Forest Investment Account (FIA) - Forest Science Program
FIA Project M086018

    Evaluation of the impact of N fertilization on mountain pine beetle success in mature lodgepole pine stands at the leading edge of an infestation
Project lead: McLean, John (University of British Columbia)
Contributing Authors: Jack, David; McLean, John; Weetman, Gordon F.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Nitrogen is one of the key limiting factors for life systems (White 2005) and the lodgepole pine forests of British Columbia are generally deficient in this nutrient (Brockley 2000). Waring and Pitman (1985) reported that improved nitrogen nutrition hastened lodgepole pine tree recovery from attack by the mountain pine beetle (MPB), Dendroctonus ponderosae (Coleoptera:Curculionidae [Scolytinae]) but did not prevent attacks by beetles until growth efficiencies exceeded 100g of wood production per square metre of foliage. The major line of defense for lodgepole pine trees is the dynamic wound reaction (DWR) rather than oleoresin flow alone (Raffa and Berryman, 1982). Excessive N fertilization might render the lodgepole more suitable as a food source for attacking beetles which would be a counterproductive result and one that needs to be allowed for (Herms, 2002). Recent literature reports near isometric scaling of whole- plant respiration, N content and plant mass (Reich et al. 2006) suggesting that additional N would enhance respiration which we will in turn evaluate by the enhancement of the dynamic wound response capabilities of the trees. Experience in the Cascade Forest District in the Southern Interior Forest Region during the summers of 2004 and 2005 showed that 140 year old lodgepole pine responded significantly to a single fertilizer treatment of 200 KgN/ha with longer needle growth and an apparent improved capability to pitch out attacks by the mountain pine beetle. Several trees in the two fertilized stands attacked in 2004 maintained green foliage in 2005, had no additional attacks by the mountain pine beetle and few emergence holes from the 2004 attacks (Coggins and McLean 2005). This project seeks to verify these observations in a fully randomized experiment in a leading edge infestation of mountain pine beetle in a ~120 year old lodgepole pine forest.
References: Brockley, R.P. 2000. Using foliar variables to predict the responses of lodgepole pine to nitrogen and sulphur fertilization. Canadian Journal of Forest Research 30:1389-1399. Coggins, S. and J.A. McLean. 2005. Preliminary observations on mountain pine beetle success in nitrogen fertilized mature lodgepole pine plots. Poster presentation, Mountain Pine Beetle Epidemic Workshop, Vancouver November 7, 2005, , Prince George, B.C. November 9-10, 2005. Herms, D.A. 2002. Effects of fertilization on insect resistance of woody ornamental plants: reassessing an entrenched paradigm. Environmental Entomology 31:923-933. Raffa, K. and A.A. Berryman, 1982. Physiological differences between lodgepole pine trees resistant and susceptible to the mountain pine beetle and associated microorganisms. Environ. Entomol. 11:486-492. Reich, P.B., M.G. Tjoelker, Jose-Luis Machado and J. Oleksyn, 2006. Universal scaling of respiratory metabolism, size and nitrogen in plants. Nature 439:457-461. Waring, R.H. and G. Pitman. 1985. Modifying lodgepole pine stands to change susceptibility to mountain pine beetle attack. Ecology 66(3):889-897. White, T.C.R. 2005. Why does the world stay green? Nutrition and survival of plant eaters. CSIRO Publishing 2005, 128 pp.


Project Report (1.3Mb)
MPB and Nitrogen Fertilization (JEM 2008, Vol. 9, Issue 1)

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Updated August 16, 2010 

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