AJPS  Vol.4 No.6 , June 2013
The Relative Importance of Nitrogen vs. Moisture Stress May Drive Intraspecific Variations in the SLA-RGR Relationship: The Case of Picea mariana Seedlings
Abstract: Plants acclimate to nitrogen (N) or moisture stress by respectively increasing photosynthetic N use efficiency (PNUE) or water use efficiency (WUE), in order to maximize their relative growth rate (RGR). These two phenotypic adaptations have opposite effects on specific leaf area (SLA). Thus, intraspecific variations in the SLA-RGR relationship should reflect the relative importance of N vs. moisture stress in plants. In this study, we measured needle gas exchanges and N concentrations in order to derive PNUE and WUE, as well as SLA and RGR of black spruce (Picea mariana) seedlings growing on a rapidly drained site in the presence or absence of Kalmia angustifolia. The eradication of Kalmia had resulted in a ~140% increase in seedling growth over a 6 year period. We found a negative SLA-RGR relationship where Kalmia had been eradicated, and a positive one where Kalmia had been maintained. Kalmia eradication resulted in higher WUE when measurements were made directly on the seedlings, and in lower PNUE when twigs were rehydrated prior to gas exchange measurements. Our data suggest that the bigger seedlings on Kalmia-eradicated plots increase RGR by decreasing SLA, as a means of coping with moisture stress. By contrast, increasing SLA on noneradicated plots may be a means of coping with nutrient stress exerted by Kalmia. The SLA-RGR relationship could potentially be used to identify the limiting resource for black spruce seedlings in different environments.
Cite this paper: P. LeBel, R. Bradley and N. Thiffault, "The Relative Importance of Nitrogen vs. Moisture Stress May Drive Intraspecific Variations in the SLA-RGR Relationship: The Case of Picea mariana Seedlings," American Journal of Plant Sciences, Vol. 4 No. 6, 2013, pp. 1278-1284. doi: 10.4236/ajps.2013.46158.

[1]   R. Aerts, “Interspecific Competition in Natural Plant Communities: Mechanisms, Trade-Offs and Plant-Soil Feedbacks,” Journal of Experimental Botany, Vol. 50, No 330, 1999, pp. 29-37.

[2]   Y. Osone, A. Ishida, and M. Tateno, “Correlation between Relative Growth Rate and Specific Leaf Area Requires Associations of Specific Leaf Area with Nitrogen Absorption Rate of Roots,” New Phytologist, Vol. 179, No. 2, 2008, pp. 417-427. doi:10.1111/j.1469-8137.2008.02476.x

[3]   H. Lambers and H. Poorter, “Inherent Variation in Growth Rate between Higher Plants—A Search for Physiological Causes and Ecological Consequences,” Advances in Ecological Research, Vol. 23, 1992, pp. 187-261. doi:10.1016/S0065-2504(08)60148-8

[4]   B. Li, J.-I. Suzuki and T. Hara, “Latitudinal Variation in Plant Size and Relative Growth Rate in Arabidopsis thaliana,” Oecologia, Vol. 115, No. 3, 1998, pp. 293-301. doi:10.1007/s004420050519

[5]   P. Meerts and E. Garnier, “Variation in Relative Growth Rate and Its Components in the Annual Polygonum aviculare in Relation to Habitat Disturbance and Seed Size,” Oecologia, Vol. 108, No. 3, 1996, pp. 438-445. doi:10.1007/BF00333719

[6]   A. Biere, “Intra-specific Variation in Relative Growth Rate: Impact on Competitive Ability and Performance of Lychnisflos cuculi in Habitats Differing in Soil Fertility,” Plant and Soil, Vol. 182, No. 2, 1996, pp. 313-327.

[7]   T. L. Pons, A. Van der Werf and H. Lambers, “Photosynthetic Nitrogen Use Efficiency of Inherently Slow- and Fast-Growing Species: Possible Explanations for Observed Differences,” In: J. Roy and E. Garnier, Eds., A Whole-Plant Perspective of Carbon-Nitrogen Interactions, SPB Academic Publishing, The Hague, 1994, pp. 61-77.

[8]   M. G. Letts, K. N. Nakonechny, K. E. Van Gaalen and C. M. Smith, “Physiological Acclimation of Pinus flexilis to Drought Stress on Contrasting Slope Aspects in Waterton Lakes National Park, Alberta, Canada,” Canadian Journal of Forest Research, Vol. 39, No. 3, 2009, pp. 629-641. doi:10.1139/X08-206

[9]   P. B. Reich, M. G. Tjoelker, M. B. Walters, D. W. Vanderklein and C. Bushena, “Close Association of RGR, Leaf and Root Morphology, Seed Mass and Shade Tolerance in Seedlings of Nine Boreal Tree Species Grown in High and Low Light,” Functional Ecology, Vol. 12, No. 3, 1998, pp. 327-338. doi:10.1046/j.1365-2435.1998.00208.x

[10]   U. Niinemets, “Global-Scale Climatic Controls of Leaf Dry Mass Per Area, Density, and Thickness in Trees and Shrubs,” Ecology, Vol. 82, No. 2, 2001, pp. 453-469. doi:10.1890/0012-9658(2001)082[0453:GSCCOL]2.0.CO;2

[11]   K. R. Hultine and J. D. Marshall, “Altitude Trends in Conifer Leaf Morphology and Stable Carbon Isotope Composition,” Oecologia, Vol. 123, No. 1, 2000, pp. 32-40. doi:10.1007/s004420050986

[12]   L. M. de Montigny and G. F. Weetman, “The Effects of Ericaceous Plants on Forest Productivity,” In: B. D. Titus, M. B. Lavigne, P. F. Newton and W. J. Meades, Eds., The Silvics and Ecology of Boreal Spruce, Canadian Forest Service, Forestry Canada, St. John’s Newfoundland, 1990, pp. 83-90.

[13]   P. LeBel, N. Thiffault and R. L. Bradley, “Kalmia Removal Increases Nutrient Supply and Growth of Black Spruce Seedlings: An Effect Fertilizer Cannot Emulate,” Forest Ecology and Management, Vol. 256, No. 10, 2008, pp. 1780-1784. doi:10.1016/j.foreco.2008.02.050

[14]   J. P. Saucier, A. Robitaille and P. Grondin, “Cadre Bio-Climatique du Québec. écologie Forestière,” In: R. Doucet, Ed., Manuel de Foresterie, 2nd Edition, éditions Multimondes, Québec, 2009, pp. 186-205.

[15]   Soil Classification Working Group, “The Canadian System of Soil Classification,” 3rd Edition, Agriculture and Agri-Food Canada, NRC Research Press, Ottawa, 1998.

[16]   N. Thiffault, B. D. Titus and A. D. Munson, “Black Spruce Seedlings in a Kalmia-Vaccinium Association: Microsite Manipulation to Explore Interactions in the Field,” Canadian Journal of Forest Research, Vol. 34, No. 8, 2004, pp. 1657-1668. doi:10.1139/x04-046

[17]   R. Hunt, “Basic Growth Analysis,” Unwin Hyman, London, 1990.

[18]   I. J. Walinga, J. van der Lee, V. J. G. Houba, W. van Vark and I. Novozamsky, “Plant Analysis Manual,” Kluwer Academic Publishers, Dordrecht, 1995. doi:10.1007/978-94-011-0203-2

[19]   A. K. Mitchell and T. M. Hinckley, “Effects of Foliar Nitrogen Concentration on Photosynthesis and Water-Use Efficiency in Douglas Fir,” Tree Physiology, Vol. 12, No. 4, 1993, pp. 403-410. doi:10.1093/treephys/12.4.403

[20]   J. D. Stewart and P.-Y. Bernier, “Gas Exchange and Water Relations of 3 Sizes of Containerized Picea mariana Seedlings Subjected to Atmospheric and Edaphic Water-Stress Under Controlled Conditions,” Annals of Forest Science, Vol. 52, No. 1, 1995, pp. 1-9. doi:10.1051/forest:19950101

[21]   R. Jobidon, L. Charette and P.-Y. Bernier, “Initial Size and Competing Vegetation Effects on Water Stress and Growth of Picea mariana (Mill.) BSP Seedlings Planted in Three Different Environments,” Forest Ecology and Management, Vol. 103, No. 2-3, 1998, pp. 293-305. doi:10.1016/S0378-1127(97)00228-4

[22]   G. D. Joanisse, R. L. Bradley, C. M. Preston and A. D. Munson, “Soil Enzyme Inhibition by Condensed Litter Tannins May Drive Ecosystem Structure and Processes: The Case of Kalmia angustifolia,” New Phytologist, Vol. 175, No. 3, 2007, pp. 535-546. doi:10.1111/j.1469-8137.2007.02113.x

[23]   G. D. Joanisse, R. L. Bradley, C. M. Preston and G. D. Bending, “Sequestration of Soil Nitrogen as Tannin-Protein Complexes May Improve the Competitive Ability of Sheep Laurel (Kalmia angustifolia) Relative to Black Spruce (Picea mariana),” New Phytologist, Vol. 181, No. 1, 2009, pp. 187-198. doi:10.1111/j.1469-8137.2008.02622.x

[24]   M. S. Lamhamedi, P.-Y. Bernier, C. Hébert and R. Jobidon, “Physiological and Growth Responses of Three Sizes of Containerized Picea mariana Seedlings Outplanted with and without Vegetation Control,” Forest Ecology and Management, Vol. 110, No. 1-3, 1998, pp. 13-23. doi:10.1016/S0378-1127(98)00267-9

[25]   H. C. Muller-Landau, “The Tolerance-Fecundity Trade-Off and the Maintenance of Diversity in Seed Size,” Proceedings of the National Academy of Science, Vol. 107, No. 9, 2010, pp. 4242-4247. doi:10.1073/pnas.0911637107