Rapid root assimilation of added phosphorus in a lowland tropical rainforest of French Guiana
Van Langenhove,L., I.A.Janssens, L.Verryckt, L.Brechet, I.P.Hartley, C.Stahl, E.Courtois, I.Urbina, O.Grau, J.Sardans, G Peguero, A.Gargallo-Garriga, J.Peñuelas and S.Vicca. 2020.
Abstract
Tree growth on weathered soils in lowland tropical forests is limited by low phosphorous (P) availability. However, nutrient manupulation experiments do not always increase the P content in these trees, which raises the question whether trees are taking up added P. In French Guianese lowland rainforest, we measured changes in nitrogen (N) and P availability before and up to two months after N and P fertilizer addition, in soils with intact root systems and in soils where roots and mycorrhizal fungi were excluded by root exclusion cylinders. When the root system was excluded, P addition increased P availability to a much greater extent and for a longer time than in soils with an intact root system. Soil N dynamics were unaffected by root presence/absence. These results indicate rapid P uptake, but not N uptake, by tree roots, suggesting a very effective P acquisition process in these lowland rainforests.
Key Words
Tropical forest; Phosphorus; Nitrogen; Fertilization; Root system; Plant root simulator probes
