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1.
武汉地区引种灯台树栽培技术与速生因素研究 总被引：1，自引：0，他引：1
通过20a3次引种珍稀灯台树,证明灯台树在武汉地区引种成功,且生长迅速。当年苗期平均高生长达89cm。大树年平均高生长达1·2m,胸径1·12cm,大大超过桢楠、紫楠、白玉兰等其他珍稀种,很有开发利用价值。 相似文献
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在我国北亚热带安徽滁州琅琊山林场进行美国岩榆和南方岩榆引种育苗试验,旨在验证其对当地土壤和气候条件的适应程度,为进一步引种与推广作准备.结果表明:岩榆、南方岩榆发芽率分别为76%、54%;两种榆树苗木前期生长均较慢,100 d时,岩榆苗木平均高为16.5 cm,南方岩榆13.5 cm.它们的速生期始于7月份,且峰值均出现在8月,到11月下旬生长均逐渐停止,落叶时间均普遍比作对照的白榆迟7-14 d.岩榆1 a生苗木平均高61.5 cm,最高达96 cm;南方岩榆1 a生苗木平均高53.5 cm,最高达94 cm;白榆1a生苗木平均高73 cm,最高达112 cm.南方岩榆约0.3%苗木有尺蠖危害,而岩榆、白榆及南方岩榆混生苗没有受此危害. 相似文献
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2002～2004年在南京、江都、无锡等地引种大叶樟试验表明,苗期高生长呈现单峰形,5～6月开始生长,7～9月速生,7月呈现峰值,10月生长下降后趋于停滞.生长与气温、湿度和光照关系密切,显著或极显著正相关.苗期1～2 a与当地香樟一样在-7℃极端低温下有较重冻害,但冻害轻于香樟;3 a时苗木冻害显著减轻,5 a时未见明显冻害.1～2 a生苗树高年均净生长量达0.83～0.99 m,3 a达0.95 m,5 a达0.85～0.98 m,显示出速生潜力.5 a生苗平均树高达4.26～4.88 m,胸径5.8～6.5 cm,冠幅2.0～2.5 m,已达城市行道绿化和园林绿化出圃标准.苗木耐湿性较强,在地面淹水20 h,深10 cm的情况下,1 a移植苗未见受害.引种苗期1～3 a和幼龄初期5 a未见明显病虫害.由此认为,大叶樟是樟科生长适应性较强的常绿观赏阔叶树,可在南京及苏南地区城市森林建设、园林绿化中扩大应用. 相似文献
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南京引种邓恩桉、冈尼桉苗期试验初报 总被引：14，自引：2，他引：12
在我国北亚热带江苏南京南郊进行邓恩桉和冈尼桉两个耐寒桉树的引种试验 ,苗期研究结果表明 ,夏雨型种邓恩桉播种后出苗较快 ,3月中旬播种 ,一般 10d开始出苗 ,2 0d时苗木基本出齐 ;冬雨型种冈尼桉播种后出苗较迟 ,一般 2 0d才开始出苗 ,4 0d时苗木基本出齐。两种桉树苗木前期生长较慢 ,10 0d时 ,邓恩桉平均苗高 16 4cm ,冈尼桉仅 5 1cm。邓恩桉于 7月开始速生 ,8月呈现峰值 ,至 11月下旬逐渐停止生长。 1a生苗平均高 1 6 3cm ,最高可达 2 5m。冈尼桉不适应南京地区夏季高温 ,在遮阳网覆盖遮荫降温条件下 ,7月陆续死亡。邓恩桉对低温有一定的适应性 ,在冬季 - 7℃自然低温下 ,仅叶片边缘及少量嫩芽出现轻度寒害 ,显示出引种潜力 相似文献
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福建柏和杉木人工林细根生产力、分布及周转的比较 总被引：20，自引：3，他引：20
对福建三明福建柏和杉木人工林细根生产力、分布及周转进行了为期 3年的研究 ,结果表明 ,福建柏年均细根生物量达 389 7g·m- 2 ,是杉木林 (2 77 2g·m- 2 )的 1 4 1倍 ;活细根年均生物量达 2 16 3g·m- 2 ,是杉木林(14 8 4g·m- 2 )的 1 4 6倍 ;<0 5mm细根生物量 (2 4 2 2g·m- 2 )则是杉木林 (12 4 7g·m- 2 )的 1 94倍 ,其占总细根生物量比例 (6 1 2 % )比杉木林 (4 5 0 % )的高出 16 2 %。福建柏和杉木细根垂直分布在 0～ 10cm土层差异最大 ,该层福建柏总细根密度 (14 4 2g·m- 2 )是杉木 (70 2g·m- 2 )的 2 1倍。福建柏林活细根生物量 1年只出现 1次峰值 (3月 ) ,而杉木林活细根则出现 2次 (3月和 9月 )。福建柏不同径级细根第 1年分散速率及分解系数均低于杉木的。福建柏林细根年净生产量 (32 0 2g·m- 2 a- 1 )和细根年死亡量 (32 6 5g·m- 2 a- 1 ) ,分别是杉木林 (2 5 1 3和 2 4 9 2g·m- 2 a- 1 )的 1 2 7倍和 1 31倍。福建柏细根年均周转速率为 1 4 8a- 1 ,低于杉木林的 (1 6 9a- 1 )。福建柏和杉木细根生物量分别仅占其乔木层生物量的 1 70 %和 1 18% ,但细根净生产力却分别占其乔木层总净生产力的 19 84 %和19 2 1% ,细根年死亡量分别占地上部分凋落物量的 4 8 74 %和 5 1 0 0 相似文献
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在宁夏选择不同立地条件的造林试验区,进行了梭梭(H.ammodendron)人工造林试验研究,通过2年的调查研究,在地下水位较高,苗期管理规范的试验区,当年平均株高达47.98cm,平均地径0.53cm,第二年平均株高达93.21cm,平均地径0.91cm。梭梭当年造林根系生长快,第二年地上部分生长迅速,株高和地径增长率为94.3%和71.6%。沙质土壤平均成活率达79.25%,保存率达66.25%,说明我区部分地区立地条件和生态环境适宜梭梭生长,可以进行人工造林。 相似文献
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红松生长发育规律研究 总被引：4，自引：0，他引：4
红松在1a中高生长主要分为三个阶段，开始生长期(5月初-5月20日)，生长速生期(5月20日-6月5日)，生长末期(6月5日-6月20日)，部分红松二次高生长出现在8月5日-9月10日。各期高生长与各期积温关系密切。15a红松高生长分为缓苗期(3a生苗造林后4a内)、加快期(造林后5—8a内)、速生期(造林后9—12a)。速生期内，树高连年生长量平均达40cm，最大者达90cm。树高近5a定期生长量及15a总平均生长量均是北亚区大于南亚区，南亚区大于中亚区，但是，近3a、2a、当年生长量都是南亚区大于北亚区、北亚区大于中亚区。 相似文献
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以3种造林方式(18 a杉木林下套种闽楠、闽楠纯林、闽楠与杉木混交林)营造的闽楠试验林为对象,分析造林2 a后幼林生长情况,利用Win-RHIZO根系分析系统比较不同造林方式闽楠根系性状的差异。结果表明:杉木林下套种闽楠的平均地径、最大冠幅、苗高、枝下高、单株总根长、总表面积、根系总体积、根深和平均根幅均最大,依次为11.60 mm、61.33 cm、115.56 cm、32.42 cm、1269.13 cm、376.75 cm^2、9.32 cm^3、47.50 cm、48.42 cm;3种造林方式下闽楠单株根总长度均在根系直径0 mm4.5 mm、0.5 mm-2的林下套种方式最适合闽楠生长。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
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Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and
also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the
amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter
bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K
was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed
significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week−1 for leaves and from 0.0225 to 0.0633 week−1 for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed
during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly
between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species
provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient
enrichment capacity and slower decomposition rates which would minimize leaching losses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):118-130
The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
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Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional
data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral
contents and B1 and B2 vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising
germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B1 88 mg 100 g−1, B2 187 mg 100 g−1, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal
diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties
to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations. 相似文献
19.
《Wood material science & engineering》2013,8(2):76-84
Abstract Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists. 相似文献
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本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献