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The present study was conducted in a semideciduous Brazilian forest to verify whether there were architectural differences during development among tree species that differ in adult stature, such that understorey species maximise light interception and canopy and emergent species maximise height gain to rapidly reach high light environments. The crown illumination index and light interception index of individual trees as well as the variation in form among the understorey species were also analysed. Two understorey, one canopy and one emergent species were chosen, and the individuals were divided into height classes. Architectural comparisons among individuals were evaluated using allometry; crown illumination and light interception indices were compared among species. All comparisons were made within each height class. The two understorey species presented some differences in growth form, but both exhibited greater investment in the crown than did the canopy and emergent species. The crown illumination index did not differ among species, but the light interception index was higher for the understorey species. The results indicated that architectural differences between the studied species arise predominantly because species belong to different strata of the forest. Comparison within height classes was important because it allowed us to evaluate species architectural characteristics throughout plant development that cannot be detected using a single height-class comparison or that can be neglected if individuals of different heights are compared.

Afforestation and fire exclusion are pervasive threats to tropical savannas. In Brazil, laws limiting prescribed burning hinder the study of fire in the restoration of Cerrado plant communities. We took advantage of a 2017 wildfire to evaluate the potential for tree cutting and fire to promote the passive restoration of savanna herbaceous plant communities after destruction by exotic tree plantations. We sampled a burned pine plantation (Burned Plantation); a former plantation that was harvested and burned (Harvested & Burned); an unburned former plantation that was harvested, planted with native trees, and treated with herbicide to control invasive grasses (Native Tree Planting); and two old-growth savannas which served as reference communities. Our results confirm that herbaceous plant communities on post-afforestation sites are very different from old-growth savannas. Among post-afforestation sites, Harvested & Burned herbaceous communities were modestly more similar in composition to old-growth savannas, had slightly higher richness of savanna plants (3.8 species per 50-m 2), and supported the greatest cover of native herbaceous plants (56%). These positive trends in herbaceous community recovery would be missed in assessments of tree cover: whereas canopy cover in the Harvested & Burned site was 6% (less than typical of savannas of the Cerrado), the Burned Plantation and Native Tree Planting supported 34% and 19% cover, respectively. By focusing on savanna herbaceous plants, these results highlight that tree cutting and fire, not simply tree planting and fire exclusion, should receive greater attention in efforts to restore savannas of the Cerrado.

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