Environmental changes in biodiversity hotspot ecosystems of
South Ecuador: RESPonse and feedback effECTs (FOR2730)

Abstract:

Aims We determined the reasons why in nutrient solution increasing Al concentrations>300 ?M inhibited shoot biomass production of Cedrela odorata L., Heliocarpus americanus L., and Tabebuia chrysantha (Jacq.) G. Nicholson while 300 ?M Al stimulated root biomass production of Tabebuia chrysantha. Methods Nutrient concentrations in plant tissue after a hydroponic growth experiment were determined. Results Increasing Al concentrations significantly decreased Mg concentrations in leaves. Phosphorus concentrations in roots of C. odorata and T. chrysantha were significantly highest in the treatment with 300 ?M Al and correlated significantly with root biomass. Conclusions Shoot biomass production was likely inhibited by reduced Mg uptake, impairing photosynthesis. The stimulation of root growth at low Al concentrations can be possibly attributed to improved P uptake.