Mari Mette Tollefsrud
Research Scientist
(+47) 907 60 870
mari.mette.tollefsrud@nibio.no
Place
Ås H8
Visiting address
Høgskoleveien 8, 1433 Ås
Authors
Fride Høistad Schei Mie Prik Arnberg John-Arvid Grytnes Maren Stien Johansen Jørund Johansen Anna Birgitte Milford Anders Røynstrand Mari Mette TollefsrudAbstract
Climate change and human activities have accelerated the spread of non-native species, including forest pests and pathogens, significantly contributing to global biodiversity loss. Pathogens pose a significant threat to forest ecosystems due to a lack of coevolution with native hosts, resulting in ineffective defence mechanisms and severe consequences for the affected tree species. Ash dieback, caused by the fungus Hymenoscyphus fraxineus, is a relatively new invasive forest pathogen threatening ash (Fraxinus excelsior) with mortality rates in northern Europe reaching up to 80 %. The loss of ash due to dieback has severe ecological implications, potentially leading to an extinction cascade as ash provides crucial habitats and resources for many organisms. Despite this, the consequences of ash dieback on associated communities are largely unknown. To address this, we analysed changes in species richness, vegetation structure, and composition in 82 permanent vegetation plots across 23 Norwegian woodlands. We compared data collected before and 10–14 years after the emergence of ash dieback. In these woodlands, ash significantly declined in cover, leading to changes in tree species composition and facilitating the establishment of other woody tree species like hazel (Corylus avellana) and the invasive species sycamore (Acer pseudoplatanus). Despite these changes in the tree species composition, no significant alterations were observed in the understory plant community, indicating a degree of ecosystem resilience or a lagging community response. At this point, and with our focus on the vascular plants, we do not find support for cascading effects due to ash dieback. However, our findings demonstrate that one invasive species is facilitating the expansion of another, raising concerns about potential ecological imbalance and cascading effects in the future.
Authors
Jennifer James Chedly Kastally Katharina B. Budde Santiago C. González-Martínez Pascal Milesi Tanja Pyhäjärvi Martin Lascoux Paraskevi Alizoti Ricardo Alía Olivier Ambrosio Filippos A Aravanopoulos Georg Von Arx Albet Audrey Francisco Auñón Camilla Avanzi Evangelia Avramidou Francesca Bagnoli Marko Bajc Eduardo Ballesteros Evangelos Barbas José M García Del Barrio Cristina C Bastias Catherine Bastien Giorgia Beffa Raquel Benavides Vanina Benoit Frédéric Bernier Henri Bignalet Guillaume Bodineau Damien Bouic Sabine Brodbeck William Brunetto Jurata Buchovska Corinne Buret Melanie Buy Ana M Cabanillas-Saldaña Bárbara Carvalho Stephen Cavers Fernando Del Caño Sandra Cervantes Nicolas Cheval José M Climent Marianne Correard Eva Cremer Darius Danusevičius Benjamin Dauphin Jean-Luc Denou Bernard Dokhelar Alexis Ducousso Bruno Fady Patricia Faivre-Rampant Anna-Maria Farsakoglou Patrick Fonti Ioannis Ganopoulos Olivier Gilg Nicolas De Girardi René Graf Alan Gray Delphine Grivet Felix Gugerli Christoph Hartleitner Katrin Heer Enja Hollenbach Agathe Hurel Bernard Issenhuth Florence Jean Véronique Jorge Arnaud Jouineau Jan-Philipp Kappner Robert Kesälahti Florian Knutzen Sonja T Kujala Timo A Kumpula Katri Kärkkäinen Mariaceleste Labriola Celine Lalanne Johannes Lambertz Gregoire Le-Provost Vincent Lejeune Isabelle Lesur-Kupin Joseph Levillain Mirko Liesebach David López-Quiroga Ermioni Malliarou Jérémy Marchon Nicolas Mariotte Antonio Mas Silvia Matesanz Benjamin Meier Helge Meischner Célia Michotey Sandro Morganti Tor Myking Daniel Nievergelt Anne Eskild Nilsen Eduardo Notivol Dario Isidro Ojeda Alayon Sanna Olsson Lars Opgenoorth Geir Østreng Birte Pakull Annika Perry Sara Pinosio Andrea Piotti Christophe Plomion Nicolas Poinot Mehdi Pringarbe Luc Puzos Annie Raffin José A Ramírez-Valiente Christian Rellstab Dourthe Remi Oliver Reutimann Sebastian Richter Juan J Robledo-Arnuncio Odile Rogier Elisabet Martínez Sancho Outi Savolainen Simone Scalabrin Volker Schneck Silvio Schueler Ivan Scotti Sergio San Segundo Vladimir Semerikov Lenka Slámová Ilaria Spanu Jørn Henrik Sønstebø Jean Thevenet Mari Mette Tollefsrud Norbert Turion Fernando Valladares Giovanni G. Vendramin Marc Villar Marjana Westergren Johan WestinAbstract
New mutations provide the raw material for evolution and adaptation. The distribution of fitness effects (DFE) describes the spectrum of effects of new mutations that can occur along a genome, and is, therefore, of vital interest in evolutionary biology. Recent work has uncovered striking similarities in the DFE between closely related species, prompting us to ask whether there is variation in the DFE among populations of the same species, or among species with different degrees of divergence, that is whether there is variation in the DFE at different levels of evolution. Using exome capture data from six tree species sampled across Europe we characterized the DFE for multiple species, and for each species, multiple populations, and investigated the factors potentially influencing the DFE, such as demography, population divergence, and genetic background. We find statistical support for the presence of variation in the DFE at the species level, even among relatively closely related species. However, we find very little difference at the population level, suggesting that differences in the DFE are primarily driven by deep features of species biology, and those evolutionarily recent events, such as demographic changes and local adaptation, have little impact.