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1.
在阿拉善左旗境内选取5个试验区,观测不同时期春季造林和秋季造林新梢生长长度、地径大小、冠幅大小及苗木成活率。结果表明:各试验区内春季造林和秋季造林苗木生长量和成活率的表现规律较一致;春季造林,苗木在进入生长季后,生长缓慢,到6月后,生长速度开始加快,但与秋季造林的苗木生长量差异显著(P0.05),秋季造林苗木生长量显著高于春季造林生长量,而且,秋季造林成活率也显著高于春季造林成活率。因此,本地区适宜秋季造林。  相似文献   

2.
在大兴安岭林区的干旱阳坡火烧迹地进行了整地方式、苗木T/R比、造林季节和保苗剂应用对造林成活率影响的研究。结果表明:鱼鳞坑整地能够降低土壤温度,增加土壤含水率,进而提高樟子松苗木造林成活率;随着苗木T/R比的降低,樟子松苗木造林成活率增加;樟子松和落叶松苗木春季造林成活率均高于秋季;使用HRC保苗剂后樟子松和落叶松苗木造林成活率平均增加13.7个百分点。  相似文献   

3.
为研究降香黄檀不同种苗类型及不同季节造林与林分生长关系,对宜宾地区的降香黄檀林分生长性状调查分析,结果表明:扦插苗造林的林分在幼林期生长速度要快于实生苗造林林分,扦插苗造林表现出更好的适应能力;春季造林和秋季造林的成活率都在90%以上,但春季造林(97.87%)的效果明显好于秋季造林(94.33%);实生苗木在春季或秋季造林对林分的树高、胸径、冠幅等性状生长影响不显著。  相似文献   

4.
在广西国有维都林场进行红椎纯林、杉木纯林、“红椎+杉木”混交林(5∶5行状混交)早期生长量对比试验,结果表明,杉木纯林、红椎纯林、“杉木+红椎”混交林的成活率、保存率皆超84%以上,不同造林模式对树种成活率、保存率无显著影响;混交林杉木的平均树高较纯林增长13.11%,平均胸径增长9.13%;混交林红椎的平均树高、平均胸径分别比纯林增长2.03%、36.65%;混交林中红椎、杉木生长值皆超过相应树种的广西壮族自治区地方标准规定的生长指标。采取杉木与阔叶树红椎混交造林,对杉木、红椎的早期生长量均有促进作用。  相似文献   

5.
沙区气候环境条件恶劣,特别是近年气候变化异常,致使沙区造林成活率较低。试验得出:整地比未整地地块造林成活率提高17.09个百分点;整地秋季埋根造林比翌年春季植干造林成活率提高6.3个百分点;未整地秋季埋根造林比翌年春季植干造林成活率提高9.3个百分点;实施林农复合经营是非常有效的一种抚育方式;采伐迹地造林,整地是造林成败的关键环节,通过农事活动整地,可及时清除伐根,改善地力。  相似文献   

6.
通过对干旱山区不同季节山杏造林后的生长情况调查分析,得出:秋季山杏截干深栽造林成活率达92.7%,比春季栽植成活率提高10.5个百分点。  相似文献   

7.
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。  相似文献   

8.
近几年来,承德市在荒山绿化美化中采用黄栌造林,不仅加速了荒山绿化步伐,而且由于黄栌秋季叶色红艳,起到了美化效果。按照传统的造林方法,黄栌采用春季和夏季截干造林。但由于承德市范围内春季雨水较少,天气干旱影响造林成活率。而夏季造林必须采用2年生苗,造林后生长量小,成活率低,同时育苗时间长,加大了育苗和造林成本。  相似文献   

9.
通过对景泰地区影响造林成活率和保存率效果因子分析和对实地试验观测研究,得出西北干旱荒漠区春季造林成活率低于秋季造林,但是春季造林保存率高于秋季造林。  相似文献   

10.
2013年3月,将1年生南方红豆杉Taxus chinensis var.mairei,浙江楠Phoebe chekiangensis和闽楠P.bournei无纺布袋苗种植于浙江省缙云县,进行村道路旁种植、杉木Cunninghamia lanceolata采伐迹地造林和马尾松Pinus massoniana林下补植3种造林方式的比较试验。2013年10月和2015年2月的调查结果表明,南方红豆杉当年成活率和3 a保存率间没有明显的差异,但以迹地造林的平均地径和平均树高生长最低;浙江楠的当年存活率、3 a保存率以及平均地径和平均树高生长均是迹地造林最低,林下补植最高;闽楠当年存活率和3 a保存率间没有明显的差异,但是3 a保存率以及平均地径和平均树高生长均以迹地造林最低,路旁种植最高。试验结果表明,3种珍贵树种均不适合迹地造林。  相似文献   

11.
A dramatic decline in forest cover in eastern Africa along with a growing population means that timber and poles for building and fuelwood are in short supply. To overcome this shortage, the region is increasingly turning to eucalyptus. But eucalyptus raises environmental concerns of its own. Fears that it will deplete water supply, affect wildlife and reduce associated crop yields have caused many countries in the region to discourage farmers from planting this exotic. This paper is part of a series of investigations on the growth and water use efficiency of faster growing eucalyptus hybrids, which was introduced from South Africa to Kenya. The hypothesis is that the new hybrids are more efficient in using water and more suitable for the semi-arid tropics than existing eucalyptus and two popular agroforestry species. Gas exchange characteristics of juvenile Eucalyptus grandis (W. Hill ex Maiden), two eucalyptus hybrids (E. grandis × Eucalyptus camaldulensis Dehnh.), Grevillea robusta (A. Cunn) and Cordia africana (Lam) was studied under field and pot conditions using an infrared gas analyzer was used to measure photosynthetic active radiation (PAR), net photosynthetic rate (A), stomatal conductance (g s) and transpiration rate (E) at CO2 concentrations of 360 μmol mol−1 and ambient humidity and temperature. A, E and g s varied between species, being highest in eucalyptus hybrid GC 15 (24.6 μmol m−2 s−1) compared to eucalyptus hybrid GC 584 (21.0 μmol m−2 s−1), E. grandis (19.2 μmol m−2 s−1), C. africana (17.7 μmol m−2 s−1) and G. robusta (11.1 μmol m−2 s−1). C. africana exhibited high E values (7.0 mmol m−2 s−1) at optimal soil moisture contents than G. robusta (3.9 mmol m−2 s−1) and eucalyptus (5.3 mmol m−2 s−1) in field experiment and G. robusta (3.2 mmol m−2 s−1) and eucalyptus (4.2 mmol m−2 s−1) in pot-grown trees. At very low soil moisture content, extremely small g s values were recorded in GC 15 and E. grandis (8 mmol m−2 s−1) and G. robusta (14 mmol m−2 s−1) compared to GC 584 (46.9 mmol m−2 s−1) and C. africana (90.0 mmol m−2 s−1) indicating strong stomatal control by the species. Instantaneous water use efficiency ranged between 3 and 5 μmol mmol−1 and generally decreased with decline in soil moisture in pot-grown trees but increased with declining soil moisture in field-grown trees.  相似文献   

12.
Zusammenfassung Einige der wichtigsten gegenwärtigen Probleme hinsichtlich der landwirtschaftlichen Schädlinge in Finnland sind folgende:Bei Getreide die Schäden durchCalligypona pellucida am Hafer sowie die Schäden durch die Fritfliege(Oscinella frit) an Saat von Winter- und Sommergetreide, die durch Blasenfüßer(Thysanoptera) u. a. Arten verursachte Weißährigkeit und Schmachtkörnigkeit, deren Bekämpfung noch nicht befriedigend entschieden ist. — Beim RotkleePhytonomus nigrirostris, Apion apricans undA. assimile, Sitona spp. undDitylenchus dipsaci, deren Biologie und Bekämpfung weiterhin fortgesetzt werden, — Bei ÖlpflanzenCeuthorrhynchus assimilis undC. quadridens sowieDasyneura brassicae, deren Bekä mpfung zu ermitteln ist. — Bei Zuckerrübe sowie einigen anderen Kulturpflanzen Bedeutung und Bekä mpfung vonLygus-Arten (besondersL. rugulipennis undL. pratensis). Bekämpfung der Rübenfliege(Pegomyia hyoscyami) bei Zuckerrübenkulturen. — Bei den Wurzelschädlingen von Gemüse und Hackfrüchten Klären von Biologie und Bekämpfung der Kohlfliegen (Hylemyia brassicae undH. floralis), der Fliegenschädlinge von Zwiebeln (Hylemyia antiqua, Eumerus tuberculatus undE. strigatus) und der Möhrenfliege. — Die Wirkung der Spritzungen in Obstgärten auf die wichtigsten Schä dlinge(Metatetranychus pilosus, Doralina pomi, Psylla mali, Carpocapsa pomonella, Argyresthia conjugella) und ihre wirksamsten Feinde.— In Beerengärten bei den ArtenTarsonemus fragariae, Eriophyes ribis undPachynematus pumilio sowie in Obstgärten bei der ArtAnisandrus dispar Intensivierung der Bekä mpfung. — Älchen(Anguillulidae), besondersdas Kleeälchen und Klärung von Lebensbedingungen und Bekämpfung desKartoffelälchens. — Bedeutung und Bekämpfung der Wühlmäuse (besondersMicrotus agrestis, M. arvalis undArvicola terrestris). — Untersuchung der Bedeutung von virusverbreitenden Insektenarten. — Erforschung der Nachteile von Bekämpfungsmitteln für die Pflanzen.  相似文献   

13.
重庆酸雨区缙云山典型林分冠层酸雨淋洗特征   总被引:2,自引:1,他引:2       下载免费PDF全文
选取重庆缙云山的针阔混交林、常绿阔叶林、毛竹林、灌木林4种典型林分,观测酸性降水过程中林外雨、穿透雨及干流等林内水分转换分量中的主要离子含量变化,分析林分冠层对雨水化学组成的影响,结果表明:(1)降雨中的离子当量浓度大小依次是SO42->Ca2+> NH4+>Mg2+>K+>Na+>NO3-;(2)降雨经过林冠层后pH值降低,干流的酸化程度增加最大;(3)降雨经林冠层后离子浓度明显增加(除灌木林),穿透雨中通量增加最大的阴离子和阳离子分别为SO42-(2.19×103~6.47×103 eq·hm-2)和Ca2+(1.41×103~3.39×103 eq-hm-2),离子来源主要为大气沉降和植物分泌物或淋出;(4)同一离子在不同林分的干流和穿透雨中的通量变化不同,反映出不同林分冠层的离子交换性差异.在针阔混交林中,林下降雨净淋溶量大小顺序为SO42->Ca2+> NO3->K+>NH4+>Mg2+> Na+;常绿阔叶林为SO42-> Ca2+> K+>NO3-> NH4+> Mg2+ >Na+;毛竹林为Ca2+> SO42-> K+>NO3-> NH4+>Na+>Mg2+;灌木林为Ca2+> NO3-> K+> Na+>Mg2+> NH4+> SO42-.  相似文献   

14.
广州市酸雨对不同森林冠层淋溶规律的研究   总被引:20,自引:2,他引:20       下载免费PDF全文
1998年4月至1999年3月对广州市白云山马尾松林和常绿阔叶林、广州市龙眼洞马尾松林两试验点进行了酸雨的监测,并测定和分析了林内穿透雨物理量及化学量,旨在探讨酸雨对不同森林冠层养分淋溶规律的影响。结果表明:(1)广州市酸雨占次数的79.7%或占降雨量的95.1%。(2)酸雨通过林冠层后,pH值明显增加。(3)在马尾松林和常绿阔叶林中,某些单次降雨出现SO4^2-、NO3^-、NH4^+Al^3+、Na^+的负淋溶现象,说明森林对这些离子(特别是NO3^-、Aa^3+)具有吸收作用;阔叶林全年的NO3^-和Al^3+净淋溶为负值,说明阔叶林比马尾松林对这两种离子具有更强的吸收能力。(4)雨水酸度增加(即pH值减小),明显提高阳离子Ca^2+、Mg^2+、K^+和Na^+冠层淋溶面分率。(5)NH4^+、SO4^  相似文献   

15.
A typhoon event catastrophically destroyed a 45-year-old Japanese larch plantation in southern Hokkaido, northern Japan in September 2004, and about 90% of trees were blown down. Vegetation was measured to investigate its regeneration process and CO2 flux, or net ecosystem production (NEP), was measured in 2006–2008 using an automated chamber system to investigate the effects of typhoon disturbance on the ecosystem carbon balance. Annual maximum aboveground biomass (AGB) increased from 2.7 Mg ha−1 in 2006 to 4.0 Mg ha−1 in 2007, whereas no change occurred in annual maximum leaf area index (LAI), which was 3.7 m2 m−2 in 2006 and 3.9 m2 m−2 in 2007. Red raspberry (Rubus idaeus) had become dominant within 2 years after the typhoon disturbance, and came to account for about 60% and 50% of AGB and LAI, respectively. In comparison with CO2 fluxes measured by the eddy covariance technique in 2001–2003, for 4.5 months during the growing season, the sum of gross primary production (GPP) decreased on average by 739 gC m−2 (64%) after the disturbance, whereas ecosystem respiration (RE) decreased by 501 gC m−2 (51%). As a result, NEP decreased from 159 ± 57 gC m−2 to −80 ± 30 gC m−2, which shows that the ecosystem shifted from a carbon sink to a source. Seasonal variation in RE was strongly correlated to soil temperature. The interannual variation in the seasonal trend of RE was small. Light-saturated GPP (Pmax) decreased from 30–45 μmol m−2 s−1 to 8–12 μmol m−2 s−1 during the summer season through the disturbance because of large reduction in LAI.  相似文献   

16.
Dissolved inorganic nitrogen (DIN) (as ammonium nitrate) was applied monthly onto the forest floor of one old-growth forest (>400 years old, at levels of 50, 100 and 150 kg N ha−1 yr−1) and two young forests (both about 70 years old, at levels of 50 and 100 kg N ha−1 yr−1) over 3 years (2004–2006), to investigate how nitrogen (N) input influenced N leaching output, and if there were differences in N retention between the old-growth and the young forests in the subtropical monsoon region of southern China. The ambient throughfall inputs were 23–27 kg N ha−1 yr−1 in the young forests and 29–35 kg N ha−1 yr−1 in the old-growth forest. In the control plots without experimental N addition, a net N retention was observed in the young forests (on average 6–11 kg N ha−1 yr−1), but a net N loss occurred in the old-growth forest (−13 kg N ha−1 yr−1). Experimental N addition immediately increased DIN leaching in all three forests, with 25–66% of added N leached over the 3-year experiment. At the lowest level of N addition (50 kg N ha−1 yr−1), the percentage N loss was higher in the old-growth forest (66% of added N) than in the two young forests (38% and 26%). However, at higher levels of N addition (100 and 150 kg N ha−1 yr−1), the old-growth forest exhibited similar N losses (25–43%) to those in the young forests (28–43%). These results indicate that N retention is largely determined by the forest successional stages and the levels of N addition. Compared to most temperate forests studied in Europe and North America, N leaching loss in these seasonal monsoon subtropical forests occurred mainly in the rainy growing season, with measured N loss in leaching substantially higher under both ambient deposition and experimental N additions.  相似文献   

17.
Five new ursane-type triterpenoidal saponins (15), together with five known ones (610), were isolated from the EtOH extract of the roots of Ilex cornuta. The structures of saponins 15 were elucidated as 19α-hydroxyurs-12-en-28-oic acid 3β-O-β-D-glucuronopyranoside (1), 19α-hydroxyurs-12-en-28-oic acid 3β-O-β-D-glucuronopyranoside-6-O-ethyl ester (2), 19α-hydroxyurs-12-en-28-oic acid 3β-O-α-L-arabinopyranosyl-(1  2)-β-D-glucuronopyranoside (3), 3β-O-[α-L-arabinopyranosyl-(1  2)-β-D-glucuronopyranosyl]-19α-hydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (4) and 3β-O-[α-L-arabinopyranosyl-(1  2)-β-D-glucuronopyranoside-6-O-methyl ester]-19α-hydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (5), on the basis of spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR) and chemical reactions. Protective effects of compounds 110 against H2O2-induced H9c2 cardiomyocyte injury were tested. Compounds 15, 7, and 10 showed cell-protective effects. Among them compound 5 exhibited the highest activity. No significant DPPH radical scavenging activity was observed for compounds 110.  相似文献   

18.
A new canker disease of Salix alba and Populus alba has been observed in Xinjiang, China. Black circular spots on dead branches and stems are the symptoms of the disease. Sixty‐seven isolates recovered from Salix matsudana, S. alba and Populus alba were identified as Cryptosphaeria pullmanensis based on morphological features and multigene phylogeny. Pathogenicity tests were performed on S. alba and P. alba stems using the C. pullmanensis isolates. Cankers on and Cryptosphaeria pullmanensis of C. pullmanensis from the stems fulfilled Koch's postulates and confirmed C. pullmanensis as the causal agent of the canker disease. C. pullmanensis is characterized by its yellow stromatic tissue surrounded by a black conceptacle with regularly arranged multiple locules sharing common walls and hyaline, allantoid, aseptate conidia (mean size 7.42 × 1.72 μm). This is the first report of C. pullmanensis causing Cryptosphaeria canker in China, and S. alba and P. alba are new host records for C. pullmanensis.  相似文献   

19.
This study was conducted to determine carbon (C) dynamics following forest tending works (FTW) which are one of the most important forest management activities conducted by Korean forest police and managers. We measured organic C storage (above- and below-ground biomass C, forest floor C, and soil C at 50 cm depth), soil environmental factors (soil CO2 efflux, soil temperature, soil water content, soil pH, and soil organic C concentration), and organic C input and output (litterfall and litter decomposition rates) for one year in FTW and non-FTW (control) stands of approximately 40-year-old red pine (Pinus densiflora S. et Z.) forests in the Hwangmaesan Soopkakkugi model forest in Sancheonggun, Gyeongsangnam-do, Korea. This forest was thinned in 2005 as a representative FTW practice. The total C stored in tree biomass was significantly lower (P < 0.05) in the FTW stand (40.17 Mg C ha−1) than in the control stand (64.52 Mg C ha−1). However, C storage of forest floor and soil layers measured at four different depths was not changed by FTW, except for that at the surface soil depth (0–10 cm). The organic C input due to litterfall and output due to needle litter decomposition were both significantly lower in the FTW stand than in the control stand (2.02 Mg C ha−1 year−1 vs. 2.80 Mg C ha−1 year−1 and 308 g C kg−1 year−1 vs. 364 g C kg−1 year−1, respectively, both P < 0.05). Soil environmental factors were significantly affected (P < 0.05) by FTW, except for soil CO2 efflux rates and organic C concentration at soil depth of 0–20 cm. The mean annual soil CO2 efflux rates were the same in the FTW (0.24 g CO2 m−2 h−1) and control (0.24 g CO2 m−2 h−1) stands despite monthly variations of soil CO2 efflux over the one-year study period. The mean soil organic C concentration at a soil depth of 0–20 cm was lower in the FTW stand (81.3 g kg−1) than in the control stand (86.4 g kg−1) but the difference was not significant (P > 0.05). In contrast, the mean soil temperature was significantly higher, the mean soil water content was significantly lower, and the soil pH was significantly higher in the FTW stand than in the control stand (10.34 °C vs. 8.98 °C, 48.2% vs. 56.4%, and pH 4.83 vs. pH 4.60, respectively, all P < 0.05). These results indicated that FTW can influence tree biomass C dynamics, organic C input and output, and soil environmental factors such as soil temperature, soil water content and soil pH, while soil C dynamics such as soil CO2 efflux rates and soil organic C concentration were little affected by FTW in a red pine stand.  相似文献   

20.
Summary The present paper reports on an outbreak of the False Pine Webworm (Acantholyda erythrocephala L.) in the Steinfeld of Lower Austria, from its detection in July 1964 up to swarming of wasps in April 1967. The course of gradation and resulting damages are described, and data obtained on development, manner of life, and mortality given. In plantations of predominant Austrian Black Pine (Pinus nigra ssp.austriaca) and Scots Pine(Pinus silvestris) the former, too, was attacked though to a considerably lesser extent than the latter. Among mortality factors observed, most important was a nuclear polyhedrosis, which, during the first year of outbreak, killed numerous pseudocaterpillars, but sensibly diminished in lethal effect in the further course of calamity. In connection with the outbreak ofAcantholyda erythrocephala, some other pest occurrences in the plantations are mentioned. A possible competition effect of a previous outbreak ofNeodiprion sertifer, lasting several years, and one ofDendrolimus pini L., lasting two years, resulting in inhibitions of a more precocious development of the outbreak ofAcantholyda erythrocephala, and in prevention of a nascent gradation ofPanolis flammea by the multiplication ofAcantholyda taking its course, is particularly referred to. Control experiments were done with the fumigant “Kerfex-Nebelk?rper/rd. An effective control by this product, too, must be carried out soon after emerging of young larvae.
Résumé Le présent mémoire rend compte d'une pullulation de la Lyde bleue du Pin (Acantholyda erythrocephala L.) au Steinfeld en Basse-Autriché, à partir de sa découverte au mois de Juillet 1964 jusqu'à l'essaimage des guépes au mois d'Avril 1967. Le cours de la gradation et ses effets nuisibles sont caracté risés avec des données obtenues sur le développement, la manière de vivre et la mortalité de l'insecte. Dans les plantations où dominaient le Pin noir d'Autriche (Pinus nigra ssp.austriaca) et le Pin sylvestre(Pinus silvestris), le Pin noir a aussi été attaqué, mais à un bien moindre degré que le Pin sylvestre. Parmi les facteurs relevés de mortalité le plus important a été une maladie cubique nucléaire, faisant dépérir de nombreuses fausses chenilles pendant la première année de la calamité, mais ne déployant que peu d'activité pernicieuse au cours ultérieur de la gradation. En rapport avec cette gradation deAcantholyda erythrocephala on mentionne quelques autres apparitions d'insectes nuisibles dans les plantations. On met spécialement en relief des effets possibles de compétition de la part d'une précédente calamité de plusieurs années deNeodiprion sertifer et d'une autre, de deux années, deDendrolimus pini L., par rapport à un ralentissement du développement de l'attaque massive del'Acantholyda erythrocephala et à l'empéchement d'une gradation naissante dePanolis flammea par ie déroulement de la gradation deAcantholyda. Des essais de lutte ont été entrepris avec le fumigant ?Kerfex-Nebelk?rper?. Si la lutte doit être efficace, il faut l'exécuter peu de temps après l'eclosion finie des jeunes larves.

Резюме Настоящая статья доносит о массовом размножении красноголового общественного пилильщика — ткача,Acatholyda erythrocephala L., в Штейнфельде (Нижняя Австрия), от его открытия в июле 1964г. до роения ос в апреле 1967г. Характеризуются ход градащии и вредные действия так как приводятся информации о развитии, способе жизни и смертности. В культурах, составленных преимущестнно из сосен австрийской (Pinus nigra ssp. austriaca) и обыкновенной (P. silvestris) была поражена и австрийская, хотя в значительно менышей степени, чем обыкновенная. Среди действующих факторов смертиности была важнейшим ядерная полиэдровая болезнь, которая убила в первом году бедствия многочисленных лжегусениц, а в далышем ходу показывала уже мало смертного действия. В связи с градацииAcantholyda erythrocephala упомнаются и другие появления вредителей в культурах. Указывается особенно на возможные конкуренцийные действия предшествующей долголетной градацииNeodiprion sertifer и двухлетной таковойDendrolimus pini L. по отношению к торможениям более ранного развития массового появленияAcontholyda erythrocephala и препятствованию возникающей градацииPanolis flammea протекающим размножением акантолиды. Попытки борьбы были установлены фумигантом ?Керфекс -Небелькерпер?. Борьбу, если должна быть успешной, нужно проводить и этим средством скоро после вылупляния молодых личинок.


Die vorliegenden Beobachtungen der derzeit noch weiter laufenden Kalamit?t schlie?en mit der Flugperiode 1967 ab. Von H. Schmutzenhofer werden bzw. wurden weitere Untersuchungen zum Auftreten dieses Sch? dlings besonders zur Erlangung kritischer Ei- und Larvenzahlen, zur Kl?rung des Problems des überliegens und Auffindung wirksamer Bek?mpfungsmittel durchgeführt.  相似文献   

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