Appendix S1.
We sampled environmental variables that are likely related to different
species requirements in a restinga forest. We quantified soil
moisture, canopy opening, elevation, terrain slope, flooding height, and
litterfall height in a 1-ha, permanent plot of restinga forest in
southeastern Brazil. The plot was divided into 100 subplots of 10 m 10 m
(Joly et al. , 2012). Soil moisture was determined as the
volumetric soil water content measured at the centre of each subplot at
12-cm depth with a HS2 Hydrosense II sensor (Campbell Scientific, Logan,
Utah, USA).
We obtained the percentage of canopy opening from hemispheric
photographs taken at the centre of each subplot at two different
moments, 2008 and 2017, as recent light environment should influence
smaller plants and past light environment likely influenced large trees
as they were growing (Poorter, 2007). In 2008, two digital cameras with
similar settings were used, a Nikon Coolpix 950 and a Nikon Coolpix
5000, both with a fisheye lens Nikon FC E8 (Eisenlohr et al. ,
2013). In 2017, we took the photographs using a Nikon D7200 digital
camera with Sigma fisheye lens 4.5 mm f/2.8 EX DC and similar settings
from 2008. At the two moments, the cameras were positioned on a tripod
with the lens facing upwards at 1.3 m from the soil surface and parallel
to it, with the magnetic north at the top of the photographs (Eisenlohret al. , 2013). The photographs were taken when the sky was
uniform and showed high contrast with the canopy, between 8 h - 10 h and
15 h - 17 h (Rich, 1990). All photographs were processed with the
software Gap Light Analyzer (Frazer et al. , 1999) in order to
obtain the relative proportion of black and white (representing canopy
opening) pixels.
We calculated the elevation of each subplot as the mean elevation of the
four corners delimiting the subplots (data from the Functional Gradient
Project Biota/FAPESP 03/12595-7 – available upon request). Terrain
slope was calculated as the difference between the maximum and the
minimum elevation of the four corners of each subplot (Rodrigueset al. , 2007). We considered flooding height as the height of the
water column during the rainy season (January 2017). We measured water
column and litterfall height at four diagonal points 3.5 m from each
corner of the subplots using a graduated stake (Souza and Martins,
2005). Therefore, flooding height and litterfall height were measured at
a 5 m 5 m scale, while soil moisture, canopy opening, elevation, and
terrain slope were obtained at a 10 m 10 m scale. The values of the
variables measured are presented in Figure A1.