Teakettle is a beautiful old growth mixed conifer forest in the lower Sierra (~80 km east of Fresno). Four ECM hosts occur commonly across my study sites: Abies concolor, A. magnifica, Pinus lambertiana, and P. jeffreyi. In this forest I have tried to focus in on one host relative to the mature ECM community and two relative to the spore bank.
- ECM community structure around Abies spp
- spore bank spatial structure relative to P. jeffreyi and A. concolor (with Diem Nyguyen)
- understanding ECM relative to the root community, small mammal diet and hypogeous fruiting habit (collaboration with Malcolm North and Marc Meyer at UC Davis, and Jim Trappe at Oregon State U.) (click here for poster presented at ICOM4 August 2003 - 2.9MB in pdf format)
- role of heat in spore bank activity (with Megan Canright)
Izzo, A.D., M. Canright, and T.D. Bruns. Effects of temperature on ectomycorrhizal colonization of Pinus jeffreyi roots by resistant propagules. (in prep)
Izzo, A.D., D. Nguyen and T.D. Bruns. Spatial structure
of a Sierra Nevada ectomycorrhizal spore bank and its relationship to the
community. (in prep)
Izzo, A.D., J. Agbowo, and T.D. Bruns. Detection
of stand-level temporal change in belowground ectomycorrhizal community
structure in an
old-growth mixed-conifer forest. (submitted)
Izzo, A.D., M. Meyer, M. North, J.M. Trappe, and T.D. Bruns. Hypogeous ectomycorrhizal fungal species on roots and in small mammal diet in a mixed conifer forest. (submitted)(ICOM4 poster in pdf format)
North, M, B. Oakley, J. Chen, H. Erickson, A. Gray, A.D. Izzo, D. Johnson, S. Ma, H. Marra, M. Meyer, K. Purcell, B. Roath, R. Rambo, D. Rizzo, T. Schowalter. 2002 Vegetation and ecological characteristics of mixed-conifer and red fir forests at the Teakettle Experimental Forest. PSW Gen Tech Rep 186 (pdf)
Service road through Teakettle
looking up at the Abies spp in a gap
The fruiting fungi....
What you see when you peel back a bump in the thick duff layer - a typical failed attempt for an epigeous sporocarp to bust through but only being able to deposit its spores locally. Hypogeous fungi seem to do very well in this forest which may be a result of these resistant barriers and consistently hot and dry summers.
Post-burn pezizalean fungi in BN plot. Not necessarily ECM but common spring fruiters .
The fungi on the roots....
ECM root tips from UN plot. Note proximity - probably less than 0.5 cm - of the 3 types in the last image. This illustrates how diverse the ECM of this system are and thus the challenges to assessing ECM communities here.
The reactive spores.....
An ECM root tip from bioassay, most likely a Rhizopogon sp. Note the color on this fungus - it ranges from white to a dark purple. Developmental morphotypic variation like this makes molecular approaches more practical at the scale I am working on. Also interesting to note is how much cleaner roots from bioassays are.
The dispersable spores....
Fungal spores in a small mammal scat from Teakettle. Fungal fruiting bodies make up a key component of small mammal diet at certain times of the year in mixed-conifer forests. Keying out by the features you can see here allows genus-level identifications whereas molecular techniques allow us to match these to roots at roughly a species level.
page last updated 9/24/04