A global budget for fine root biomass, surface area, and nutrient contents

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 94; no. 14; pp. 7362 - 7366
• Main Authors: Jackson, R.B. (University of Texas at Austin, Austin, TX.), Mooney, H.A, Schulze, E.D
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 08-07-1997; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences of the USA
• Subjects: AREA DE SUPERFICIE; Biological Sciences; BIOMASA; BIOMASS; BIOMASSE; Biomes; Boreal forests; Botany; CARBON; CARBONE; CARBONO; Coniferous forests; CONTENIDO DE NITROGENO; Deciduous forests; Ecology; Flowers & plants; FOSFORO; Grassland soils; LARGURA; LENGTH; LONGUEUR; NITROGEN CONTENT; NUTRITIVE VALUE; PHOSPHORE; PHOSPHORUS; Plant roots; PLANTAS; PLANTE; PLANTS; RACINE; RAICES; Root biomass; ROOT SYSTEMS; ROOTS; SISTEMA RADICULAR; Soil ecology; Soils; SURFACE; SURFACE AREA; Surface areas; SYSTEME RACINAIRE; TENEUR EN AZOTE; VALEUR NUTRITIVE; VALOR NUTRITIVO
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.94.14.7362

Global biogeochemical models have improved dramatically in the last decade in their representation of the biosphere. Although leaf area data are an important input to such models and are readily available globally, global root distributions for modeling water and nutrient uptake and carbon cycling have not been available. This analysis provides global distributions for fine root biomass, length, and surface area with depth in the soil, and global estimates of nutrient pools in fine roots. Calculated root surface area is almost always greater than leaf area, more than an order of magnitude so in grasslands. The average C:N:P ratio in living fine roots is 450:11:1, and global fine root carbon is more than 5% of all carbon contained in the atmosphere. Assuming conservatively that fine roots turn over once per year, they represent 33% of global annual net primary productivity.