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Table 1 CWM and functional diversity indices used to describe the functional structure of the forests evaluated

From: Assessing above-ground biomass-functional diversity relationships in temperate forests in northern Mexico

Index Expression Description
CWM CWMx =  ∑ pixi CWMx is the CWM for the trait x, pi is the relative abundance of species i in the community, and xi is the trait value for the species i.
RaoQ \( \mathrm{RaoQ}=\sum \limits_{i=1}^S\sum \limits_{j=1}^S{d}_{ij}{p}_i{p}_j \) pi and pj are the relative abundances of species i and j, and the dij values are the dissimilarities between species i and j in the community.
FRic \( \left({Kx}_{a_1}+\left(1-K\right){x}_{b_1},{Kx}_{a_2}+\left(1-K\right){x}_{b_2},\dots, {Kx}_{a_T}+\left(1-K\right){x}_{b_T}\ \right)\ \mathrm{for}\ 0\le K\le 1 \) a and b are species inside the convex hull volume, whose coordinates, i.e., trait values, are (xa1, xa2, ..., xaT) and (xb1, xb2, ..., xbT), respectively.
FEve \( \mathrm{FEev}=\frac{\sum \limits_{l=1}^{S-1}\min \left({\mathrm{PEW}}_l,\frac{1}{S-1}\right)-\frac{1}{S-1}}{1-\frac{1}{S-1}} \)
with
\( {\mathrm{PEW}}_l=\frac{{\mathrm{EW}}_l}{\sum \limits_{l=1}^{S-1}{\mathrm{EW}}_l} \)
and
\( {\mathrm{EW}}_l=\frac{\mathrm{dist}\left(i,j\right)}{w_i+{w}_j} \)
EW is weighted evenness; dist(i, j) is the Euclidean distance between species i and j, the species involved is branch l, and wi is the relative abundance of species i. PEW is the partial weighted evenness; S is number of species.
FDis \( \mathrm{FDis}=\frac{\sum {a}_j{z}_j}{\sum {a}_j} \)
and
\( \mathbf{c}=\left[{c}_i\right]=\frac{\sum {a}_j{x}_{ij}}{\sum {a}_j} \)
aj is the abundance of species j and zj is the distance of species j to the weighted centroid c, where c is the weighted centroid in the i-dimensional space, and xij the attribute of species j for trait i.
FDiv \( \mathrm{FDiv}=\frac{2}{\pi}\arctan (5V) \)
with
V =  ∑ pi(lnxi − ln x)2
and
\( {p}_i=\frac{a_i}{\sum {a}_i} \)
5 is a scaling factor used to define the index over a range of 0–1, and V is the weighted variance of trait x. Inxi is the trait value for the species i; ai is the relative abundance of species i in the community.