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1.
刚果12号桉林地土壤肥力监测初报 总被引：4，自引：0，他引：4
本次土壤肥力监测试验，以处理九（Ｎ３Ｐ３Ｋ３）效果最佳，处理八（Ｎ３Ｐ２Ｋ２）次之，对照处理（Ｎ１Ｐ１Ｋ１）最差。为了提高林木生长量和质量，造林前要下足基肥，造林后要以Ｎ、Ｐ、Ｋ科学配比适时进行追肥，同时要适时适量加施生理碱性肥料，使土壤养分发挥应有的效能。 相似文献
2.
１９９０～１９９３年连续４ａ，对马尾松球果和种子的生长发育与养分动态，进行了比较系统的分析研究。结果表明：（１）马尾松球果系２年成熟，授粉（４月上旬）后当年为幼球果形成期；第２年受精前的６月至以后的９月中旬为球果迅速生长期，９月下旬至１０月为球果成熟期。（２）在２年生球果生长期间，球果干物质不断增加，而水分含量逐渐减少，１０月底干物质与水分的含量达到平衡点。（３）球果养分的含量，ｌ年生球果幼期Ｎ＞Ｋ＞Ｐ，三者变化趋势近乎一致，２年生球果含Ｎ量明显下降。种子内的Ｎ、Ｋ含量在７月中两者相当，此后Ｎ含量上升直至成熟期，到１０中Ｋ与Ｐ的含量相近。（４）胚胎发育进程中，球果和种子的体积与养分含量在原胚和幼胚阶段（７月至９月中旬）的变化最大，以后渐趋平缓。 相似文献
3.
杉木北带幼林施肥效应研究 总被引：3，自引：0，他引：3
４年试验结果表明，在杉木北带河南鸡公山花岗岩母岩发育的黄棕壤上，人工杉木幼林施肥后２年效应十分明显，第３年效应下降；施ＮＰ２Ｋ１混合肥（１００Ｎ＋１００Ｐ２Ｏ５＋１００ｋ２Ｏｋｇ／ｈｍ２）效应最好；在阳坡试区，施肥后３年，树高生长增加６８％，地径生长增加７８％；Ｐ２Ｋ１（１００Ｐ２Ｏ５＋１００Ｋ２Ｏｋｇ／ｈｍ２），Ｐ１Ｋ１（５０Ｐ２Ｏ５＋１００Ｋ２ＯＫ２Ｏｋｇ／ｈｍ２）和ＮＰ２（１００Ｎ＋１００Ｐ２Ｏ５ｋｇ／ｈｍ２）处理效应也较显著；单施Ｎ、Ｐ肥，前２年也有效应，但肥效低于ＮＰＫ混合肥，单施Ｋ肥效应不好。林分本底值对幼林生长影响极显著，干扰肥效 相似文献
4.
美国栎属种源引种,变异研究：幼树年高生长节律和物候期的变异 总被引：4，自引：2，他引：2
对定植在江苏省林业科学研究院苗圃（南京）内的美国栎属３个树种,１９个种源、家系（包括柳叶栎９个种源、家系,北方红栎６个家系,红栎４个种源）的２年生幼树进行了年高生长节律和物候期（包括展叶期、叶变色期和落叶期）的定期观测（分别每３～１５ｄ观测１次）。结果表明：（１）３个树种在南京年高生长节律差异显著。柳叶栎在生长期内抽梢次数较多,在５次以上,基本呈连续生长趋势。生长节律呈快（５月）－慢（６月）－最快 相似文献
5.
采用生长快、材质优、抗性强的山杨优良品系为材料，通过组织培养获得细胞愈伤组织，再以锈孢子菌为活体病原菌进行接种，经多代反复筛选，获得出Ｐ２１５－３、Ｐ３０６－９、Ｐ３１８－１三个抗锈病细胞系，并诱导其形成植株。经３个世代（细胞团）、３个地区连续３年抗性鉴定，确认以上３个山杨抗锈病优良新种质表现出稳定的抗性，发病指数平均为２．９％，其中Ｐ３１８－１为２．５％，而对照Ｐ２０３发病指数平均为１６．６％。 相似文献
6.
在对毛白杨连续５年施肥的基础上，进行了当年生枝条不同叶位之叶片鲜重、电导率、ｐＨ对施肥反应的试验，结果表明，叶位不同，诸指标对施肥的反应不同，叶鲜重、叶电导率依次均为：上位＞下位＞中位，ｐＨ排序为：上位＜下位＜中位；对肥料反应最敏感的叶片部位为上位叶片；相同的叶位（上位叶）、不同的施肥处理，按其作用大小排序叶鲜重、叶电导率均为：Ｎ肥处理：Ｎ３＞Ｎ２＞Ｎ１；Ｐ肥处理：Ｐ１＞Ｐ２；Ｎ、Ｐ配合：Ｎ２．Ｐ１＞Ｎ１．Ｐ１；ｐＨ：Ｎ３＜Ｎ２＜Ｎ１Ｐ１＜Ｐ２Ｎ２．Ｐ１＜Ｎ１．Ｐ１；综合排序，Ｎ２．Ｐ１施肥处理效果最突出 相似文献
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8.
在广东省开平市镇海林场进行了尾叶桉无性系幼林施肥试验,４．５ａ试验结果表明,８个不同施肥处理（肥料配方）间的生长差异极显著,尤以Ｎ７５Ｐ２００Ｋ５０处理最好,其平均树高为１５．２３ｍ,平均胸径为１１．０７ｃｍ,每公顷材积为１０７．５ｍ３。８个施肥处理均与不施肥处理有极显著的差异。最好施肥处理的平均树高、平均胸径和每公顷材积分别是不施肥的１．３、１．６５和３．１倍。以最佳施肥处理Ｎ７５Ｐ２００Ｋ５０的经济效益最好,投入与产出比为１∶２．２,与施肥量最高的处理相比,投入少,产出大,内部收益率为２５．９６％。 相似文献
9.
土壤本底与毛白杨幼林施肥效应间关系的研究 总被引：2，自引：0，他引：2
通过对定州市毛白杨幼林施肥试区土壤本底分析及４年的施肥效应调查,结果表明：该区土壤肥力低下,富钾、少磷、氮素尤缺;施肥效应与土壤本底密切相关;单施氮肥,林木材积随着施氮量的增加而增加,即Ｎ１＜Ｎ２＜Ｎ３,材积分别为对照的１２６．５％、１４９．０％、１７１．４％;单施磷肥,材积随着施磷量的增加而增加,即Ｐ１＜Ｐ２,材积分别是对照的１４２．９％和１５７．１％;单施钾肥无效;氮磷配合差异显著,Ｎ１·Ｐ１和Ｎ２·Ｐ１处理,毛白杨材积分别为对照的１４６．９％和１４９．０％;氮钾配合等同单施氮肥效果。 相似文献
10.
尾叶桉 湿地松1～6年生施肥效应研究 总被引：3，自引：2，他引：3
尾叶桉、湿地松１～６年生幼林施肥结果表明：１．尾叶桉在缺Ｐ的立地上,施Ｐ肥的效应极其显著。施Ｐ各处理在１～６年生时均显著或极显著地大于对照,其中以施ＮＰＫ全肥最好,６年生的树高、胸径和材积与对照比较,分别增长３５％,６９％,２４３％。而施ＮＫ肥的生长与对照差别不大。湿地松１～２年生的幼林施肥效果不大显著,３～６年生时才达显著差异,其中以施ＮＰＫ全肥的效果最好,６年生的树高、胸径和材积与对照比较仍分别增长１３％,１８％,５２％。２．尾叶桉、湿地松施Ｐ肥的各水平均达显著或极显著差异,施Ｎ、Ｋ肥的只在个别年度有差异。３．偏相关和复相关分析结果表明,尾叶桉施肥肥效主次顺序是Ｐ、Ｎ、Ｋ,湿地松是Ｐ、Ｋ、Ｎ。两树种均在５,６年生时,Ｎ、Ｐ、Ｋ的肥效最高。４．最优施肥配方：尾叶桉１～３年生以施Ｎ３Ｐ３为好,５～６年生以施Ｎ３Ｐ３Ｋ２为佳。湿地松１～２年生不用施肥,或薄施Ｎ肥;３～６年生以施Ｎ１Ｐ３Ｋ１较好。 相似文献
11.
《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
12.
《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
13.
《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
14.
《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
15.
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
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《Scandinavian Journal of Forest Research》2012,27(5):472-479
Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken. 相似文献
18.
Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic
or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts
(stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea
(Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content
as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest
N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized
to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea,
largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for
N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant
components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N
released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures
were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality
components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in
the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols.
Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest
age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its
components are mixed. 相似文献
19.
A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste
disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization,
(2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two
pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea
(Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect
on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage
sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but
affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral
systems.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
《Scandinavian Journal of Forest Research》2012,27(2):166-178
This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes. 相似文献