共查询到20条相似文献，搜索用时 531 毫秒
1.
O. Schmidt D. Dujesiefken H. Stobbe U. Moreth R. Kehr Th. Schröder 《Forest Pathology》2008,38(2):124-128
Bacteria were isolated from necrotic lesions on a horse chestnut tree (Aesculus hippocastanum) with bleeding canker in Hamburg, Germany. Sequencing of the rDNA-ITS region revealed great similarity to pathovars of Pseudomonas syringae. Pseudomonas syringae pv. aesculi was identified by sequence homology of the gyrase B gene. This is the first report of P. syringae pv. aesculi in Germany. Phytophthora was not detected. 相似文献
2.
Dr. U. Sellenschlo 《Journal of pest science》1986,59(7):122-125
A new key to known the larvae ofReesa vespulae and ofTrogoderma spp. in Germany and surrounding countries is concipated. Mistakes from old publications are corrected. 相似文献
3.
The commitment to report greenhouse gas emissions requires an estimation of biomass stocks and their changes in forests. When this was first done, representative biomass functions for most common tree species were very often not available. In Germany, an estimation method based on solid volume was developed (expansion procedure). It is easy to apply because the required information is available for nearly all relevant tree species. However, the distributions of neither parameters nor prediction intervals are available. In this study, two different methods to estimate above-ground biomass for Norway spruce (Picea abies), European beech (Fagus sylvatica), and Scots pine (Pinus sylvestris) are compared. First, an approach based on information from the literature was used to predict above-ground biomass. It is basically the same method used in greenhouse gas reporting in Germany and was applied with prior and posterior parameters. Second, equations for direct estimation of biomass with standard regression techniques were developed. A sample of above-ground biomass of trees was measured in campaigns conducted previously to the third National Forest Inventory in Germany (2012). The data permitted the application of Bayesian calibration (BC) to estimate posterior distribution of the parameters for the expansion procedure. Moreover, BC enables the calculation of prediction intervals which are necessary for error estimations required for reporting. The two methods are compared with regard to predictive accuracy via cross-validation, under varying sample sizes. Our findings show that BC of the expansion procedure performs better, especially when sample size is small. We therefore encourage the use of existing knowledge together with small samples of observed biomass (e.g., for rare tree species) to gain predictive accuracy in biomass estimation. 相似文献
4.
Mitigating international trade in illegally harvested wood (products) is an international priority. To support this priority, the European Timber Regulation prohibits placing illegally harvested or traded timber on the EU market, requiring companies to undertake due diligence in sourcing wood (products). To take effect, this regulation needs to be implemented in all European member states.Although Germany is one of the first member states to transpose and enact the regulation's provisions, its implementation has recently been portrayed as “weak” and ineffective. This article aims to answer why this perception emerged. It scrutinizes implementation performance of the EUTR in Germany.Based on rich empirical data from stakeholder interviews, documents, and participant observation, this study argues that EUTR performance in Germany is not generally perceived as ineffective. Instead, stakeholder perceptions vary. As stakeholders face major uncertainties connected to market structure and company behaviour, they tend to base their assumptions about the implementation process on two major heuristics. Both focus on the question how to change company behaviour. One stresses the need to pursuade companies to comply, the other stresses the need to coerce them. These heuristics are based on the two larger objectives pursued by different stakeholder groups during policy making of the EUTR: (1) global sustainable forest management and (2) image improvement of the EU wood importing industry.Based on these different policy objectives, the EUTR does not provide clear guidance on which policy instruments should be given priority. As a consequence, national implementation is turned into a policy-making process. The outcome of this struggle will likely affect the future trajectory of EUTR implementation in other EU member states and in countries exporting wood into the EU. 相似文献
5.
U. Mielke 《Journal of pest science》1998,71(5):94-95
Among the five synanthropic cockroach varieties occuring in Germany, the Australian cockroach (Periplaneta australasiae) is the most infrequent species, it does represent a rarity. Its current distribution in Germany was investigated in 1996/97. Zoological and botanic gardens, with their hothouses offering optimal living conditions for this roach variety, were found to be focal sites of infestation. Similarly, a swimming bath facility and a museum were noted to be infested withP. australasiae for a lengthy period. In addition, few isolated sites of incidence were noted. The present work is a first time ever attempt to gain an overview of the incidence of Australian cockroach in Germany. The Australian cockroach is of no relevance as a public health pest in Germany. 相似文献
6.
Herbert Weidner 《Journal of pest science》1967,40(2):17-22
Summary Insects can be imported by ships in ballast, cargoes, woodwork and residues of former shipments in corners and clefts. There
are given examples for noxious insects on cargoes. Termites, perhaps Cryptotermes sp. have destroyed harmonicas being transported
from Germany to South Africa. The winged adults of Cryptotermes brevis (Walker) swarmed out of woodwork of cabin for wireless
telegraphy on a Westindian steamer arriving the port of Hamburg June 1966. On the voyage to Chile Tribolium castaneum (Herbst)
could attack soup meal made in Germany by Solenopsis geminata F. biting through the metallic foil of multiwall bags. Young
larves of Dermestes maculatus Deg. gnawed at goats skin of native drums from Mombassa. The infection of copra by Periplaneta
americana L. is discused and a case of butterfly itch by Hylesia canitia Stoll reported.
相似文献
7.
H. J. Spahr 《Journal of pest science》1981,54(2):27-29
It is the purpose of this study to determine the suitability of arthropods living on the ground for ecotoxicological tests, so that subacute toxicity tests may be carried out in them. Among these, also Collembola are tested for the suitability. They belong to the group of primarily wingless insects (Apterygota) having a length of 0.5 to 5 mm. They are slightly sclerotized and mainly living on the ground. As test organisms they meet the following requirements:
- Presence in all types of soil (Collembola live, very often in great numbers, on any soil in any climate).
- Importance for soil biology (due to their great number and their omnivorous way of nutrition they play a considerable role in the treatment and transformation of wastes of vegetal origin).
- Easy breeding (so that they are constantly available for tests; many species of Collembola are easy to breed, may be bred in large quantities and at relatively low expenditure on time and equipment).
- Short period of development and high reproduction rate (primarily, the smaller species of Collembola have short periods of development and high reproduction rates when adequate temperatures are maintained).
- Controllability (which is guaranted by appropriate selection and conservation methods).
8.
Summary Crosslinking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour and its resistance against microorganisms. However, this formaldehyde crosslinking reaction takes place only in the presence of an acid catalyst, which results in losses in mechanical strength. Electron microscopic analysis of poplar samples treated under various conditions of reaction revealed severe degradation of cell wall substances. The formaldehyde gaseous nonomer is shown to have some hydrolytic action on cellular structure. Sulphur dioxide and particularly hydrochloric acid used as catalysts caused substantial extraction of matrix substances from fibre walls. Walls of vessels and ray parenchyma cells seemed to become less degraded. Strong exposure of cellulose fibrils during formaldehyde crosslinking reactions, illustrated by highly electron transparent zones in the S1 and inner S2 layers, occurred for both the SO2 and HCl catalyzed treatments. In general a more extensive degradation was observed for the formaldehyde-hydrochloric acid reaction and for the formaldehyde sulfur dioxide treatments using a high acid concentration. From these observations it might be concluded that the reduced mechanical strength of formaldehyde-treated woods are partially based on the hydrolysis of the carbohydrate backbone of the cell wall.The senior author wishes to express his gratitude to the F.V.S.Stiftung in Hamburg (Federal Republic of Germany) for the grant of a Justus-von-Liebig Reisestipendium. He is also indebted to Prof. Dr.W.LLiese for the opportunity to work in the Institut für Holzbiologie und Holzschutz der Bundesforschungsanstalt für Forst-und Holzwirtschaft, Hamburg 相似文献
9.
Studies conducted in the 2000 cropping season at two different localities, Flaeming and Magdeburger Boerde in Germany, have provided new information on cereal aphid (Sitobion avenae (F.), Metopolophium dirhodum (Walker), and Rhopalosiphum padi (L.)) parasitoids in winter wheat; their species composition, relative abundance, hosts, and location effects. The average aphid population density was higher at Magdeburger Boerde and lower at Flaeming. Among the aphid species, Sitobion avenae was more abundant at Flaeming and Metopolophium dirhodum at Magdeburger Boerde. In total, eight species of primary parasitoids were recorded: Aphidius colemani Viereck, Aphidius rhopalosiphi DeStefani Perez, Aphidius uzbekistanicus Luzhetzki, Aphidius ervi Haliday, Aphidius picipes (Nees), Ephedrus plagiator (Nees), Praon gallicumStarý, and Praon volucre (Haliday). The predominant parasitoid species were Aphidius colemani and Aphidius rhopalosiphi on Metopolophium dirhodum and Aphidius uzbekistanicus on Sitobion avenae. A low number of hyperparasitoids were also recorded. Aphidius colemani was recorded for the first time in the open winter wheat fields in Germany, although it has been used as a biocontrol agent in glasshouses in many European countries and overseas. An analysis of the aforementioned information shows that Aphidius colemani detected as a parasitoid of cereal aphids in Germany is likely a result of an accidental escape of parasitoids from a glasshouse, as well as their successful overwintering and establishment in the area. This study provides baseline information essential for assessing future changes in aphid parasitoid species guild and dynamics in cereal fields in Germany. 相似文献
10.
In 1998, a survey of scale insects infesting grapevine (Vitis vinifera) in southwestern Germany yielded four species, namelyHeliococcus bohemicus, Parthenolecanium corni, P. persicae andPulvinaria vitis. P. persicae is recorded for the first time in Germany. The last surveys on scale insects in southwestern Germany were conducted byWünn (1925, 1926) but at this timeP. persicae was not discovered yet in this region. Most probably the thermophilus species immigrated from Swizerland and spread northwards into the Rhine valley during the last two or three decades of years.P. persicae is attacked by four species of parasitoids and a hyperparasitoid. The most common species is the encyrtidBlastotbrix bungarica. 相似文献
11.
Summary Kraft and ethanol organosolv lignins from Picea abies and Fagus sylvatica were carboxymethylated with bromoacetic acid. Of the total hydroxyl groups in the lignins, 60–70% were carboxymethylated. The reaction led to an increase of the number-average molecular weights. The moisture adsorption of the carboxymethylated products is about one and a half as high as that of the original lignins. There are no remarkable differences between the solubilities of the treated and untreated products.The authors wish to express their appreciation to Mr. Dietrich Meier, Federal Research Organization for Forestry and Forest Products, Hamburg, Federal Republic of Germany, for preparation and donation of lignin samples 相似文献
12.
国外林区道路发展现状及启示 总被引：4，自引：2，他引：2
林区道路是林业和区域发展不可或缺的基础设施。德国、奥地利等较早实现工业化的欧洲国家林道建设起步早, 现已形成了与本国林业生产作业体系相适应的完善的林道路网体系。奥地利林道密度已达到89 m/hm2, 德国超过100 m/hm2, 英国、法国、美国、加拿大、澳大利亚和新西兰等国家也具备了密集的林道路网体系, 而日本、印度、韩国和俄罗斯林道配置水平较低。文中概述了这些国家林区道路的发展现状和经验教训; 针对我国林区道路总量不足、等级低下等严重滞后问题, 提出合理提高林区道路密度和等级, 林道建设要科学规划合理配置、重视森林生态保护, 制定林道建设技术标准和规程, 减少对环境的负面影响等建议。 相似文献
13.
Overview of methods and tools for evaluating future woody biomass availability in European countries
Susana Barreiro Mart-Jan Schelhaas Gerald Kändler Clara Antón-Fernández Antoine Colin Jean-Daniel Bontemps Iciar Alberdi Sonia Condés Marius Dumitru Angel Ferezliev Christoph Fischer Patrizia Gasparini Thomas Gschwantner Georg Kindermann Bjarki Kjartansson Pál Kovácsevics Milos Kucera Anders Lundström Gheorghe Marin Gintautas Mozgeris Thomas Nord-Larsen Tuula Packalen John Redmond Sandro Sacchelli Allan Sims Arnór Snorrason Nickola Stoyanov Esther Thürig Per-Erik Wikberg 《Annals of Forest Science》2016,73(4):823-837
14.
Generalist arthropod predators are potential drivers of population dynamics in a wide variety of ecosystems but their feeding
habits are often difficult to reveal as they are small, mobile, and live among dense vegetation or in soils. DNA-based gut-content
analysis is a powerful tool that enables studies on arthropod predator–prey interactions. We studied lycosid spiders (Pardosa spp.) in agroecosystems to see if they consumed cereal aphids (Rhopalosiphum padi) and Collembolans at random, i.e., in proportion to their abundance in the field. We also tested if consumption of the target
prey items was affected by the presence of alternative food. Spiders were captured in farmers’ fields and their gut-contents
screened by PCR with R. padi and Collembola primers. On all sampling occasions, concurrent assessments of total prey availability were carried out. Spider
predation rates on R. padi always exceeded 50 %. Spiders also tested positive for Collembola but to a lower and more varying degree. In general, Pardosa did not consume R. padi and Collembolans in relation to their abundance in the field. Aphid predation was much higher than expected whereas consumption
of Collembolans was considerably lower. The presence of alternative prey influenced consumption of the aphid. It was concluded
that prey consumption by Pardosa spiders generally cannot be assumed to simply mirror prey availability. The spatial distribution of the target prey needs
to be considered as well as the abundance, composition, and nutritional content of potential alternative food items. 相似文献
15.
Dr. rer. nat. U. Mielke 《Journal of pest science》1995,68(8):187-189
The in houses living cockroachSupella longipalpa Fab. was found in Germany for the first time in 1954 (Peters, 1956). A view is given on the localities of findings until 1994/5. From this is to be seen that this pest shows a pronounced insular distribution. For controlling specific measures must be applied. 相似文献
16.
Camptothecin (CPT), 9-methoxycamptothecin (9-MeO-CPT), and 10-hydroxycamptothecin (10-OH-CPT) are potent antineoplastic metabolites. We analyzed these metabolites in Camptotheca acuminata sampled from Germany and China, using LC-MS/MS and LC-ESI-HRMS/MS, coupled with chemometrics. Multivariate analysis revealed that fresh stems of C. acuminata from China had the highest comprehensive metabolite load. Significant positive correlations of CPT with 9-MeO-CPT and 10-OH-CPT were observed by Kruskal's multidimensional scaling and principal component analysis. Linear discriminant analysis and hierarchical agglomerative cluster analysis revealed that C. acuminata from China was separated from others. These positive correlations indicate that these metabolites are biosynthesized similarly and operate synergistically in planta. 相似文献
17.
The forests of Austrocedrus chilensis (D. Don) Pic. Sern. et Bizarri in Argentina suffer decline and mortality throughout their natural distribution known as ‘mal del ciprés’. While several aspects of this, to date, temporally unpredictable process of overstory tree mortality have been the focus of detailed studies, there has been little research on tree growth and stand dynamics in symptomatic forests nor stand development patterns and prediction of future stand structure. We studied 12 stands in northern Patagonia (Province of Río Negro) using stand reconstruction studies to examine the changes in stand structure over time as a consequence of overstory mortality and the implications of these structural changes on the establishment and growth of the residual overstory. Dendrochronological analyses were used to reconstruct stand establishment and structure over time, and to study past diameter growth patterns. Mortality in A. chilensis forests was variable in time among stands. As expected, overstory mortality led to the successful establishment of trees in the understory in all stands; however, the response of residual overstory trees was variable. Understory establishment was low in some stands and high in others depending on the density of the overstory. While overstory trees in almost all stands released after the onset of the mortality, the pattern was not distinctive, varying in time, number and magnitude. In some stands, growth releases occurred after single or multiple tree deaths suggesting a relationship between processes, while in others this was not the case. Even when the patterns of recruitment in the understory and the overstory response varied greatly among stands, when examined together, some general patterns emerged. This study is the first to intensively explore the dynamics of A. chilensis forests affected by ‘mal del ciprés’. Additionally, this study showed that arbitrarily categorizing disturbances as discrete or chronic masks the true process of release of growing space and the resulting stand dynamics. 相似文献
18.
Ferenc Lakatos Wojciech Grodzki Qing-He Zhang Christian Stauffer 《Journal of Forest Research》2007,12(5):345-349
The distribution of the double spined spruce engraver beetle Ips duplicatus ranges from Scandinavia and northeastern Europe to northern Asia. In Europe, I. duplicatus usually is associated with I. typographus on Picea abies, and due to morphological similarities and similar gallery constructions the damage and significance of I. duplicatus are often not recognised and thus underestimated. I. duplicatus has been recently reported from the southern part of Poland, the Czech Republic, Slovakia, northern parts of Austria and
Germany; records are missing from many other central European countries (e.g., Hungary). The species became an important pest
in some parts of central Europe, and continuous outbreaks of this bark beetle have been reported in Inner Mongolia, China,
since the 1950s. The aim of this study was to compare I. duplicatus populations from Europe and Asia by genetic means using the analysis of the mitochondrial DNA. Individuals of I. duplicatus populations from China, Poland, the Czech Republic and Slovakia were collected, and 520 bp fragments of the cytochrome oxidase I (COI) gene were analysed. Four haplotypes were detected and a sequence divergence of 0.8% was found between the populations
from China and Europe. These differences associate with behavioural differences in the pheromone bouquet and behavioural response
of the two groups. Within Europe three haplotypes were found, but due to the small sample size no significant geographical
distribution was demonstrated. 相似文献
19.
20.
The conversion of even-aged Norway spruce (Picea abies (L.) H. Karst.) stands into more site adapted mixed stands is the main silvicultural goal in Germany and many other European countries. The conversion will primarily be achieved with the help of selection cutting, removing single target diameter trees and creating small gaps. At sites highly susceptible to windthrow, however, small scale clear cutting (up to 1 ha) might be an appropriate alternative. Both selection and clear cutting will affect the understorey vegetation, an important component of forest biodiversity and ecosystem functioning. Thus, with the help of a BACI-experiment (before–after/control–impact), the short-term effects of selection and small scale clear cutting on the herb and shrub layer vegetation were studied at two sites in the Solling Hills (Lower Saxony, Germany). Both treatments led to an increase in herb and shrub layer species numbers, due to persistent and invading (mainly pioneer tree species and indicators of disturbance) species and to a shift in plant traits. Most responsible for the changes in vegetation was a higher light availability, and to a lesser degree soil disturbance. The number of annuals and ruderals, however, increased only immediately after clear cutting, whereas on selection cutting plots the numbers remained high. Gaining in number and coverage were competitive perennials (Epilobium angustifolium, Juncus effusus, Rubus idaeus) especially on the clear cuttings, fulfilling a nutrient retention function. The competitives did not deter tree species from regenerating in the clear cut plots, whereas on selection cutting plots the large expansion of R. idaeus appeared to be hindering tree colonisation. Suffering under clear cut conditions were predominantly shade-tolerant, closed-forest species, but no loss of these species could be detected. This indicates the potential for a fast recovery of these forest species, as soon as, pioneer trees expand. 相似文献