Hylesinus piniperda und Hyl. minor in der Fichte

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Der Einfluß der Siedlungsdichte und anderer Faktoren auf die Anzahl der Nachkommen vonBlastophagus piniperda L.

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Das Berhalten der Fichte auf aufgeforfteten Feldern

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Die freie Pirch auf dem Boofer Hart bei Memmingen

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Die Sommerkrise der Erdmaus (Microtus agrestis L.) Teil I. Die Entwicklung einer freilebenden Population

An analysis of the seasonal cycle of growth and reproduction of the field vole in southern Bavaria in the years 1972, 74 and 75 showed a turnover of development in midsummer indicated by reduced weight increase, restricted reproduction and low fertility. Highest weight increase of 436 marked and recaptured specimens in the field was observed during May and June with 269 mg (335 mg males, 188 mg females) per day and individual (Abb. 1). During August and September a mean weight decrease of –82 mg per animal was measured. The daily weight increase per individual reached 67 mg (74 mg males, 54 mg females) in the average of all observed years.An autopsy of 220 snap-trapped specimens showed a significantly reduced weight of testes (–86%), of stomach content (–22%) and of liver (–18%) in late summer compared to the weight in spring when growth and reproduction were highest and these organ weights reached the maximum level. In the summer crisis also some blood parameters showed significant changes. The erythrocyte counts were reduced by –34% hemoglobin content by –24%, hematocrit by –7%, glucose concentration by –80% and lipid content by –33% in comparison to the mean values observed in December and January when these parameters reached the maximum level. However the spleen size was increased by 140% and the leucocyte counts were augmented by 234% in late summer.A complex of factors influencing the summer crisis of the field vole such as detioration of food supply, increased parasite attack especially of Babesiosis and hormonal changes of growth potencie during the seasonal cycle of development were discussed.

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Ersatz- bezw. Adventiv-Wurzlbildung dei der Fichte

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Die Freie Durchforstung auf der Geislinger Forstversammlung

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纵坑切梢小蠹危险性分析

本文参照国际有害生物危险性分析(Pest Risk Analysis)方法,从纵坑切梢小蠹的国内外分布状况、潜在 危险性、寄主植物的经济重要性、传播蔓延的可能性以及危险性的管理难度等5个方面进行了定性、定量分 析,对纵坑切梢小蠹的危险性作出了综合评价,认为纵坑切梢小蠢在我国属于中度危险的有害生物。     

两种切梢小蠹生态学特性比较研究

纵坑切梢小蠹和横坑切梢小蠹是中国主要的森林蛀干害虫。在云南,两虫经常在云南松等松类树种上共同危害,造成重大生态和经济损失。这两种小蠹的种群结构因地区而异,其性比、成虫在枝梢上聚集危害的时间及其在树冠上的空间分布规律基本相同,但在树干上的空间分布规律有很大差异。通过研究并比较这两种小蠹的种群结构、性比、季节分布及空间分布等生态学特性差异,对防治有重要意义。     

Die Nutzholzerziehung der Kiefer mit Hilfe der Weymoutskiefer auf Buntsandstein

European Journal of Forest Research -     

Die Freie Durchsorstung auf der Eeislinger Forstversammlung

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