The role of canopy cover dynamics over a decade of changes in the understory of an Atlantic beech-oak forest

This dataset hosts the main data and R codes of the analyses
carried out to study the role of canopy cover dynamics over a decade of
changes in the understory of an Atlantic Beech-Oak forest. We measured
changes in understory taxonomical and functional composition, richness and
diversity between 2006 and 2016, and relate those changes to changes in
canopy coverage between both years. The data show changes between 2006 and
2016 in the species abundance, richness and diversity of 102
understory communities, and in the functional composition, richness and
diversity for five functional traits (Leaf dry matter content, Specific
leaf area, Leaf size, Plant height and Seed mass). Changes in
canopy coverage between 2006 and 2016 were studied as an explanatory
variable. The R codes show the main analyses carried out in
the study: 1) The calculation of the functional composition,
richness and diversity of the five traits studied (Leaf dry matter
content, Specific leaf area, Leaf size, Plant height and Seed mass),
2) a Dunnett’s modified Tukey-Kramer test used to test
for significant relationships between four plot categories defined
according to the presence or absence of canopy gaps (no gaps, gap closure,
gap opening and gap persistence) and changes in the taxonomical and
functional composition and diversity of the understory from 2006 to 2016.
3) An Indicator Species Analysis used to study the species that
were indicators of gap opening or closure in the Atlantic
Beech-Oak forest studied. 4) The calculation of the Standardized Effect
Size for the functional traits of the indicator species, used to
see if the species selected as gap indicators shared similar values of
functional traits and had values significantly different from
non-indicator species.