4种处理对杜鹃红山茶种子萌发的影响

为探索不同处理对杜鹃红山茶种子萌发的影响,以8-9年生杜鹃红山茶植株新鲜种子为材料,探讨GA_3、IAA、6-BA的应用,基质种类,播种深度以及低温沙藏等处理对种子发芽势和发芽率的影响。结果表明,(1)GA_3浓度与处理时间对杜鹃红山茶种子发芽率影响显著,高浓度的GA_3溶液浸种有利于种子萌发,发芽率最高的激素组合为600mg/L GA_3+100mg/L IAA+600mg/L 6-BA+浸种3h;(2)杜鹃红山茶种子萌发对播种环境响应较敏感,播种深度应综合播种基质种类共同考虑,采用混合基质(V椰糠︰V珍珠岩=2︰1),播种深度为1cm,种子萌发效果最佳;(3)低温沙藏能显著提高杜鹃红山茶种子萌发效果,随低温沙藏时间的增加种子的发芽势和发芽率呈逐渐增高的趋势;(4)经低温沙藏的种子继续用GA_3浸种,可进一步提高种子发芽率,种子经低温沙藏60d后采用300mg/L GA_3浸种3h,发芽率最高,为67.78%。     

马挂木种子发芽试验简报

对马挂木鲜种子和砂藏咱子进行变温或恒温、浸种呈不浸种等不同处理的室发芽试验，以及砂藏、干藏和不经贮藏而采用早播等马挂木种子的场圃发芽试验表明：测定调制好的鲜种子发芽率必需进行变温浸种处理，有胚种子的萌发效率达８０％左右，良芽率基本一致，测定砂茂个种子发芽率，不为温或中与否，萌发效率基本相同，为８５％左右，因此可按常规方法测定即可，马挂木种子在播种前腚经２个月砂藏处理，方法简便，效果明显，不仅有胚种     

樟子松播种育苗

1　种子采集及处理9～ 10月在生长 2 0～ 80年以上的健壮母树上采摘球果 ,经水浸、干燥、去翅等处理 ,取得纯种 ,进行层积沙藏 ,也可干藏 ,如干藏种 ,翌年播种前最好对种子进行消毒和温水浸种催芽 ,方法是 :在 4月上旬 ,用0 .3%～ 0 .5 %的高锰酸钾水溶液浸种 2ｈ后 ,用清水冲洗 ,用 5 0℃温水浸种 2ｄ ,每天换清水两次 ,捞出后 ,置于大盆或开口木箱中 (箱底有小孔 ,箱底铺沙布 ,种子倒入后 ,上面再以沙布覆盖 ) ,每天用 2 0～ 30℃温水冲洗两次 ,3～ 5ｄ后有 5 0 %种子裂口时即可播种。2　整地作床圃地以沙壤土为好 ,西北山地以东南坡向为…     

不同种子处理方式对长柄扁桃成苗率及苗木生长的影响

通过长柄扁桃引种育苗,研究了不同种子处理方式对其成苗率及苗木生长的影响,结果表明:40℃温水浸种→混湿沙冷窖储藏、干种子窄藏→不同温度梯度浸种→不冷冻及干种子窖藏→不同温度梯度浸种→冷冻等3类种子处理方式的长柄扁桃的最高成苗率由高到低依次为72.5%、51.8%和9.0%,各处理间成苗率存在明显差异;不同处理方式种子发育成的苗木平均高生长和平均地径生长存在差异,40℃温水浸种→混湿沙冷窖储藏处理和40℃温水浸种→不冷冻处理,成苗率和幼苗高径生长两项指标均较高。长柄扁桃育苗中种子处理应采用上述2种方法,尤以40℃温水浸种→混湿沙冷窖储藏处理种子效果最佳。     

毛竹育苗及栽培技术

一、毛竹育苗技术(一)播种育苗1.种子处理。一是浸种消毒。将种用0.03%的高锰酸钾温水(50℃左右)浸种24小时;二是种子催芽。将砂子用0.03%的高锰酸钾溶液淋湿,再按3:1的比例与种子混合,堆积在18℃～25℃的屋内催芽。每2天喷1次水,至种胚露白点后筛出拌砂,再用清水洗,可提高发芽率5%～8%。     

8种造林树种不同催芽方法种子发芽率比较

研究了日本落叶松、山杏等8种造林树种在不同催芽处理下种子的发芽率,得出了8种造林树种的最佳催芽方法：1）日本落叶松种子为雪藏法,发芽率达88．2％。2）刺槐种子播种前10天用10倍体积的90℃水处理,发芽率为91．8％。3）黄菠萝种子宜在保持不干的状态下低温处理,发芽率为85．3％。4）水曲柳、刺五加果实采收、种子取出后立即进行高、中、低温沙藏,其发芽率分别为90．0％和92．0％。5）文冠果种子宜播种前进行3个月的低温沙藏,发芽率为95．3％。6）辽东栎种子应采收后立即低温沙藏,发芽率为94．0％。7）山杏种子宜在1月初浸泡并进行低温沙藏,发芽率为91．7％。     

不同理化处理方式对文冠果种子萌发的影响

为了筛选文冠果种子的最佳催芽方式,以文冠果实生种子为研究对象,分别采用物理和化学方法对其进行了处理,物理方法设置了干藏、低温、混沙层积3种贮藏条件和30℃、50℃、80℃3个梯度的浸种温度;化学方法设置了6-苄基胺基嘌呤(6-BA)、萘乙酸(NAA)、ABT 3种植物生长促进剂以及1 d、3 d、5 d 3个梯度的处理时间,进而探究了不同理化处理方式对文冠果种子发芽率和发芽势的影响。结果表明,文冠果种子萌发的最佳物理处理方式为混沙层积贮藏后80℃浸种,最佳植物生长调节剂处理方式为ABT浸泡处理5 d。     

不同处理方法对油松种子萌发的研究

为了筛选油松(Pinus Tabulaeformis Carr.)种子的最佳催芽方式,试验以油松种子为研究对象,分别从物理和化学2方面对其进行了处理,物理层面设置了干藏、低温、混沙层积3种贮藏条件和30、50、80℃3个梯度的浸种温度;化学层面设置了6-苄基胺基嘌呤(6-BA)、萘乙酸(NAA)、ABT6号生根粉3种植物生长促进剂以及1、3、5d3个梯度的处理时间,进而探究了不同理化处理条件对油松种子发芽率和发芽势的影响。结果表明,油松种子萌发的最佳物理处理方式为混沙层积贮藏后80℃浸种,最佳植物生长调节剂处理方式为ABT6号生根粉浸泡处理5d。     

树木种子的休眠的解除

解除树木种子休眠常用的方法,有以下几种。一、浸种:多数树木种子在播种前浸水,可提早萌发,特别是冬播种子延迟到春播更需浸种。池杉种子在播种前浸水2-3日,发芽所需日数由一个半月提早到7天,亩产量提高二倍以上;女贞种子干藏到来年4月播种,当年不能萌发,如浸水一周,几天就发芽,泡桐、楸树种子浸水48小时,可以提早萌发,而且出苗整齐;湿地松种子浸水10天,就能加速发芽。二、温度:采用低温、高温和变温处     

五角枫大苗培育技术

五角枫,主要用于庭院绿化、行道树、观赏树种栽培。一、采种及种子处理10月份翅果成熟变褐色时及时采种,晒3~4天敲打取种,风选去杂后干藏或砂藏,种子含水量为8%～11%。翌年春播前催芽处理,用40～50℃温水浸种2小时,捞出后洗净种子,用2倍的干净粗砂混合,放室内温暖处堆     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

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.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

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.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

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.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

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.     

CAD与建筑设计的关系

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

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.     

Risk Perception Among Non-industrial Private Forest Owners

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.     

Interactions in decomposition and N mineralization between tropical legume residue components

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.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

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.