THE ECTOTROPHIC MYCORRHIZAS OF <i>ALNUS VIRIDIS</i> (CHAIX) D.C. AND THEIR SIGNIFICANCE IN RESPECT TO PHOSPHORUS UPTAKE

Abstract

S ummary Three subtypes of mycorrhizas, sensu Dominik (1955), were found on roots of Alnus viridis growing in New Zealand. Roots with 60% of their rootlets mycorrhizal absorbed phosphate five times as rapidly as non‐mycorrhizal roots. Root nodules appear unable to absorb labelled phosphorus actively from externally supplied solution.