Suchergebnisse

The Mediterranean basin is recognized as a global biodiversity hotspot accounting for more than 25,000 plant species that represent almost 10% of the world's vascular flora. In particular, the maquis vegetation on Mediterranean islands and archipelagos constitutes an important resource of the Mediterranean plant diversity due to its high rate of endemism. Since 2009, a severe and widespread dieback and mortality of Quercus ilex trees and several other plant species of the Mediterranean maquis has been observed in the National Park of La Maddalena archipelago (northeast Sardinia, Italy). Infected plants showed severe decline symptoms and a significant reduction of natural regeneration. First studies revealed the involvement of the highly invasive wide-host range pathogen Phytophthora cinnamomi and several fungal pathogens. Subsequent detailed research led to a better understanding of these epidemics showing that multiple Phytophthora spp. were involved, some of them unknown to science. In total, nine Phytophthora species were isolated from rhizosphere soil samples collected from around symptomatic trees and shrubs including Asparagus albus, Cistus sp., Juniperus phoenicea, J. oxycedrus, Pistacia lentiscus and Rhamnus alaternus. Based on morphological characters, growth-temperature relations and sequence analysis of the ITS and cox1 gene regions, the isolates were identified as Phytophthora asparagi, P. bilorbang, P. cinnamomi, P. cryptogea, P. gonapodyides, P. melonis, P. syringae and two new Clade 6 taxa which are here described as P. crassamura sp. nov. and P. ornamentata sp. nov. Pathogenicity tests supported their possible involvement in the severe decline that is currently threatening the Mediterranean maquis vegetation in the La Maddalena archipelago. ; National Park of the La Maddalena archipelago; Sardinian Regional Government; Autonomous Region of Sardinia, Visiting Professor Programme at the University of Sassari, Italy ; info:eu-repo/semantics/publishedVersion

Ash dieback has become a continent-wide problem in a relatively short period of time which has generated a significant amount of research within and across countries. To consider what lessons have been learned, this project convened a workshop of researchers and government and non-governmental representatives from 10 EU countries to describe the impact of the disease, research undertaken and underway, and management responses. From the workshop and following work, it was identified that whilst there was much ongoing research which had the potential to deliver long term benefits, a lack of immediately useable information for land managers risks ash being lost from the landscape before long-term research outputs are available for use. The Awareness, Planning, Action and Recovery framework developed with Defra funding (and subsequently published, Stokes and Jones, 2019) was used to explore this issue. Given the research backgrounds of the attendees there was a strong emphasis on the search for resistant or tolerant species. This line of research, by its nature, is uncertain and long term. There appeared to be a number of potential interesting options but none of them were particularly close to offering a solution to the large-scale loss of ash from the landscape. Outputs of resistance/tolerance research (resistant/tolerant ash) will most likely be available after then period of high impact and mortality of ash dieback has passed. As such, this research may be more pertinent to the post invasion stage of Ash dieback. Land managers may demonstrate low acceptance/uptake of resistant/tolerant ash if they are unsupported during the high mortality phase of ash dieback. In the short term, adopting planting strategies to maintain/increase high genetic diversity may offer more immediate solutions for land managers and may also have a positive effect across multiple threats. Research into more immediate response options (e.g. silviculture) were mentioned. However, there was limited discussion of how the outputs of this ...