共查询到20条相似文献，搜索用时 78 毫秒
1.
丽水市林场南山林区1983年采用嫁接换种技术改造10亩油茶低产林,改造后第二年始果,第三、四年平均亩产茶油6.66公斤,比未嫁接换种的3.27公斤增长104.7％。据测算,到盛果期理论产量每亩可达29.61公斤,比未嫁接的提高近四倍。这10亩油茶嫁接换种的接穗选自经过当代鉴定的14个优 相似文献
2.
嫁接换种改造油茶低产林试验初报 总被引：2，自引：1，他引：1
浙江省油茶无性系鉴定协作组 《经济林研究》1989,7(2):87-88
造成油茶低产原因是多方面的,其中品种类型混杂、良莠不齐是主要原因之一。据1977年油茶良种普查统计,70％的产量来自30％的植株,而70％的植株,只有30％的产量,可见低产劣株所占比例相当大。为此,我们于1983年在油茶无性系鉴定的基础上,选出14个具有一定遗传增益的优良无性系,在丽水市南山林区进行了嫁接换种试验和无性系区域试验,试图通过嫁接换种,改变油茶低产面貌,提高油茶单产;筛选出适合于丽水地区的油茶优良无性系。 相似文献
3.
结合中央财政对长汀县低产油茶林改造的扶持项目,针对长汀县本地小果油茶低产、低效的问题,调查分析了4种不同低改措施对小果油茶低产林的改造效果.结果表明:小果油茶低产林改造是提升小果油茶产量的必要技术措施,不同的改造技术措施比对照组产量增产约64.45％、53.88％、31.11％ 和17.09％;而且增产效果与低改措施的... 相似文献
4.
5.
油茶低产林综合改造效果分析 总被引：7，自引：0，他引：7
针对广西巴马县油茶生产低产低效的问题,进行以平衡配方施肥为主的油茶低产林综合改造技术试验,研究不同低改技术措施对改造效果的影响.结果表明:进行油茶低产林改造的增产作用显著,4种处理措施比对照分别增产57.69%、50.00%、30.77%和19.23%;而且增产效果因低改技术的实施程度不同而有显著差异,4种低改技术措施组合中,处理C1(密林疏伐+整枝修剪+垦复深挖+合理施肥)的改造效应最显著,增产最明显.说明低产林改造技术的每项措施是相辅相成、相互促进的,只有全面实施综合改造才能获得最佳的改造效果. 相似文献
6.
7.
用福建选育的油茶闽43、闽48、闽603个优良无性系和芽苗砧嫁接新技术繁殖苗木，1988年在福安潭头营造试验林。据1992-1995年测产结果，3个品系比对照（CK）分别增产168．10％、132．68％和93．98％。栽培技术管理试验结果表明：定于修剪、土壤施肥及定干和施肥的综合技术比对照管理分别增产5．24％、57．10％和119.26％。以3个优良品系加综合管理比对照种和对照管理分别增加411．40％、179．87％和282．06％。 相似文献
8.
指出了油茶林的主要价值是茶油,为提高油茶林的经济效益和社会效益,需进一步提高油茶林的产量,因此有必要研究不同抚育措施对油茶人工林生物量及其产量的影响,以提高科学管理程度,提升经济效益。在实验样地中,随机选取生长情况、立地条件相似的油茶林作为实验地,分别设置了3组实验林和对照林,统计油茶植株、地下植被和凋落物数量生物量,并计算产量。通过采用不同抚育措施对油茶人工林影响进行了对比,实验结果表明:实施中耕除草、施肥及复垦的抚育措施,能提高油茶林的生物量,且复垦措施更有助于生物量提高;实施嫁接换冠的抚育措施,不能提高人工林生物量,但果实生物量有所增加;三种抚育均能提高油茶林产量,产量提升效果依次为:嫁接换冠>中耕除草、施肥及复垦>中耕除草、施肥。 相似文献
9.
浙江省油茶无性系鉴定协作组 《浙江林业科技》1989,(6)
丽水是浙江省三个油茶基地重点县之一,与清田樟村相连成片,素有“浙南油库”之称。但目前油茶单产低而不稳,平均亩产茶油3公斤左右,主要原因是品种混杂。为此,我们于1983年,在油茶无性系鉴定的基础上,选出14个具有一定遗传增益的优良无性系,在丽水市林场南山林区进行了嫁接换种试验。经过5年观察和两年连续测产分析,平均亩产茶油6.6公斤,比对照高104.7%。初步看出,用优良无性系嫁接换种改造低产林方法简易,增产幅度大,是改造低产林的有效途径。 相似文献
10.
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
16.
《Scandinavian Journal of Forest Research》2012,27(2):131-138
The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided. 相似文献
17.
18.
《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
19.
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
20.
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