Bjelke, Ulf
- SLU Artdatabanken, Sveriges lantbruksuniversitet
Översiktsartikel2016Vetenskapligt granskadÖppen tillgång
Dieback of riparian alder caused by the Phytophthora alni complex: projected consequences for stream ecosystems
Bjelke, Ulf; Boberg, Johanna; Tattersdill, Kristina; Mckie, Brendan; Oliva Palau, Jonàs
Sammanfattning
1. Alder trees (Alnus spp.) are key nitrogen-fixing riparian species in the northern hemisphere. Inputs of nitrogen-rich leaf litter from alder into stream food webs can contribute significantly to nitrogen dynamics at local and landscape scales. Alder trees also provide habitats for terrestrial and aquatic organisms, and help stabilize river banks.
2. Recently, substantial declines in alder stands have occurred along streams in Europe, with damages observed in some parts of North America also. A major driver has been the invasive oomycete pathogen Phytophthora alni species complex, which can spread rapidly along stream networks.
3. This review synthesises information on the pathogen, processes of spread and infection, and its impacts on alder. We further address the potential ecosystem-level and management consequences of the decline of alder, and highlight research needs.
4. The alder dieback caused by P. alni is associated with reductions in shade and quality and quantity of leaf litter. A decline in the structural integrity of branches and roots further threatens bank stability. Stream banks dominated by other tree species or no trees at all will result in ecosystem-level changes both above and below the waterline.
5. The P. alni taxonomic complex includes different species with varying phenotypes. An improved understanding of their environmental tolerances, virulence and evolution, along with the processes regulating the spread and impacts of the pathogen, would assist in identification of the riparian and stream systems most vulnerable not only to invasion but also to the heaviest disease outbreaks and ecosystem-level impacts.
6. Within the P. alni complex, the highly pathogenic hybrid species P. x alni is favoured by mild winters and warm, but not excessively hot summer temperatures suggesting possible changes in distribution and level of impact under future global climate change.
Nyckelord
ecosystem change; invasive species; pathogens; riparian communities; running waters
Publicerad i
Freshwater Biology
2016, volym: 61, nummer: 5, sidor: 565-579
SLU författare
Boberg, Johanna
- Institutionen för skoglig mykologi och växtpatologi, Sveriges lantbruksuniversitet
- Institutionen för skoglig mykologi och växtpatologi, Sveriges lantbruksuniversitet
Tattersdill, Kristina
- Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
- Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
Mckie, Brendan
- Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
- Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
Oliva Palau, Jonàs
- Institutionen för skoglig mykologi och växtpatologi, Sveriges lantbruksuniversitet
- Institutionen för skoglig mykologi och växtpatologi, Sveriges lantbruksuniversitet
Associerade SLU-program
SLU Future Forests
SLU Nätverk växtskydd
Globala målen (SDG)
SDG15 Ekosystem och biologisk mångfald
UKÄ forskningsämne
Mikrobiologi
Fisk- och akvakulturforskning
Ekologi
Publikationens identifierare
- DOI: https://doi.org/10.1111/fwb.12729
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/73773