辽宁杨树纸浆林发展可行性及技术对策

论述了杨树纸浆材市场需求及展望，杨树纸浆试验林在辽西地区的生长及产量指标，杨树纸浆林主要品种的制浆造纸性能指标，辽宁省杨树纸浆林栽培适宜区域及主要栽培模式，杨树纸浆林栽培技术要点和病虫害防治。     

不同施肥处理对柳窿桉幼林生长的影响

以林木生长所需的3种N、P、K大量元素作为肥料养分组成,设计5种不同施肥处理（含对照）对柳窿桉（Eucalyptus saligna×E.exserta）无性系进行施肥试验。通过对试验林8、21、30个月生时的林木生长调查数据分析,结果表明,施肥可显著促进柳窿桉林木树高、胸径、单株材积的生长,但不同施肥量处理的树高生长没表现出显著差异,而不同施肥量处理间的胸径、单株材积生长差异明显,即施肥量大的处理的胸径、单株材积生长效果要显著优于施肥量小的处理。     

清流县木材战略储备示范基地现有林不同改培方式效果分析

对清流县木材战略储备示范基地现有林进行不同改培方式的对比分析,结果表明:改培方式采用疏伐+套种+施肥的林木生长效果最好,尤其是疏伐的施肥措施效应明显,不论是对主林木还是对林下套种的林木来说,施肥都能明显促进林木生长,提高林分产量。而林下套种,由于整地挖穴人为措施在一定程度上也促进了主林木的生长,但这种效应比施肥效应小。疏伐+套种+施肥的改培方式符合持续经营方向,可作为木材战略储备现有林的主要改培方式进一步推广。     

杨树人工林地力退化及维护与提高土壤肥力技术的研究

在山东，辽宁，河南，河北，北京等五个杨树（ＰｏｐｕｌｕｓＬ．）栽培地区，抽样调查４８块样地，并进行土壤养分化学分析，研究了杨树同代纯林，一代林、二代林生长对林地土壤肥力的影响以及杨树与刺槐（ＲｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａＬ．）、沙棘（ＨｉｐｐｏｐｈａｅｒｈａｍｎｏｉｄｅｓＬ．）、紫穗槐（ＡｍｏｒｐｈａｆｒｕｔｉｃｏｓａＬ．）、混交对土壤营养元素含量，土壤微生物数量，土壤酶活性等方面的影响。研究表明，在相同立地条件下，杨树同代林，随林木生长，土壤养分含量有下降趋势；连栽二代纯林比一代纯林，土壤养分含量及林木生长量有明显下降趋势；杨树与刺槐、紫穗槐、沙棘混交，能够提高土壤肥力，促进林木生长，是维护与提高土壤肥力，防治杨树人工林地力退化的有效生物措施。     

湿地松施肥效果试验阶段初报

以湿地松容器苗当年造林地进行施肥试验,结果表明:湿地松施肥当年主要促进地径生长,第2—4年地径、树高增长作用明显;施肥以复合肥效果最好;施肥量与林木生长呈正相关;合理施肥量为75g/株.     

半干旱地区杨树造纸速生丰产林培育技术及其应用研究成果通过部级鉴定

为了提高我国杨树生产水平,更好地为生产服务,国家经委、轻工业部特将“杨树造纸速生丰产林培育技术及其应用研究”列为国家科技攻关项目。吉林造纸厂于1986年与轻工业部签订了“半干旱地区杨树造纸速生丰产林培育技术及其应用研究”的合同。几年来他们在省林科所的大力协作下,根据合同和研究方案的要求,在王府林场建设了万亩杨树速生丰产林基地,按期完成了各项研究任务。1.改造现有杨树人工林为速生丰产林7025亩。通过对现有北京605杨和小黑杨人工幼林的密度调整、施肥、灌水、抚育管理、病虫害防治等措施,促进了林木生长。年生长达到0.9m~3/亩,超过原合同规定0.7m~3/亩的28%,达到了吉林省丰产林标准。2.新建速生丰产林3004亩。树种以小黑杨为主,采取细致整地、良种壮苗、     

马尾松近熟林施肥技术研究

通过对17a生马尾松近熟林施肥试验4年的生长效应分析表明:在南方红壤地区施适量的P,K肥对马尾松近熟林生长有显著的促进作用,但施用过量却有负作用;施N肥短期内对林木生长不利;施肥效果显著时可掩盖林地本身质量对林木生长的影响。根据对各肥种水平效应值的分析可知,最佳施肥处理为每株混施P2O590g,K2O 90g,其4年蓄积定期生长量比对照高13.4%。施肥措施对促进小径阶木生长有利。在肥效期内施肥措施与马尾松近熟林的生长效应呈显著相关性。     

提高南方丘陵台地林木施肥试验的效率与精度的讨论

从区组内林木生长差异的趋势,分析讨论了提高南方丘陵台地林木施肥试验局部控制效率以及确定合理重复数的一般原则;对现有林施肥和某些区组效率较低的试验,如何更客观地反映试验处理的真实效应或进一步改善试验精度等亦进行了简要的讨论。     

谈谈人工林施肥

林木施肥就是人们有意识地将某种有机或无机的营养物质施人土壤中或喷在植物体上,以改善林木营养状况和促进林木生长,达到速生、高产、优质的目的。尤其是在短伐期林分的经营方面,施肥已成为速生高产林培育不可缺少的技术措施。     

杨树二耕土施肥肥效的研究

通过湖南省围堤湖农场二耕土三年施肥试验表明：在二耕土施肥第一年对杨树树高生长效果不明显，第二、三年施肥效果明显，单施氮肥树高生长增加１５％～２０％，胸径生长增加１８％～２０％；氮磷肥配合使用树高生长增加１５％～１９％的胸径生长增加１７％～２１％。试验证明施肥可以提高土壤肥力，调节树体内营养元素的平衡，促进树高和胸径的生长。本研究成果对促进二耕土杨树速生丰产具有十分重要的实践意义。     

杜仲生长节律与施肥技术简报

杜仲高生长以4－7月份生长最快，6月份达最高峰；径生长以5－7月为旺盛期，其中6、9月各有一次生长高峰；杜仲林地施肥以4－5月为最佳；施肥量为一个区间，且因树龄而异；施肥按坡台地和平地进行沟施和穴施。     

Effect of animal browse protection and fertilizer application on the establishment of planted Nuttall oak seedlings

For establishment to be successful, planted oak must emerge above vegetative competition and browse level. A 3 year study was established in 2000 in a cutover bottomland hardwood forest in west Alabama to examine the influences of seedling browse protection and fertilizer use on growth of Nuttall oak (Quercus nuttallii Palm.) seedlings. The treatments included: control, 1.2 m tall wire tree shelter, and 1.2 m tall plastic tree shelter. Fertilizer (20–10–5) was applied to one-half of all seedlings at planting. Competing vegetation was controlled around all seedlings with mulch mats and herbicide. Fertilization did not affect height growth or successful establishment after 3 years. Four percent of protected seedlings (plastic and wire tree shelters combined) were browsed compared to 95% of control seedlings. After 3 years, plastic tree shelters were the most effective treatment for promoting height growth and successful seedling establishment of Nuttal oak seedlings (193 cm, 92.71% compared to 120 cm, 68.75% and 52 cm, 8.33% for wire tree shelter, and control seedlings, respectively). Animal browse protection is deemed essential for successful seedling establishment in southern bottomland forests where deer density is high (density estimated at 27 km⁻² in vicinity of study area).     

THE MANUFACTURE OF RAYON PULP IN SOUTH AFRICA

The utilization of plantation soils for the growing of pine pulpwood is discussed.

Different tree species make different demands on soil fertility and all tree species grown in S. Africa for commercial purposes also show a fairly wide range ofadaptability to soil fertility and site quality.

Generally plantation soils in this country have reasonable soil depth, good drainage and fair moisture supply but soil fertility levels in higher rainfall areas are often low.

Fertilization in the nursery, at planting time and at an age of 7–10 years of the stand could increase pulpwood yields by about 50 per cent.

Fertilization, cultivation thinning and other silvicultural work which promotes tree growth, all seem to have a similar influence on timber quality. Generally improved rate of growth results in higher timber yields both in total volume and total cellulose yield.

Land available for forestry purposes is limited in this country and it is of great economic and even strategic importance that this land be fully exploited.     

直干桉人工幼林施肥试验初报

对定植3年的直干桉山地人工幼林进行5个处理和1个对照的施肥试验,结果表明:施肥对直干桉山地人工幼林林木的树高、胸径生长有一定的促进作用,但需N、P、K肥一起配合施,此试验最为合理的施肥配方是:150g尿素+200g过磷酸钙+50g硫酸钾,能使树高生长量增加75.4%,胸径生长量增加43.15%,最差的施肥配方是:50g尿素+100g硫酸钾,能使树高生长量增加12.3%,胸径生长量增加8.12%。     

Effects of feathermoss removal, thinning and fertilization on lodgepole pine growth, soil microclimate and stand nitrogen dynamics

The influence of a continuous feathermoss layer (dominated by Pleurozium schreberi) on soil temperature, soil water potential and tree growth was assessed in a 5-year study. The feathermoss layer was manually removed from 900 m² plots in lodgepole pine (Pinus contorta) stands of northwestern Alberta. The interception and retention of nutrients by moss was estimated in N fertilization treatments with and without moss removal. As well, the potential for intraspecific competition to affect nutrient dynamics was assessed through a thinning treatment. Removal of the moss layer increased soil temperatures in summer and increased the period when soil was frost free, but the plots without moss had soil temperature as low as −13 °C in one winter period with little snow cover. Moss removal did not significantly affect N concentrations of the tree foliage but did reduce needle weight. Thinning had little effect on the rate of diameter growth after the first 3 years, but produced a significant increase in growth by year 4. Fertilization had a consistently positive effect on radial stem increments and N content of foliage, regardless of the presence of moss on the plot. Overall, the intraspecific competition between trees was apparently greater than interspecific competition between moss and trees.     

The effect of weed control and fertilization on survival and growth of four pine species in the Virginia Piedmont

The growth response of loblolly pine (Pinus taeda L.), shortleaf pine (Pinus echinata Mill.), Virginia pine (Pinus virginiana Mill.), and white pine (Pinus strobus L.) to weed control and fertilization in the Piedmont of Virginia was assessed. Four different silvicultural treatments were evaluated: (1) check (no treatment); (2) weed control; (3) fertilization; (4) weed control plus fertilization. The weed control treatment included a series of herbicide and mechanical treatments to eliminate competing hardwoods. The fertilizer treatments added N, P, K, and S. Survival and growth was measured annually through age 5. There were significant differences in survival and growth among species. Survival was greatest for loblolly pine, lower in shortleaf and Virginia pine, and lowest in white pine. Fertilization without controlling the competing hardwoods decreased survival in all planted pines due to the increased hardwood competition. Loblolly pine was tallest through the 5-year period, shortleaf and Virginia pine were shorter and white pine was shortest. Silvicultural treatments had no impact on tree height but significantly affected DBH. Weed control increased DBH while fertilization did not. When applied in combination with weed control, there was no additional increase in growth of the pines due to fertilization beyond that from weed control only. Fertilization stimulated the growth of the competing hardwoods which were significantly taller in the fertilized plots.     

杉木幼林施肥肥效分析

在肥力中等的酸性红黄壤上，采用随机区组设计，对１年生杉木幼林进行７个处理、３次重复的施肥试验。结果表明，施肥对杉木幼林树高、抽高和胸径虽有影响，但效果均不显著；钙镁磷肥、磷酸铵及过磷酸钙肥效相当，沟施肥效好于穴施。施肥能影响杉木各器官的生物量，影响大小顺序依次为叶、干、枝、根；沟施磷酸铵对树叶生长量有极显著的影响，并对生物总量影响显著。协方差分析显示杉木幼林施肥时的初始树高会干扰肥效，特别对施肥当年树高的影响显著，肥效分析时必须进行修正以消除其影响。     

秃杉人工林施肥效应试验初报

采用不同肥料种类和施肥剂量对秃杉人工林进行施肥对比试验。观测胸径、树高和蓄积生长量,分析不同肥料种类和施肥剂量对秃杉人工幼龄林高、粗和蓄积生长量的效应。试验结果表明,合理的施肥措施对秃杉人工林生长有明显促进作用,与对照相比,年高生长增加34%,粗生长增加26%,蓄积生长增加35%。     

Fertilization of Danish Forests: A Review of Experiments

Fertilization experiments in Norway spruce stands on nutrient-poor sites have been practised in Denmark since the eighteenth century. Until 1950, the main aim was to find a nitrogen (N) source that improved the survival of plants in the early growth phase. The N supply could be improved by intercropping with N 2 -fixing plants, and fertilization with phosphorus (P) and potassium (K) improved the growth of the N 2 fixers, thereby improving tree growth and survival. Positive responses of P and K in spruce cultures were seen in the 1960s, and in most cases the N response was dependent on the supply of P and K. Fertilization experiments in mature spruce stands began in the 1960s. Despite 20 yrs of experimentation, no trends can be deduced. The results discouraged fertilization aimed at increasing growth in mature stands, and fertilization stopped in 1989. After 1980, fertilizers were used in experiments aimed at clarifying the causes and effects of forest decline. Fertilization and liming counteracted soil acidification and increased needle nutrient concentrations when they were below deficiency levels. However, positive growth responses have only been recorded in some of the experiments where nutrient deficiencies were overcome. The experiments have not resulted in practical revitalization programmes. Future fertilization of Danish forests may be limited to systems where nutrient extraction is in excess of the carrying capacity of the ecosystem, and presumably where spruce plantations are converted to broadleaved forests. Finally, future events of deposition of acidifying compounds may necessitate counteractive measures.