Competitive effects of three tropical tree species on two species of Piper.

altura biological competition biomasa biomass biomasse cedrela odorata cordia alliodora costa rica crecimiento croissance densidad density euphorbiaceae growth hauteur height humid tropics inhibition leaf area ombrage piper plant anatomy racine roots shading sotobosque stems superficie foliar surface foliaire tallo tige tropiques humides umbria undergrowth