青檀播种育苗技术研究

笔者介绍了太宽河保护区青檀的资源现状,从种子采集、种子处理、整地、播种方式与播种时间几方面阐述了青檀的播种育苗技术。同时分析了干藏秋播、干藏春播、砂藏春播3种不同处理对青檀种子出苗及幼苗生长情况的影响。结果表明,不同处理对青檀种子出苗率、苗木保存率、苗木生长量均有显著影响;以干藏秋播和砂藏春播苗木生长最好,以秋播处理用工最少。     

不同时期播种对山桃稠李苗木生长的影响

山桃稠李种子经变温层积处理,采用不同播种时期(春播和秋播)对苗木出苗及生长量的影响,旨在为该树种的实生苗培育提供实践经验。结果表明,春播、秋播均可出苗,秋播苗生长量高于春播苗。     

高寒山区仁用杏育苗技术研究

高寒山区仁用杏育苗的关键是砧木苗的培育。如果播种当年秋季砧木苗粗度能够达到嫁接标准，可和气候条件较好的地区一样，两年培育良种仁用杏成品苗。采用家杏种子播种育苗，砧木苗高、径生长比山杏快，当年秋季基本上可以达到芽接标准；秋季播种优于春季播种，秋播苗木出土早、出土时间短，苗木整齐，且生长期延长，当年秋季９４％的砧木苗可达到芽接标准；苗木摘心对促进砧木苗粗生长有很大作用，以速生期摘心两次效果最好；苗木速生期进行叶面喷肥效果显著，最佳选择为０．５％尿素＋０．５％磷酸二氢钾。     

杉木秋播育苗好

我场位于开化县西部,植物生长期约240天。培育杉苗多在二月下旬至三月上旬播种,“清明”左右杉苗出土揭草,杉苗地上部份生长期约210天。为了培育粗壮高大的杉苗进行造林,我们于一九七三年开始进行杉木秋播育苗试验,并将试验结果用于大田生产,通过四年来的实践证明杉木秋播育苗比春播育苗好。     

黑河中游典型退化沙地文冠果引种栽培试验研究

随着我国生物质能源战略的确立,在内陆河流域对文冠果栽培研究目前面临着巨大历史机遇,也给黑河流域文冠果栽培提供了契机。通过引种栽培文冠果试验研究表明:在黑河流域中游沙地文冠果育苗,种子处理采用冰冻和高温快速处理、播种采用覆膜点播及秋播育苗效果好;文冠果栽植前采用一定浓度的ABT3号生根粉处理苗木根基部,栽植成活率较未处理的造林成活率提高25.8%;文冠果在黑河流域典型沙地造林,以当地培育的苗木造林为主,应尽量选在土层较厚、土壤肥力较高的区域造林。     

用隔年苦楝种子培育壮苗

我们在苦楝育苗过程中了解到由于苦楝果核坚硬,播种后分化时间长,种子发芽出土迟,苗木生长期短,影响高、粗生长。为了提高苦楝苗的质量,我们于一九六九年进行了隔年苦楝子(果核经一年时间沙藏)育苗试验。结果隔年种子比当年种子提早出土近一个月,种子发芽整齐,苗木生长均匀。     

鄂尔多斯地区文冠果大田育苗的影响因素分析

通过文冠果大田育苗的正交试验,分析鄂尔多斯地区对文冠果育苗的几种影响因素。试验结果表明:种子的播种期、覆土厚度、土壤的p H值对文冠果出苗影响较大,在覆膜的情况下,5月中旬播种、覆土3 cm比较合适;贫瘠的土壤上育苗,需要施肥来补充苗木生长所需的养分;对于文冠果成苗来说,有一定的土层厚度才能较好地生长。     

不同防寒措施对引种的加拿大糖槭抗寒生理指标的影响

对引种的2年生加拿大糖槭苗分别进行稻草防护、窖藏处理,并以野外露地越冬生长的苗木为对照,研究不同处理的加拿大糖槭苗在生理及形态等方面对低温的反应,结果表明:在自然条件下的苗木形态指标不如稻草防护的苗木,窖藏的加拿大糖槭的苗木质量又优于稻草防护的加拿大糖槭,因此,对引种幼苗,最好保护方法是窖藏法。     

播种时期对蒙古栎不同类型苗木出苗和生长的影响

以蒙古栎种子为材料,研究播种时期对蒙古栎不同类型苗木出苗和生长的影响,结果表明:蒙古栎在秋季不同时间播种的出苗率均在60%以上,但以早期(9月下旬)播种的出苗率最高(大于80%),早期播种的苗木在苗高、地径、侧根数、根体积和根生物量等指标上都明显要高于其它播种时期,蒙古栎在秋播裸根育苗时应适时早播;秋季播种的容器苗在所有观测的形态指标上均好于春季播种的容器苗,秋季容器育苗质量更高。     

枫香人工育苗技术研究

采用随机区组设计了枫香不同年龄母树种子品质、不同播种时间(春播、冬播)和不同播种方式(条播、撒播)试验,进行枫香不同育苗方式对比研究。结果表明:不同年龄枫香母树种子产量和种子品质存在显著差异,20年生枫香母树种子千粒重、出籽率及发芽率分别均高于40年生枫香母树种子,因此枫香育苗宜选择20~30年生健壮无病虫害的母树采种。不同播种时间育苗的苗木生长和苗木质量无明显差异,春播苗木生长及苗木质量略优于冬播苗木。枫香条播与撒播育苗苗木生长和苗木质量无明显差异,但条播节省种子。因此枫香育苗宜采用条播,1年生幼苗发育可分为出苗期、幼苗期、速生期、苗木硬化期4个时期。     

Field performance of Scots pine (Pinus sylvestris L.) seedlings planted in disc trenched or mounded sites over an extended planting season

Economic pressures have driven an ever-widening period during which foresters use machines to plant Scots pine (Pinus sylvestris L.) seedlings. In Fennoscandia, this period has recently stretched to the entire growing season. To evaluate the performance of seedlings planted during this extended period, three experiments were carried out in Central and Northern Finland over 2 years. One-year-old and current-year seedlings were planted in mounds or disc-trenched furrows when soil temperatures were >0°C. When 1-year-old seedlings grown for spring planting and overwintered outdoors were planted after mid-June, more needles browned and growth was reduced, possibly because seedlings were oversized with respect to planting density and the volume of growth media. When current-year seedlings sown in spring were planted from July to November, those planted in late September and October grew less in later years than those planted earlier, but survival was unaffected. No large differences in field performance were found with respect to whether seedlings were planted in mounds or disc-trenched furrows. In conclusion, Scots pine seedlings can be machine planted in mounds or furrows during May and early June (later in the North) and then continued from early August until late September, provided climatic conditions in late spring and early autumn are typical and similar to those experienced in Central Finland.     

Autumn Fertilization in the Nursery Affects Growth of Picea abies Container Seedlings After Transplanting

Second-year Norway spruce seedlings [Picea abies (L.) Karst.] grown in containers were divided into three fertilization levels in August [5, 15 and 25 mg nitrogen (N) seedling^?1]. The resulting foliar concentrations of N were 11.0, 13.1 and 15.8 g kg^?1, respectively. Seedling height (mean 26.0 cm) did not differ among treatments. The next spring, the seedlings were tested in two experiments. (1) The seedlings were transplanted into pots containing sandy soil in the greenhouse, where they were fertilized with either pure water or nutrient solution (22 mg N l^?1). (2) The outplanting performance of the autumn-fertilized seedlings was tested on a sandy field. In the greenhouse experiment, the autumn fertilization level affected height growth and root egress of the seedlings significantly, but less than fertilization with a nutrient solution after planting. In the field experiment, during the first season after transplanting shoot growth of the seedlings increased with the level of autumn fertilization. After the second and third seasons, the seedling stem volume was highest with the highest level of autumn fertilization. These results suggest that, by improving the preplanting nutrient status of seedlings, the growth of shoot, stem diameter and root biomass can be enhanced after planting, especially on nutrient-poor soils. However, heavier autumn fertilization than that used here may yield a greater and more persistent increment in growth.     

Seasonal photosynthetic responses to light and temperature in white spruce (Picea glauca) seedlings planted under an aspen (Populus tremuloides) canopy and in the open

Photosynthetic light and temperature response curves were measured seasonally in seedlings of white spruce (Picea glauca (Moench.) Voss) grown for two years in the understory of aspen (Populus tremuloides Michx.) or in the open in central Alberta. Light-saturated rate of net photosynthesis, the optimum temperature for net photosynthesis, transpiration rate, photochemical efficiency, and stomatal and mesophyll conductances increased from spring to summer and declined thereafter, whereas dark respiration rate and compensation and saturation points were highest in spring. Depression of photosynthetic parameters was greater in open-grown seedlings than in understory seedlings during the periods in spring and autumn when night frosts were common. Net photosynthetic rates were similar in understory and open-grown seedlings in summer, but they were significantly lower in open-grown seedlings in spring and autumn. Significantly lower transpiration rates and stomatal conductances in open-grown seedlings than in understory seedlings were also observed at 15 and 25 degrees C in the autumn. Shoot and needle growth were less in open-grown seedlings than in understory seedlings. In summer, when irradiances were low in the aspen understory, understory white spruce seedlings maintained a positive carbon balance by decreasing their compensation and saturation points and increasing their photochemical efficiency compared to spring and autumn.     

Early season short-day treatment did not affect the field performance of Pinus sylvestris container seedlings in summer planting

Abstract

When Scots pine (Pinus sylvestris L.) seedlings are short-day (SD) treated in May or early June, height growth ceases but seedlings reflush within a few weeks and grow secondary needles (later referred to as early SD treatment). These “2-year-old-like” seedlings have been thought to be more stress tolerant than traditional 1-year-old pine seedlings, and thus suitable for summer and autumn plantings. To test this, seedlings sown in April were early SD treated over a 3-week period from the beginning of June and the seedlings were planted at 10-day intervals from the beginning of July until the end of September, and also during the following spring. Neither survival nor height growth of early SD-treated seedlings differed from untreated (1-year-old) seedlings. Moreover, for both early SD-treated seedlings and 1-year-old seedlings, those planted in summer grew and survived better after planting but had more multiple leaders than seedlings planted in autumn or spring.     

Effects of nursery shading on seedling quality and post-planting performance in two Mediterranean species with contrasting shade tolerance

In Mediterranean climates, seedlings are frequently shaded in the nursery to avoid heat damage and save water. However, the impact of this shading on the seedling quality and transplanting performance of Mediterranean species is not well known. We studied the effect of nursery shading on pre-planting features and post-planting performance of two Mediterranean tree species: the shade-intolerant pioneer Pinus halepensis and the shade-tolerant late-successional Quercus ilex. We grew one-year-old seedlings of both species under 100, 40 and 5% full sunlight. Shade had a low impact on the morphology and physiology of Q. ilex seedlings. In pines, only the deep shade treatment produced low quality seedlings with poor root development. In both species, transference to high light at planting in autumn did not impose any additional stress than that caused by frosts, but initial root growth was impaired in the two shaded treatments in pine. Post-planting growth and survival of oak seedlings showed no difference between treatments. Pine seedlings grown in deep shade showed higher mortality and lower growth after planting than those grown in full sun and intermediate light treatments, while intermediate light only reduced growth. For the nursery culture of Q. ilex seedlings, we advise using low light levels during summer to save water without impairing field performance. In P. halepensis, seedlings should be cultured under full sunlight conditions to maximize post-planting growth, but they can be cultured under intermediate light without impairing survival.     

Root and shoot allometry of bareroot and container Douglas-fir seedlings

Detailed root and shoot development of bareroot and container Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedling stocktypes were compared during the first growing season after outplanting. The study was installed in raised beds with ideal environmental conditions and at a field reforestation site. Survival at both sites was 98% and did not differ between stocktypes. Seedlings were excavated in spring (5, 8, 12, and 16 weeks after planting) and in fall (35, 40, and 45 weeks after planting). In spring, container seedlings had more numbers of new roots and greater new root and shoot biomass than bareroot seedlings at both sites. In fall, bareroot seedlings consistently averaged more new root growth (though nonsignificant) than container seedlings suggesting that stocktype differences may not continue long-term. Container seedlings had significantly greater water percent than bareroot seedlings at the field site (all sample dates) and the raised bed site (weeks 5, 8, and 40 only). Regardless of environmental conditions or season, seedlings at both sites maintained water percent between 60 and 70% of fresh weight. Seedlings grown in the raised beds had much greater growth than those grown in the field. However, relative growth patterns for the two stocktypes were very similar on each site. The data generated establish baseline differences between stocktypes for root initiation, growth, and allometry during the first year after planting. Challenges associated with root development research are discussed.     

开心果芽接育苗试验

经过3年(次)连续进行春、夏、秋季芽接开心果的试验,结果表明:夏季接活率比春季高18.0个百分点,比秋季高42.7个百分点;春季接活率比秋季高24.7个百分点,秋季接活率仅为34.0%。夏季芽接后到成活需要8d,春季需要半月,秋季所需更长。夏接可比春季多繁育1/3倍的果苗,比秋接多1.25倍;春接比秋接多2/3倍。以夏接为主、春接次之繁育开心果,可早接多育果苗,扩大栽植开心果面积,加快开心果示范园的建设步伐。     

花椒“压苗”栽植方法及其造林效果

压苗栽植是花椒抗旱造林的一个新的栽植方法.用这种方法造林,幼树根系发达,成活率、保存率高,幼树结果早,产量高。以2a生的1级苗压苗造林效果最好。春、夏、秋三季造林均有较高的保存率,但从幼树生长情况来看,春季优于夏季,夏季优于秋季。     

山地景区绿化栽植大侧柏最佳季节的试验

用相同的造林方法,在山地景区栽植大侧柏,最佳季节为雨季7~8月份,这时期雨水充足,缓苗快,不仅造林成活率高,而且成活后,生长状况也优于春、秋两季,且造林施工方便省工,是栽植大侧柏最佳季节。     

三北防护林新无性系-美青杂种系列引进与苗期选择

１９９８年春从中国林科院的实验点甘肃临夏回族自治州林科所引入北方型美洲黑杨（Ｐ．ｄｅｌｔｏｉｄｅｓ）×青杨（Ｐ．ｃａｔｈａｙａｎａ）杂种无性系　１３７个,扦插在内蒙奈曼旗兴隆沼林场二分场。１９９８年秋选出　１３个无性系,加入我地区新近确定的推广无性系──白城　４１作对照,１９９９年建无性系测试圃,２０００年春平茬,２０００年秋对这　１３个无性系生长量和抗性的调查与评价,以白城　４１为对照,初步选择出　１０个无性系,高生长较对照大　３０％以上的有　４个,２０％以上　５个;径生长大　５０％的　３个,３０％以上　２个,２０％以上　４个;所有无性系的抗锈病情况都好于对照。为丰富三北地区营造杨树农田防护林品种和改善三北地区杨树品种单一的问题有望选出新无性系。