Slowed biogeochemical cycling in sub-arctic birch forest linked to reduced mycorrhizal growth and community change after a defoliation event
Parker, Thomas C.
Frey, Serita D.
Wookey, Philip A.
MetadataShow full item record
KeywordDefoliation; Nitrogen; Carbon; Birch forest; Sub-arctic; Ectomycorrhizal fungi; Community change
Sub-arctic birch forests (Betula pubescens Ehrh. ssp. czerepanovii) periodically suffer large-scale defoliation events caused by the caterpillars of the geometrid moths Epirrita autumnata and Operophtera brumata. Despite their obvious influence on ecosystem primary productivity, little is known about how the associated reduction in belowground C allocation affects soil processes. We quantified the soil response following a natural defoliation event in sub-arctic Sweden by measuring soil respiration, nitrogen availability and ectomycorrhizal fungi (EMF) hyphal production and root tip community composition. There was a reduction in soil respiration and an accumulation of soil inorganic N in defoliated plots, symptomatic of a slowdown of soil processes. This coincided with a reduction of EMF hyphal production and a shift in the EMF community to lower autotrophic C-demanding lineages (for example, /russula-lactarius). We show that microbial and nutrient cycling processes shift to a slower, less C-demanding state in response to canopy defoliation. We speculate that, amongst other factors, a reduction in the potential of EMF biomass to immobilise excess mineral nitrogen resulted in its build-up in the soil. These defoliation events are becoming more geographically widespread with climate warming, and could result in a fundamental shift in sub-arctic ecosystem processes and properties. EMF fungi may be important in mediating the response of soil cycles to defoliation and their role merits further investigation.
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosystems 20 (2017): 316–330, doi:10.1007/s10021-016-0026-7.
Suggested CitationArticle: Parker, Thomas C., Sadowsky, Jesse, Dunleavy, Haley, Subke, Jens-Arne, Frey, Serita D., Wookey, Philip A., "Slowed biogeochemical cycling in sub-arctic birch forest linked to reduced mycorrhizal growth and community change after a defoliation event", Ecosystems 20 (2017): 316–330, DOI:10.1007/s10021-016-0026-7, https://hdl.handle.net/1912/8941
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Changes in species abundance after seven years of elevated atmospheric CO2 and warming in a Subarctic birch forest understorey, as modified by rodent and moth outbreaks Svensson, Brita M.; Carlsson, Bengt Å.; Melillo, Jerry M. (PeerJ, 2018-05-29)A seven-year long, two-factorial experiment using elevated temperatures (5 °C) and CO2 (concentration doubled compared to ambient conditions) designed to test the effects of global climate change on plant community composition ...
Short term changes in moisture content drive strong changes in Normalized Difference Vegetation Index and gross primary productivity in four Arctic moss communities May, Jeremy L.; Parker, Thomas C.; Unger, Steven; Oberbauer, Steven F. (2018-04)Climate change is currently altering temperature and precipitation totals and timing in Arctic regions. Moss communities constitute much of the understory in Arctic vegetation, and as poikilohydric plants moss are highly ...
Bacterioplankton community shifts in an Arctic lake correlate with seasonal changes in organic matter source Crump, Byron C.; Kling, George W.; Bahr, Michele; Hobbie, John E. (American Society for Microbiology, 2003-04)Seasonal shifts in bacterioplankton community composition in Toolik Lake, a tundra lake on the North Slope of Alaska, were related to shifts in the source (terrestrial versus phytoplankton) and lability of dissolved organic ...