The dependency of photosynthesis and dark respiration on foliar area-based N (<i>N</i>_area) and P (<i>P</i>_area) across common garden palms, field palms, species from a global dataset and dicotyledonous broad-leaved trees in tropical rain forests (dicot TRF trees).

<p>(a, b) Area-based maximum photosynthetic rate (<i>A</i>_area), (c,d) area-based dark respiration rate (<i>R</i>_area). Relationships in each dataset are significant and their standardized major axis (SMA) regression lines are shown. The differences in SMA regression slope and intercept between common garden palms and two other non-palm datasets are indicated (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140384#pone.0140384.s010" target="_blank">S4 Table</a> for the differences between field palms and two other non-palm datasets). ns, <i>P</i> > 0.05, * <i>P</i> < 0.05, ** <i>P</i> < 0.01, *** <i>P</i> < 0.001.