Interspecific transfer of inorganic materials by root systems of woody plants.
The interspecific transfer of inorganic materials by exudation from and reabsorption by roots of plants growing in mixed hardwood/Pine forest in the South Carolina sandhills was studied by means of radioactive isotopes, which were introduced to potential 'donor' trees (healthy selected specimens of Carya pallida and Quercus marilandica) either by felling the trees and applying isotopes in aqueous solution to the stumps, or by leaving the trees intact and inserting isotopes under the bark with hypodermic syringes. The isotopes thus introduced were transferred to 35% of the potential 'receptors', i.e. 25-35 randomly selected trees or shrubs not more than12.19 m. from each donor. Transfer to 84% of the actual receptors occurred within 4 days. Of the possible receptors not more than1.52 m. distant from a donor, <more than>50% received isotopes. Of four isotopes used, P was transferred more readily than Ca, Rb and S. Movement of isotopes within the roots was probably passive rather than metabolic. [Cf. F.A. 26 No. 3446.KEYWORDS: Carya pallida \ Quercus marilandica \ Roots \ Roots exudations \ excretions \ Roots nodules \ Roots water relations \ uptake