The long term fertilization plots are designed to investigate the effect of nutrient addition on tropical ecosystem processes. The fertilization will be conducted in 2016 in three contrasting topographic positions (top, slope, bottom-land) associated with a fertility gradient. In each of these three positions, there will be four 50 x 50 m plots with different treatments respectively: +N, +P, +NP and control (the later located inside the Plot 15). In these plots we will conduct various measurements, dealing with soil biology, plant ecology and physiology, food webs or gas emissions. By integrating this information we will better understand the mechanisms which govern plant-soil-atmosphere interactions in a tropical area with very low nutrient availability in the soil but with very high accumulation of alive biomass.