丰台区国槐病虫害防控的实践研究

随着北京市丰台区园林的逐渐建成,后期养护逐渐成为园林的重点工作,城市园林中的病虫害问题也日益凸显。通过调查统计和数据分析,为丰台区有效减轻锈色粒肩天牛对国槐的影响、国槐病虫害防控提供基础分析依据。以北京市丰台区为例,通过实地调查和样本收集,详细记录了锈色粒肩天牛与国槐的生长数据,并进一步对数据进行了统计分析。揭示了锈色粒肩天牛的侵害模式及其与环境因素的关联性;通过样本数据,构建了锈色粒肩天牛的虫株率与国槐胸径、虫口密度与国槐死树率、气候因素与国槐虫害发生率之间的关系,并拟合了这种关系的函数方程。结果表明：锈色粒肩天牛的侵害与国槐的胸径呈明显正相关,尤其胸径为20～25 cm的国槐受害最为严重,有虫株率达到12.45%,虫口密度为1.74头/株。此外,树木的生理状况、枝干方位,以及气候因素也与虫害的发生密切相关。     

锈色粒肩天牛危害洛阳市区国槐的调查与分析

对洛阳市主要街道、公园和居民区的国槐受锈色粒肩天牛危害的状况进行调查的结果表明：锈色粒肩天牛对王城公园国槐树的危害最为严重，对中州西路2街道国槐树的危害最轻；锈色粒肩天牛在不同方位枝上的分布无明显差异。     

抗锈色粒肩天牛国槐优株的遴选

通过对莒县、滕州、巨野、曲阜等地千余株国槐受锈色粒肩天牛危害状况及程度的调查,在兼顾树高、干形、冠幅等型质指标的条件下,遴选出高抗锈色粒肩天牛国槐优株3棵。     

锈色粒肩天牛生物学特性及防治措施

锈色粒肩天牛目前是国槐主要钻蛀性虫害。该文在调查锈色粒肩天牛在汝阳县分布及危害程度的基础上,详细介绍了其发生与危害、形态特征、生物学特性及综合防治措施。     

锈色粒肩天牛幼虫在国槐树干上的分布及虫口预测模型

通过解剖国槐Sophora japonica受害木,结合林间调查,分析锈色粒肩天牛Apriona swainsoni幼虫在国槐树干上的分布,建立幼虫虫口数量预测数学模型。结果表明,锈色粒肩天牛幼虫主要分布于国槐主干2 m以下的位置,中、老龄幼虫主要危害寄主的边材部位。以新排粪孔与解剖木实际带虫数量建立4个虫口预测模型方程,经方差检验均可靠有效。     

锈色粒肩天牛的生物学观察及防治

锈色粒肩天牛的生物学观察及防治锈色粒肩天牛Ａｐｒｉｏｎａｓｗａｉｎｓｏｎｉ（Ｈｏｐｅ）为国内检疫对象，国内主要分布于长江以南几个省，危害国槐、黄檀等树种，尤以国槐为重。传入我省后，蔓延速度较快，１９９５年抽样调查，沂水县内国槐有虫株率高达９０％，单株...     

锈色粒肩天牛侵入孔、羽化孔在国槐上分布规律的研究1

通过对不同样地国槐上锈色粒肩天牛的侵入孔、羽化孔分布规律的研究表明：在国槐的基部有植被和绿篱的样地锈色粒肩天牛的侵入孔、羽化孔主要集中在0.5 m以下,占总侵入孔和羽化孔的89.29%和66.67%;无植被的国槐锈色粒肩天牛的侵入孔主要分布在树干基部2米以下,侵入孔率随树龄的增大而减少;从分布方位上看,主要集中在东南两侧。无植被的样地羽化孔主要集中在1.米以上,羽化孔率随树龄的增大而增大,从分布方位上看羽化孔多集中在东南方向。     

锈色粒肩天牛与寄主树种关系的初步研究

在连续 3a的定位观测和分析基础上 ,本文初步报道了锈色粒肩天牛与文献报道中的几种寄主树种之间的关系。结果如下 :(1)根据室内饲养下成虫对不同树种的取食及产卵情况和在不同树种上接种 (卵 )的幼虫情况 ,可将几种寄主树种分为 4类 :高感树种 (国槐 )、低感树种 (云实、黄檀 )、抗虫树种 (刺槐 )、免疫树种 (旱柳 ) ;(2 )酚酸类物质在旱柳中的含量 (3 0 3～ 9 73mg·(10 0g) - 1 ) ,显著高于其它树种中的含量 (1 71～5 39mg·(10 0g) - 1 ) ,可能是锈色粒肩天牛在旱柳上表现拒食、拒产卵、拒钻蛀的重要原因。氨基酸含量较高、组分相对最全 (17种 ) ,以及较高的C N值 ,是国槐基本营养物质的显著特征 ,这可能是锈色粒肩天牛嗜食国槐 ,对其造成严重危害的根本原因。锈色粒肩天牛很少取食危害刺槐 ,这与刺槐树种的各部分C N值过低 ,造成营养失调有关。黄檀木材纤维平均长度为 0 837mm ,平均宽度为 18 90 μm ,长宽比为 5 0 96 ,其韧性是参试树种中最大的 ,因而可能造成幼虫啃食困难 ,加上木材中的C N低 (0 36 ) ,因此 ,具有较强的抗虫性。云实树皮薄而光滑 ,造成成虫产卵困难 ,因此 ,在自然状态下 ,锈色粒肩天牛不易对其产生危害。     

锈色粒肩天牛侵入孔、羽化孔在国槐上分布规律的研究

通过对不同样地国槐上锈色粒肩天牛的侵入孔、羽化孔分布规律的研究表明:在国槐的基部有植被和绿篱的样地锈色粒肩天牛的侵入孔、羽化孔主要集中在0.5 m以下,占总侵入孔和羽化孔的89.29%和66.67%,无植被的国槐锈色粒肩天牛的侵入孔主要分布在树干基部2米以下,侵入孔率随树龄的增大而减少;从分布方位上看,主要集中在东南两侧.无植被的样地羽化孔主要集中在1.米以上,羽化孔率随树龄的增大而增大,从分布方位上看羽化孔多集中在东南方向.     

锈色粒肩天牛预测预报研究

近年来,锈色粒肩天牛在定陶县国槐树上普遍发生,受害严重的片林或路段,国槐虫株率达95%以上。受害树木轻者影响生长,木材价值降低,重者全株死亡。为了搞好锈色粒肩天牛的防治工作,我们在研究该虫生物学特性的同时,于1995～1997年对其预测预报进行了探讨。1　研究方法于19...     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.