At least 10% of the world's tree species are threatened with extinction and pathogens are increasingly implicated in tree threats. Coextinction and threats to affiliates as a consequence of the loss or decline of their host trees is a poorly understood phenomenon. Ash dieback is an emerging infectious disease causing severe dieback of common ash Fraxinus excelsior throughout Europe. We utilized...

The ambrosia beetle, Platypus koryoensis (Murayama), vectors the Korean oak wilt (KOW) pathogen, Raffaelea quercus-mongolicae K.H. Kim, Y.J. Choi, & H.D. Shin, in Korea, which is highly lethal to Mongolian oak, Quercus mongolica Fisch., and is considered a major threat to forest ecosystem health. We characterized the attack pattern of P. koryoensis along the lower trunk of 240 Mongolian oaks i...

During the past decade bark beetle (Ips typographus) attacks killed nearly all of the Norway spruce [Picea abies (L.) Karst.] stands in the unmanaged zone in the highlands of the Bavarian Forest National Park. This study was conducted to predict if and how long the catastrophic event might cause elevated nitrate NO3(-) concentration in seepage water, and if the presence of ground vegetation may...

Dieback and wilting symptoms caused by complex soilborne fungi are nowadays the most serious threatening disease affecting olive trees (Olea europaea) in Tunisia and presumably in many Mediterranean basin countries. Fusarium is one of the important phytopathogenic genera associated with dieback symptoms of olive trees. The objective of the present study was to confirm the pathogenicity of Fusar...

The expanding phenomenon of dieback is caused by the reaction of trees against the harmful biotic and a biotic factor that lead to dying of shoots and branches of trees from upper crown to lower crown. This phenomenon spreads throughout the leaves and branches and all parts of the plant and may finally lead to the death of the plant. This study aimed to identify species dieback especially Carpi...

Since 2001, patches of dying vegetation have been observed in Georgia marshes, generally during periods of dry or drought conditions. These events are collectively referred to as salt marsh dieback. Salt marsh dieback is characterized by the thinning and browning of Spartina alterniflora and other marsh grasses which eventually leads to plant death. This is a concern because salt marsh habitat ...

The phenomenon of patch dieback in stands of Nothofagus on Mt. Giluwe, in the southern highlands of Papua New Guinea, is described. Ecological studies that have been carried out are reviewed. Based upon the results of surveys on Mt. Giluwe, the role of Phytophthora cinnamomi in contributing to the dieback is examined. A comparison is made of Nothofagus dieback on Mt. Giluwe with Metrosideros di...

Since 1991 epidemic dieback of the kelp Ecklonia radiata has been observed at the Leigh h4arine Reserve and other sites in northern New Zealand. As the dominant phaeophycean E. radiata is a very important component of the eastern coastal ecosystem, providing both food and refuge for many species. Examination of the E. radiata sap extracts by electron microscopy detected the presence of both str...

Background: A severe outbreak of Diplodia-associated dieback Pinus radiata D.Don shoots in 1967 prompted a pilot programme selection for resistance to dieback. Plus trees were selected 1970 absence dieback, growth and tree form, seed collected. Methods: Twenty open-pollinated progenies plus two control lots field-tested on sites, assessed around 6.5 years after planting. Alternative measures sh...