Precise estimation of root biomass is important for understanding carbon stocks and dynamics in forests. Traditionally, biomass estimates are based on allometric scaling relationships between stem diameter and coarse root biomass calculated using linear regression (LR) on log-transformed data. Recently, it has been suggested that nonlinear regression (NLR) is a preferable fitting method for sca...

Root systems serve important roles in carbon (C) storage and resource acquisition required for the increased photosynthesis expected in CO2-enriched atmospheres. For these reasons, understanding the changes in size, distribution and tissue chemistry of roots is central to predicting the ability of forests to capture anthropogenic CO2. We sampled 8000 cm(3) soil monoliths in a pine forest expose...

Paper birch (Betula papyrifera Marsh) seedlings were grown in a greenhouse in either subsoil or topsoil in factorial combination with two fertilization and drought regimes to investigate how different soil environments and nutrient availability drive belowground partitioning between growth, secondary metabolism and ectomycorrhizal (EM) associations, and impact drought tolerance of paper birch. ...

Genetic modification of shoot and root morphology has potential to improve water and nutrient uptake of wheat crops in rainfed environments. Near-isogenic lines (NILs) varying for a tillering inhibition (tin) gene and representing multiple genetic backgrounds were phenotyped in contrasting, controlled environments for shoot and root growth. Leaf area, shoot and root biomass were similar until t...

BACKGROUNDS AND AIMS Nitrogen nutrition of legumes, which relies both on atmospheric N2 and soil mineral N, remains a major limiting factor of growth. A decade ago, breeders tried to increase N uptake through hypernodulation. Despite their high nodule biomass, hypernodulating mutants were never shown to accumulate more nitrogen than wild types; they even generally displayed depressed shoot grow...

Macro and micro-elements, carbon sources and elicitors play a central role during Panax ginseng hairy root growth, biomass and ginsenoside production and also influence numerous root developmental stages in largescale bioreactor culture. Due to the lack of biosynthetic nutrients and signalling-inducing nutrients, the regulatory role of mineral elements is not well understood. We have geneticall...

Although plastic root-foraging responses are thought to be adaptive, as they may optimize nutrient capture of plants, this has rarely been tested. We investigated whether nutrient-foraging responses are adaptive, and whether they pre-adapt alien species to become natural-area invaders. We grew 12 pairs of congeneric species (i.e., 24 species) native to Europe in heterogeneous and homogeneous nu...

UNLABELLED PREMISE OF THE STUDY Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. • METHODS AND RESULTS Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite), a soil-less industry standard conifer medium, and a custom-m...

Adjustment of ecosystem root respiration to warmer climatic conditions can alter the autotrophic portion of soil respiration and influence the amount of carbon available for biomass production. We examined 44 published values of annual forest root respiration and found an increase in ecosystem root respiration with increasing mean annual temperature (MAT), but the rate of this cross-ecosystem i...

Bolinder, M. A., Angers, D. A., Bélanger, G., Michaud, R. et Laverdière, M. R. 2002. Root biomass and shoot to root ratios of perennial forage crops in eastern Canada. Can. J. Plant Sci. 82: 731–737. Shoot to root ratios (S:R) at peak standing crop are commonly used to estimate the annual crop residue C inputs to the soil from the root biomass left in the soil at harvest. However, root biomass ...