Abstract
Dependence of the properties of root systems on the size of the root system may alter conclusions about differences in plant growth in different environments and among species. To determine whether important root system properties changed as root systems aged and accumulated biomass, we measured three important properties of fine roots (tissue density, diameter, and C:N) and three biomass ratios (root:shoot, fine:coarse, and shallow:deep) of monocultures of 10 North American grassland species five times during their second and third years of growth. With increasing belowground biomass, root tissue density increased and diameter decreased. This may reflect cortical loss associated with the aging of roots. For non-legumes, fine root C:N decreased with increasing root biomass, associated with decreases in soil solution NO3 − concentrations. No changes in fine root C:N were detected with increasing belowground biomass for the two legumes we studied. Among all 10 species, there were generally no changes in the relative amounts of biomass in coarse and fine roots, root:shoot, or the depth placement of fine roots in the soil profile as belowground biomass increased. Though further research is needed to separate the influence of root system size, age of the roots, and changes in nutrient availability, these factors will need to be considered when comparing root functional traits among species and treatments.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Caldwell M M, Dawson T E and Richards J H 1998 Hydraulic lift: Consequences of water efflux from the roots of plants. Oecologia 113, 151-161.
Caldwell M M and Richards J H 1986 Competing root systems: morphology and models of absorption. In On the Economy of Plant Form and Function. Ed. T J Givnish. pp. 251-273. Cambridge University Press, Cambridge.
Coutts M P 1987 Developmental processes in tree root systems. Can. J. For. Res. 17, 761-767.
Craine J M, Tilman D G, Wedin D A, Reich P B, Tjoelker M J and Knops J M H in press The relationship between plant functional strategies and growth in a low-nitrogen habitat. Funct. Ecol.
Eissenstat D and Yanai R 1997 The ecology of root lifespan. Adv. Ecol. Res. 27, 2-60.
Eissenstat D M 1997 Trade-offs in root form and function. In Ecology in Agriculture. Ed. L E Jackson. pp. 173-199. Academic Press, Inc., San Diego, California, USA
Fisher M J, Rao I M, Ayarza M A, Lascano C E, Sanz J I, Thomas R J and Vera R R 1994 Carbon storage by introduced deep-rooted grasses in the South American savannas. Nature 371, 236-238.
Fitter A 1991 The ecological significance of root system architecture an economic approach. In Plant Root Growth: An Ecological Perspective. Ed. D Atkinson. pp. 229-244. Blackwell Scientific Publications Ltd., Oxford, UK.
Gill R, Burke I C, Milchunas D G and Lauenroth W K 1999 Relationship between root biomass and soil organic matter pools in the shortgrass steppe of eastern Colorado. Ecosystems 2, 226-236.
Gleeson S K and Tilman D 1994 Plant allocation, growth rate and successional status. Funct. Ecol. 8, 543-550.
Habib R and Lafolie F 1991 Water and nitrate redistribution in soil as affected by root distribution and absorption. In Plant Root Growth: An Ecological Perspective. Ed. D Atkinson. pp. 131-146. Blackwell Scientific Publications, Ltd., Oxford, UK.
Jackson R B, Mooney H A and Schulze E D 1997 A global budget for fine root biomass, surface area, and nutrient contents. Proc. Natl. Acad. Sci. USA 94, 7362-7366.
Jobbágy E G and Jackson R B 2000 The vertical distribution of soil organic carbon and its relation to climate and vegetation. Ecol. Appl. 10, 423-436.
Körner C 1984 Biomass fractionation in plants: a reconsideration of definitions based on plant functions. In A Whole Plant Perspective on Carbon-Nitrogen Interactions. Ed. J Roy and E Garnier. pp. 173-185. SPB Academic Publishing, Inc., The Hague.
McConnaughay K D M and Coleman J S 1999 Biomass allocation in plants: ontogeny or optimality? A test along three resource gradients. Ecology 80, 2581-2593.
Nambiar E K S 1987 Do nutrients retranslocate from fine roots? Iufro (International Union Of Forestry Research Organization) Working Party Meeting On Roots In Forest Soils: Biology And Symbioses, Victoria, British Columbia, Canada, August 4-8, 1986. Can J For Res 17, 913-918.
Nepstad D C, De Carvalho C R, Davidson E A, Jipp P H, Lefebvre P A, Negreiros G H, Da Silva E D, Stone T A, Trumbore S E and Vieira S 1994 The role of deep roots in the hydrological and carbon cycles of Amazonian forests and pastures. Nature 372, 666-669.
Norby R J 1994 Issues and perspectives for investigating root responses to elevated atmospheric carbon dioxide. Plant and Soil 165, 9-20.
Poorter H and Garnier E 1996 Plant growth analysis: An evaluation of experimental design and computational methods. J. Exp. Bot. 47, 1343-1351.
Reynolds H L and D'Antonio C 1996 The ecological significance of plasticity in root weight ratio in response to nitrogen: Opinion. Plant and Soil 185, 75-97.
Ryser P 1996 The importance of tissue density for growth and life span of leaves and roots: A comparison of five ecologically contrasting grasses. Funct. Ecol. 10, 717-723.
Ryser P and Lambers H 1995 Root and leaf attributes accounting for the performance of fast-and slow-growing grasses at different nutrient supply. Plant and Soil 170, 251-265.
Tilman D and Wedin D 1991 Plant traits and resource reduction for five grasses growing on a nitrogen gradient. Ecology 73, 685-700.
Tjoelker M G, Oleksyn J and Reich P B 1998 Temperature and ontogeny mediate growth response to elevated CO2 in seedlings of five boreal tree species. New Phytologist 140, 197-210.
Van Noordwijk M, Brouwer G, Koning H, Meijboom F W and Grzebisz W 1994 Production and decay of structural root material of winter wheat and sugar beet in conventional and integrated cropping systems. Agric. Ecosyst. Environ. 51, 99-113.
Walters M B, Kruger E L and Reich P B 1993 Relative growth rate in relation to physiological and morphological traits for northern hardwood tree seedlings: Species, light environment and ontogenetic considerations. Oecologia 96, 219-231.
Weaver J E and Zink E 1945 Extent and longevity of seminal roots of certain grasses. Plant Physiol. 21, 201-217.
Wedin D A and Tilman D G 1993 Competition among grasses along a nitrogen gradient: Initial conditions and mechanisms of competition. Ecol. Monogr. 63, 199-229.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Craine, J.M., Wedin, D.A., Chapin III, F.S. et al. The dependence of root system properties on root system biomass of 10 North American grassland species. Plant and Soil 250, 39–47 (2003). https://doi.org/10.1023/A:1022817813024
Issue Date:
DOI: https://doi.org/10.1023/A:1022817813024