Ecological Archives E088-070-A2

Steven I. Higgins, William J. Bond, Edmund C. February, Anfries Bronn, Douglas I. W. Euston-Brown, Beukes Enslin, Navashni Govender, Louise Rademan, Sean O'Regan, Andre L. F. Potgieter, Simon Scheiter, Richard Sowry, Lynn Trollope, and Winston S. W. Trollope. 2007. Effects of four decades of fire manipulation on woody vegetation structure in savanna. Ecology 88:1119–1125.

Appendix B. Estimating tree biomass.

We use a meta-analysis published by Netshiluvhi and Scholes (2001) for our above ground woody biomass (M) estimates. They use results from several studies that estimate M (kg) from stem diameter (d, cm) in southern African savannas. Their meta-analysis suggests that a reasonable general equation for southern African savannas is,

M=0.0375d2.55

For this study we need to estimate biomass from height. We used height and diameter data collected in the Kruger National Park (W.J. Bond , unpublished) to estimate stem diameter (cm) as a simple linear function of height (m),

d=2.797h,

the adjusted-R2 for this regression is 0.87. Combining these two equations yields an equation for above ground tree biomass (kg) as function of tree height (m):

M=0.52hd.255

The above ground woody biomass estimates generated using this equation (see Fig. 2 in the main manuscript) are consistent with estimates provided by a recent review of savannas (Grace et al. 2006).

LITERATURE CITED

Grace, J., J. San Jose, H. S. Miranda, and R. A. Montes. 2006. Productivity and carbon fluxes of tropical savannas. Journal of Biogeography 33:387–400.

Netshiluvhi, T. R. and R. J. Scholes. 2001. Allometry of South African woodland trees. CSIR, Division of Water, Environment and Technology; Pretoria.



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