Ecological Archives E094-200-A3

Li-Wan Chang, David Zelený, Ching-Feng Li, Shau-Ting Chiu, Chang-Fu Hsieh. 2013. Better environmental data may reverse conclusions about niche- and dispersal-based processes in community assembly. Ecology 94:2145–2151. http://dx.doi.org/10.1890/12-2053.1

Appendix C. Variation partitioning analysis between environmental (only topographical, only soil, or both) and spatial variables.

FigC1

Fig. C1. Results of variation partitioning into fractions represented by topographical (topo), soil, and spatial variables, reported as adjusted R² on percentage scale (R²adj × 100). Topography is represented by 11 variables, soil by 46 variables and space by 208 dbMEM variables. All testable fractions are significant (p < 0.001, 9999 permutations).


Table C1. Reported explained variation is represented by adjustedR². All testable components ([a], [c], [a+b] and [b+c]) are significant (Monte Carlo permutation test with 9.999 permutations), mostly at p < 0.001; only fraction [a] explained by soil on non-standardized species data is significant at p < 0.01. Results of variation partitioning on non-standardized species composition matrix are provided for comparison with results of Legendre et al. (2009), while variation explained by environmental variables on Hellinger-standardized species composition matrix corrected for total beta diversity (BDTOT) is for comparison with De Cáceres et al. (2012).

Environmental variables

[a]

[b]

[c]

[d]

[a+b]

[b+c]

Hellinger-standardized species composition matrix

topographical

0.013

0.194

0.375

0.418

0.207

0.569

soil

0.009

0.426

0.142

0.422

0.435

0.568

topo + soil

0.022

0.455

0.113

0.410

0.477

0.568

Non-standardized species composition matrix

topographical

0.011

0.234

0.408

0.346

0.245

0.642

soil

0.006

0.430

0.213

0.351

0.436

0.643

topo + soil

0.017

0.473

0.170

0.340

0.490

0.643

Hellinger-standardized species composition matrix, explained variation × BDTOT

topographical

0.006

0.086

0.166

0.185

0.092

0.252

soil

0.004

0.189

0.063

0.187

0.193

0.252

topo + soil

0.010

0.202

0.050

0.182

0.212

0.252

[a] = variation explained by environmental and not by spatial variables, [b] = spatially structured variation explained by environmental variables, [c] = variation explained by spatial variables but not by environmental ones, [d] = unexplained variation, [a+b] and [b+c] = marginal variation explained by environmental and by spatial variables, respectively.

† Values reported for Lienhuachih by De Cáceres et al. (2012, Table S2, size 20 – 20) are slightly different: [a] 0.006, [b] 0.089, [c] 0.163, [d] 0.185, [a+b] 0.095, [b+c] 0.252.

Literature cited

De Cáceres M., P. Legendre, R. Valencia, M. Cao, L.-W. Chang, G. Chuyong, R. Condit, Z. Hao, C.-F. Hsieh, S. Hubbell, D. Kenfack, K. Ma, X. Mi, N.S. Noor, A. R. Kassim, H. Ren, S.-H. Su, I.-F. Sun, D. Thomas, W. Ye, and F. He. 2012. The variation of tree beta diversity across a global network of forest plots. Global Ecology and Biogeography, 21:1191–1202.

Legendre P., X. Mi, H. Ren, K. Ma, M. Yu, I.-F. Sun, and F. He. 2009. Partitioning beta diversity in a subtropical broad-leaved forest of China. Ecology 90:663–674.


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