Root systems of two Patagonian shrubs: A quantitative description using a geometrical method

FERNANDEZ, R. J.; PARUELO, J. M.

JOURNAL OF RANGE MANAGEMENT

Society for Range Management

Año: 1988 vol. 41 p. 220 - 223

0022-409X

A method for mapping coarse root distribution suitable for stony soils was developed. Each root is considered as a broken line, whose segments are fairly straight root portions. The spatial location of end points of these segments is recorded in the field through 3 coordinates: its distance from plant vertical axis, its depht and its distance to the foregoing point ont the same root. With these data the roots' spatial arrangement is reproduced using a computer program including simple geometrical relationships. The main advantages of the method are: (a) it does not require sample harvesting and handling; (b) it considers root length instead of root biomass; and (c) its quiantitative character allow statistically valid comparisons. Two species living in the Patagonian semidesert were studied: neneo (Mulinum spinosum, Umbeliferae) and mata mora (Sencio filaginoides, Compositae). In both shrubs, roots extended laterally more than 2m and root length decreases exponentially as the distance from the canopy edge increases. Neneo was found to have its maximal root density at a depth of 0.4 m, whereas mata mora has most of its roots close to the soil surface. An interpretation of the differential response of these shrubs to grazing derives from this results.