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Research with regard to forest protection started in the 19th century and is a relatively young field when compared to the long and diverse history of the human use of forests. However, since then there has been significant progress and development in the field of forest protection research. This article provides an overview on this development in Germany, starting from the mainly descriptive research in the beginning, followed by the subsequent development of control measures up to the large challenges of climate change and globalisation. The article does not claim to be complete and focuses on forest entomology and forest pathology. The overview is accompanied by a systematic analysis of publications on forest protection research in the Journal für Kulturpflanzen. Moreover, a short outlook on the future of forest protection research is provided. [ABSTRACT FROM AUTHOR]

In recent years collar necroses and butt rot associated with the ash dieback disease occurred with alarming frequency in Fraxinus excelsior. We analysed tree ring structures to identify the year of necrosis initiation on a set of 507 necroses on 155 stem discs from nine severely diseased south-western German stands. The number of first-time infections of trees was highest from 2010 to 2012 and slightly decreased in 2013 and 2014, whereas the total number of newly emerging individual necroses remained high. Logistic modelling of dis- ease progression suggests that collar rot infection has almost reached its maximum incidence and that a fraction of trees will remain healthy at the root collar. On average, Hymenoscyphus fraxineus was isolated more frequently from younger collar necroses, whereas older necroses were more often colonized by Armillaria spp. Advanced stages of rot that may pose a risk to forest workers, visitors and traffic were observed already in two years-old necroses infected by Armillaria spp. [ABSTRACT FROM AUTHOR]

Cryptostroma corticale (Ellis & Everh.) P.H. Greg. & S. Waller, the causal agent of sooty bark disease, has led to the death of sycamore (Acer pseudoplatanus L.) in many regions in Germany and other European countries in the recent years, especially supported by dry and hot summers. As a result, there is an urgent need for further scientific research on this pathogen in order to develop sustainable strategies for the protection of sycamore. The fungus belongs to the ascomycetes and is classified in the genus Biscogniauxia Kuntze due to its genetic similarities. Unlike the other Biscogniauxia species, C. corticale is not known to have a teleomorphic fruiting body, despite a relatively diverse population structure has been demonstrated by somatic compatibility experiments. For these reasons, it is unlikely that C. corticale does not form a teleomorphic fruiting body. More likely, it can be assumed that it exists a teleomorphic fruiting body of C. corticale, but it has not yet been recognized as such. Therefore, it is possible that the teleomorph, for which it is searched, is not yet described or it could be found in the already described but not yet sequenced species of the genus Biscogniauxia. In the current project, as many different cultures (mainly from material collected in Germany) and fungarium specimens (from around the world) as possible from the genus Biscogniauxia will be collected and gathered. Subsequently they will be evaluated and analyzed morphologically and phylogenetically with different marker genes. First phylogenetic results with the marker gene region ITS confirm the partly high genetic similarity of C. corticale to the genus Biscogniauxia. However, a teleomorphic Biscogniauxia species that can be genetically assigned with certainty to the anamorphic species C. corticale has not yet been found. Furthermore, it appears that the previous taxonomic classification of some Biscogniauxia species is not conclusive in itself. The further acquisition of marker sequences is necessary to further search for the teleomorphic fruiting body of C. corticale, as well as to perform a comprehensive phylogenetic analysis and to contribute to fungal DNA-barcoding. [ABSTRACT FROM AUTHOR]

European ash ( Fraxinus excelsior) is threatened by Hymenoscyphus pseudoalbidus, the agent of ash dieback disease. Beside ordinary ash dieback symptoms, collar rots have been reported on declining ashes as an additional problem of increasing severity. Since 2009, ash dieback has been surveyed annually in a provenance trial on four different sites in southwest Germany (Metzler et al. in Ger J For Res 183:168–180, 2012 ). The trial was established in 2005. Data of tree growth, ash dieback symptoms and collar rot prevalence were collected by surveying the trial in summer 2012 and compared with previously published data of the trial. Evaluations revealed a continuous and considerable increase in dieback severity since 2009. The results suggest that the infection process has not come to a standstill yet. Up to 2012, 6 % of the trees remained symptomless, whereas mortality added up to 9 %. There were significant differences in ash dieback severity between the investigated provenances. Collar rot prevalence ranged from 19 to 59 % between study sites. Moreover, high spatial dependency of collar rot prevalence could be detected within sites. Collar rots were more abundant on trees of severe ash dieback intensity, but could also be detected on 15 % of otherwise healthy trees. Mycelium from collar rots could be identified by means of RFLP analyses and sequencing of the ITS region as most likely belonging to Armillaria gallica. The possible roles of Armillaria spp. and H. pseudoalbidus in collar rot formation are discussed. [ABSTRACT FROM AUTHOR]

European ash ( Fraxinus excelsior) is threatened by Hymenoscyphus pseudoalbidus, the agent of ash dieback disease. Beside ordinary ash dieback symptoms, collar rots have been reported on declining ashes as an additional problem of increasing severity. Since 2009, ash dieback has been surveyed annually in a provenance trial on four different sites in southwest Germany (Metzler et al. in Ger J For Res 183:168–180, 2012 ). The trial was established in 2005. Data of tree growth, ash dieback symptoms and collar rot prevalence were collected by surveying the trial in summer 2012 and compared with previously published data of the trial. Evaluations revealed a continuous and considerable increase in dieback severity since 2009. The results suggest that the infection process has not come to a standstill yet. Up to 2012, 6 % of the trees remained symptomless, whereas mortality added up to 9 %. There were significant differences in ash dieback severity between the investigated provenances. Collar rot prevalence ranged from 19 to 59 % between study sites. Moreover, high spatial dependency of collar rot prevalence could be detected within sites. Collar rots were more abundant on trees of severe ash dieback intensity, but could also be detected on 15 % of otherwise healthy trees. Mycelium from collar rots could be identified by means of RFLP analyses and sequencing of the ITS region as most likely belonging to Armillaria gallica. The possible roles of Armillaria spp. and H. pseudoalbidus in collar rot formation are discussed. [ABSTRACT FROM AUTHOR]