人工林生长对不同强度采伐的动态响应以树冠最敏感,冠面积首先陡然增大,进而引起胸径的快速生长。树高和枝下高在采伐后年均增量变化相对平稳。4个采伐强度均显著促进单株材积生长,而仅保留密度为225株·hm~(-2)的采伐对林分蓄积增长量影响显著。综合比较林分的单株材积和林分蓄积连年增长量,建议在桂西南15年生马尾松人工林近自然经营中宜选择300株·hm~(-2)的保留密度进行采伐。 相似文献
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Black walnut (Juglans nigra) is a prime tree species for agroforestry practices in the United States providing highly prized wood and nuts for human
consumption and wildlife. In 54 black walnut stands in south central United States, the site index (i.e., mean dominant height
[DH], at age 25 years) ranged between 5.2 and 21.4 m, and was independent of stand density. There were no differences in height
and stem diameter (DBH) growth rates between stands with improved varieties and native stock. Most stands were in a “free
growth” stage because of either early age or wide spacing. Mean annual increments in DBH and height were positively related
both for improved varieties and native stock. Understory competition had a substantial detrimental effect on DH. In a 26 year-old
stand, trees growing within Kentucky blue grass (Poa pratensis) had a site index 5 m greater than trees growing within tall fescue (Festuca arundinacea). Predicted nut yields in 2002 varied between 0 and 1370 kg of hulled nuts per ha. Improved varieties had, in general, higher
nut yields than predicted from a nut yield-DBH equation developed for individual trees. Nut yields were highly variable both
within and among stands, and were related to DBH in native stock but not in improved varieties. 相似文献
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M. Elena Alañón M. Soledad Pérez-CoelloIgnacio J. Díaz-Maroto Pedro J. Martín-AlvarezPablo Vila-Lameiro M. Consuelo Díaz-Maroto 《Forest Ecology and Management》2011,262(2):124-130
For the current study, the volatile and semi-volatile composition of several samples of Quercus pyrenaica wood from NW Spain were analyzed and compared. The research was performed on a wide sample set of more than 100 samples (test tubes) obtained from different stands of this species. The relationship between some silvicultural and site parameters and volatile composition was studied. Altitude seemed to be the most influential parameter on the volatile composition. However, other factors such as distance from tree center, average annual precipitation, and number of trees per hectare whose effects on the volatile compounds were not significant. The influence of soil texture was not a determining factor while geographical location seemed to have a more specific impact on the extractive volatile content. The content of all extractable compounds studied allowed a good separation of oak samples of the same species according to their geographical origin. 相似文献
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Elena Marcos Leonor Calvo José Antonio Marcos Ángela Taboada Reyes Tárrega 《European Journal of Forest Research》2010,129(1):25-30
We aimed to study tree effects on the chemical properties of forest soils. We compared soil features of three types of forest ecosystems, each with four stands (replicates): beech forests (Fagus sylvatica), oak forests (dominated by Quercus pyrenaica) and pine plantations (Pinus sylvestris). Five samples from the top 10 cm of soil were taken per stand, from which pH, organic matter content (O.M.), total nitrogen (N) and available calcium (Ca2+), magnesium (Mg2+), potassium (K+) and sodium (Na+) were determined. Litter layer depth was measured at each soil sampling point. We also measured tree density and crown diameters at each stand. Our results indicated that soil samples from the four pine plantation stands were more similar while oak and beech stands were characterised by great variability in terms of soil properties and leaf litter depth. Although the identity of the dominant tree species significantly influenced several topsoil chemical properties (increase in pH and available cations in oak forests and higher organic matter and total nitrogen in beech and pine ecosystems), there were other important factors affecting soil features that may be taken under consideration. Differences between soil properties of the three types of forest ecosystems were mainly related to the characteristics of the litter layer and less related to the tree layer structure. Finally, the establishment of pine plantations in naturally deciduous tree areas made the topsoil features more homogeneous. 相似文献
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《Forest Ecology and Management》2005,209(3):225-235
This study examined the impact of pre-commercial thinning (PCT) on tree growth, product recovery, stand value and financial return in jack pine stands in Northwestern Ontario. Ten sites composed of both control and PCT stands representing various stand densities (2000–6000 trees/ha) and stand ages (26–36 years old) were selected for this study. Three thousand and eighty-two trees were measured for DBH and total height, and were reconstructed in 3-D using a taper equation for jack pine. The reconstructed virtual trees were then “sawn” using the software package Optitek to obtain optimal lumber value recovery, which was then used to determine total product value per tree and financial return. The quadratic mean DBHs of trees from the PCT stands were significantly larger than those from the control stands for all 10 sites. Six of ten PCT stands had significantly taller trees than did the controls of the same sites. With increasing stand density, tree DBH decreased in the control stands while no consistent pattern could be recognized for the DBH of the PCT stands. The increment in average DBH due to PCT increased with increasing thinning intensity. PCT reduced total tree volume per hectare, benefited merchantable stem volume per hectare, and improved the total lumber volume and value recovery per hectare. On average, the PCT stands produced approximately $2760 and $1770/ha (or 19.6 and 16.1%) more product value per hectare for the dimension mill and stud mill, respectively. PCT also significantly reduced logging and lumber conversion costs. Higher total product values and lower total costs resulted in higher benefit/cost (B/C) ratios in the PCT stands than did in the control stands. The increased financial return due to PCT is associated with the magnitude of difference in quadratic mean DBH resulting from PCT. The B/C ratio difference between control and PCT stands increased with increasing thinning intensity. Overall, this study indicates that PCT appears to be an economically viable silvicultural investment for jack pine stands in Northwestern Ontario. 相似文献
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Wenhua Xiang Shaohui Liu Xiangdong Lei Shane C. Frank Dalun Tian Guangjun Wang Xiangwen Deng 《Journal of Forest Research》2013,18(1):111-120
Secondary evergreen broadleaved forests are precious remnants for biodiversity conservation and templates for sustainable management of natural forests in subtropical China. Floristic composition, size structure, and spatial pattern of dominant tree species have been investigated for a subtropical secondary evergreen broadleaved forest in the Huitong Yingzuijie National Forest Reserve, Hunan, China. The location of all trees greater than 4 cm in diameter at breast height (DBH) were mapped within a 0.96-ha plot in which species, DBH, and total tree height were recorded. Ripley’s K(t) function was used to analyze spatial patterns and associations. The secondary forest consisted of 74 tree species and 1,596 stems per hectare. A reverse-J shaped DBH classes distribution was observed for all stems and trees of later seral species whereas trees of earlier successional species were distributed irregularly. Significant aggregated spatial patterns were observed for all trees within the forest and for conspecific trees of each dominant species. This result, and a repulsive spatial pattern for interspecific trees of Choerospondias axillaries and Cyclobalanopsis glauca against other dominant tree species, support segregation hypothesis. Contributions of seed dispersal, topographic heterogeneity, and competition to spatial patterns of conspecific trees vary depending on tree species. Attractive spatial pattern among interspecific trees of Liquidambar fortunei, Liquidambar formosana, and Pinus massoniana reflects stochastic colonization of pioneer tree species and a facilitation relationship. Although deciduous species are long-lived and persist over long successional processes, they will eventually be replaced by late seral evergreen species within the secondary forest if no disturbance events occur. 相似文献
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立地条件对落叶松人工林生长的影响 总被引:1,自引:1,他引:0
通过对日本落叶松(Larix kaempferi)人工林在不同立地条件下的生长调查,结果表明,日本落叶松在生长过程中,受土层厚度、林地位置、立地指数等多方面因素的制约:厚层土胸径年生长量比中层土和薄层土高9.2%~26.7%,树高年生长量高21.8%~44%;生长在N坡,坡度较缓、山地下腹为优;在不同的立地指数级中,生长差异明显,18以上指数级比14~18指数级胸径生长量高25.4%,比14以下指数级胸径生长量高33.8%,树高生长量,18以上指数级比14~18指数级高26.7%,比14以下指数级高36.3%。培育日本落叶松人工林,选择优质立地条件不但可提高林木的生长速度,又能促使林木优质高产。 相似文献