Symbioses: Plant, Animal, and Microbe Interactions
Walker, Jennifer KM , Ward, Valerie , Twieg, Brendan , Jones, Melanie D .
Analysis of the community structure of ectomycorrhizal root tips in coarse woody debris retention and removal plots at a high elevation spruce forest reveals a surprising member.
Shifts in ectomycorrhizal fungal (EMF) community composition occur after clearcut logging, resulting in the loss of some forest species. Decayed wood is a remnant of the original forest and an important habitat for particular EMF species. Therefore, retention of coarse woody debris (CWD) at harvest is expected to contribute to the long-term preservation of pre-harvest community structure because as it decays, niches for EMF will be maintained.
In order to assess if leaving CWD after clearcutting has a medium-term effect on the EMF community, we examined ectomycorrhizal root tips in CWD retention and CWD removal plots at a high elevation spruce forest 12 years after harvest. Two 1 ha treatment plots are located in each of three replicate 10 ha clearcut blocks. Root tips were sampled from ten 10 yr-old saplings in each treatment plot. The tips were grouped morphologically and identified by sequencing of the ITS region.
Fungal DNA detected included that of Alloclavaria purpurea, whose mycorrhizal status has been suspected but remains unconfirmed. When suspect samples were cloned and sequenced, DNA of other fungal species was not detected. Consequently, although further work is required, we believe that A. purpurea was forming the mycorrhizas.
Thelephora terrestris colonized 17.6% of the root tip community, and dominated at one block. Interestingly, A. purpurea colonized 7.3% of all tips, but was not detected at this block. Analysis of the relative abundance of all taxa detected no significant effect of CWD retention or removal, but there was a significant difference in the relative abundance of taxa between blocks.
We conclude that retention of CWD has not affected the EMF community at the plot scale over the medium term. We are now conducting sampling at a finer scale to determine if ectomycorrhizal communities differ in close proximity to the 12-yr-old logs.
Log in to add this item to your schedule
1 - University of British Columbia Okanagan, Biology and Physical Geography, 3333 University Way, Kelowna BC, V1V 1V7, Canada
coarse woody debris
Presentation Type: Poster:Posters for Topics
Location: Event Tent/Cliff Lodge
Date: Monday, July 27th, 2009
Time: 5:30 PM