Ph.D. candidate, Forest Sciences, UBC V
Interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) is an obligate ectomycorrhizal tree species with broad host receptivity. Under natural conditions, we expect that Douglas-fir seedlings are colonized with native EM by linking into a common mycelial network (CMN) with neighboring trees. Unsuccessful regeneration of outplanted Douglas-fir seedlings on logged sites in the Interior Douglas-fir (IDF) biogeoclimatic zone of British Columbia may be partly due to poor, early ectomycorrhiza formation. In the dry IDF forest, Douglas-fir seedlings may require linkage into the CMN to survive, reduce water stress, and their growth and competitiveness may also benefit from the association. CMN may provide support to establishing seedlings by reducing plant competition, and increasing C, nutrient, and water uptake.
My research will determine whether the CMN can improve Douglas-fir survival, growth, mycorrhizal formation, and carbon transfer in the dry Interior Douglas-fir biogeoclimatic zone. The specific objectives of my thesis are:
- To determine the influence of CMNs and net C transfer on survival, growth, physiology, and ectomycorrhizal status of outplanted and naturally regenerated Douglas-fir
- To determine the influence of donor size and soil disturbance on i) net C transfer via the CMN and ii) survival, growth, physiology, and ectomycorrhizal status of outplanted and naturally regenerated Douglas-fir
- To assess indirect facilitation of Douglas-fir establishment by advanced regeneration Douglas-fir.
- I have described 45 unique morphotypes from mature trees potentially linking planted seedlings via CMN.
- Cooccurrence analyses show that seedlings are sharing many of the same rhizomorph-forming morphotypes such as Amphinema, Piloderma, Rhizopogon, and Suillus spp.
- Optimum growth and reduced stress of seedlings planted near mature trees occurs at distances between 1 and 5 m from mature trees.
- Lower survival of Douglas-fir seedlings has been observed when mycorrhizal networks are excluded.
Teste, P.F., M.G. Schmidt, S.M. Berch, C.E. Bulmer, and K.N. Egger. 2004. Effects of ectomycorrhizal inoculants on survival and growth of Interior Douglas-fir seedlings on reforestation sites and partially rehabilitated landings. Canadian Journal of Forest Research 34: 2074-2088
Krzic, M., C.E. Bulmer, F.P. Teste, L. Dampier, and S. Rahman. 2004. Soil properties influencing compactability of forest soils in British Columbia. Canadian Journal of Soil Science 84:219-226.
Teste, F.P., Karst, J., Jones, M.D., Simard, S.W., and Durall, D.M. (2006) Methods to control ectomycorrhizal colonization: effectiveness of chemical and physical barriers Mycorrhiza, in press.
Schoonmaker, A.L., Teste, F.P., Simard, S.W., and Guy, R.D. (2006) Tree proximity and soil pathways: their influence on utilization of redistributed water by understory seedlings. Oecologia, submitted December 2006.
Last reviewed 5/8/2013 6:26:28 PM