Does low phosphorus supply limit seedling establishment and tree growth in groves of ectomycorrhizal trees in a central African rainforest?

Abstract

• In a forest grove at Korup dominated by the ectomycorrhizal species Microberlinia bisulcata , an experiment tested whether phosphorus (P) was a limiting nutrient. • P-fertilization of seven subplots 1995-97 was compared with seven controls. It led to large increases in soil P concentrations. Trees were measured in 1995 and 2000. M. bisulcata and four other species were transplanted into the treatments, and a wild cohort of M. bisulcata seedlings was followed in both. Leaf litter fall from trees and seedlings were analysed for nutrients. • Growth of trees was not affected by added P. Transplanted seedlings survived better in the controls than added-P subplots: they did not grow better with added-P. M. bisulcata wildlings survived slightly better in the added-P subplots in yr 1 but not later. Litter fall and transplanted survivors had much higher concentrations of P (not N) in the added-P than control subplots. • Under current conditions, it appears that P does not limit growth of trees or hinder seedling establishment, especially of M. bisculcata , in these low-P grove soils.