... δ13C, stable carbon isotope composition.1. INTRODUCTIONApplication of fertiliser often increases the growth of Pinuspinaster Ait. and other conifers [24, 38]. The mass and area of foliage increases ... photo-synthesis and Rubisco concentration. Most studies relating N,P and K nutrition to photosynthesis and Rubisco have focussed on a handful of well-studied herbaceous species. Of the fewstudies on ... lasting role of Amax in the growthresponse. Concentrations of N, P, and K were maintainedwithin a relatively small range, and there was no correlationbetween Amax and concentrations of N, P,...