闽南林业苗圃果尔化学除草技术研究

研究了在福建省泉州地区林业苗圃应用果尔化学除草的适宜剂量、施药时间、施药方法、经济效益和推广价值。结果表明：以７５０ｍｌ／ｈｍ￣２剂量的果尔在杉、松和火力楠等苗木圃地，采用喷雾或药土法施药，对窄、阔叶杂草的防除效果达９０％以上，比人工除草省工８０％以上，节省资金７２％以上；对苗木安全，已在全市林业苗圃推广。     

林业苗圃系列化学除草应用试验

林业苗圃系列化学除草应用试验宋战友（三岔子林业局）杂草是林业苗圃中育苗的大敌，杂草不但与苗木争水、争光、争养分，而且还是传播病虫害的媒介，妨碍着苗木生长。在育苗生产中，人工除草效率低、成本高。根据我们近几年统计，人工除草占苗圃总用工量的５７％。为适应...     

23.5%果尔乳油、10.8%盖草能乳油在苗圃化学除草中的应用

化学除草是林业苗圃经营管理的一项先进技术。这项技术不仅效果好、成本低 (节省费用 50 % ) ,还能大大提高劳动生产率。果尔、盖草能杀草谱广、活性高、用量少、持效期长 ,对苗木具有选择性 ,对人畜及野生动物安全 ,是苗圃化学除草的优良除草剂。现将苗圃使用果尔、盖草能化学除草技术简介如下 :1　播后苗前处理苗圃作床、播种 ,由于已经多次翻耕 ,一些深埋在土底层的各种杂草种子 ,将被暴露于土表 ,并随温度升高而不断发芽出土 ,而林木种子尚处于吸水膨胀阶段 ,有种壳保护 ,尚未出土。播种覆土后 ,可用果尔每 6 6 7ｍ2 商品量 50～ 80ｍｌ…     

几种主要苗木的化学除草技术

苗圃化学除草是苗圃经营管理的一项先进技术,具有使用方便、效果好、除草持效时间长、高效、经济、低毒、低残留、对人畜安全等特点。在一些发达的国家已广泛应用这一技术。我国近年来也开始较多地采用。普及林业苗圃化学除草技术已成为当今林业苗圃经营管理中的重要技术之一。下面将几种主要苗木的除草技术简介如下：     

苗圃化学除草实用技术系列报道之Ⅳ

2 .5　油茶、茶树苗圃化学除草技术2 .5 .1　苗圃化学除草的原则(1)由于油茶、茶树叶面较厚 ,具有较强的耐药性 ,对一些内吸传导性除草剂如草甘膦 ,具有较强的抗性 ,有利于防除苗圃中的一些多年生深根性杂草 ,所以尽可能用草甘膦针对性喷雾作叶面处理 ,进行除草。(2 )油茶、茶树是直根系 ,主根发达、侧根、须根较小 ,对一些残留性较强的除草剂都可在苗圃里使用。2 .5 .2　化学除草技术播后苗前处理　由于种子大 ,覆土厚 ,苗木带壳出土 ,可用果尔每6 6 7ｍ2 有效量 10～ 15ｇ或用拉索每6 6 7ｍ2 有效量 130ｇ ,或用西玛津每6 6 7ｍ2 有效量 5…     

北方林业苗圃化学除草技术

林业苗圃化学除草剂使用方便、高效、经济、对人畜安全。该文就林业苗圃化学除草剂的主要作用原理、部分主要苗木的化学除草技术、应用效果及使用除草剂应注意的事项进行了综述。     

《林业苗圃化学除草指南》

林业化学除草专家陈国海教授主编的新版《林业苗圃化学除草指南》一书，现已由学苑出版社出版发行。本书详细介绍了林业苗圃化学除草基本知识、除草剂品种及剂型选择、林业苗圃化学除草技术和试验方法、苗圃喷药机械及其调整使用等有关方面的技术。     

乙氧氟草醚在东北森林苗圃的应用

乙氧氟草醚活性高、杀草谱广，对苗木安全，不影响下茬植物的种植；广泛适用于东北主要针叶树种和部分阔叶树种苗圃除草，可降低人工除草费用50％～70％，提高工效10倍以上，提高了苗木的产量和质量。现将我们10多年来使用乙氧氟草醚化学除草方法简介如下：     

林业化学除草新动向

林业化学除草是一门技术性很强的学问。它具有选择性强、除草效果好、持续期长、节省人力和物力的优点。有些激素类除草剂对苗木的生长还具有刺激作用,可促进苗木的生长。因此,林业化学除草技术正日益受到广泛重视,在林业生产的各个环节均发挥着愈来愈重要的作用。目前,在直播造林整地、幼林抚育、森林苗圃除草、林分改     

乙草胺除草剂圃地使用技术

苗圃杂草生长快、种类多、数量大,人工除草不仅劳动强度大、成本高,而且还易使幼苗根系松动,妨碍苗木正常生长。苗圃地化学除草,油茶、板栗等苗圃地试验,每亩施乙草胺60～75毫升,对苗木安全,除草效果达95％以上,持效期30～60天。比人工除草,省工85％以上,节约费用87％以上,而且施药操作简单,不污染环境。     

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.