Is climate a stronger driver of tree growth than disturbance? A comment on Toledo et al. (2011)

1. A recent article published by Toledo et al. (2011b) investigates the effects of spatial variations in climate and soil, and of logging disturbance, on tree and forest growth in Bolivia. It concludes that climate is the strongest driver of tree and forest growth and that climate change may therefore have large consequences for forest productivity and carbon sequestration. However, serious methodological and conceptual discrepancies have been found that challenge these conclusions. 2. Because of an errant coding of 'time after logging' in the regression analysis, and because floristic changes induced by logging could not be incorporated into the analysis, the effect of logging on the average diameter growth is likely to have been strongly underestimated. 3. Basal area growth was improperly calculated as basal area change, and it displayed surprisingly high values, even among unlogged plots. We hypothesize that either these plots may be actually located in secondary forests recovering from past logging, or measurement biases may have hampered the data set. 4. Regardless of climate-growth relationships established across these plots, any inference concerning the potential effects of climate change on forest growth would require a specific quantitative assessment. 5. Synthesis. It is critical to re-assess the relative weight of climate and logging disturbance as driving factors of tree and forest growth, and to find an explanation for the very high basal area increment reported among the unlogged plots. We provide specific recommendations for further analyses of this and similar data sets.

Bibliographic Details

Main Authors:	Ferry, Bruno, Bontemps, Jean-Daniel, Blanc, Lilian, Baraloto, Christopher
Format:	article biblioteca
Language:	eng
Subjects:	P40 - Météorologie et climatologie, F62 - Physiologie végétale - Croissance et développement, K10 - Production forestière, forêt tropicale, changement climatique, croissance, dendrométrie, exploitation forestière, évaluation de l'impact, http://aims.fao.org/aos/agrovoc/c_24904, http://aims.fao.org/aos/agrovoc/c_1666, http://aims.fao.org/aos/agrovoc/c_3394, http://aims.fao.org/aos/agrovoc/c_16209, http://aims.fao.org/aos/agrovoc/c_7775, http://aims.fao.org/aos/agrovoc/c_37938, http://aims.fao.org/aos/agrovoc/c_331403,
Online Access:	http://agritrop.cirad.fr/565408/ http://agritrop.cirad.fr/565408/1/document_565408.pdf
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