Four distinct meteorological regimes in the Amazon basin have been examined to distinguish the contributions from boundary layer aerosol and convective available potential energy (CAPE) to continental cloud structure and electrification. The lack of distinction in the electrical parameters (peak flash rate, lightning yield per unit rainfall) between aerosol‐rich October and aerosol‐poor November in the premonsoon regime casts doubt on a primary role for the aerosol in enhancing cloud electrification. Evidence for a substantial role for the aerosol in suppressing warm rain coalescence is identified in the most highly polluted period in early October. The electrical activity in this stage is qualitatively peculiar. During the easterly and westerly wind regimes of the wet season, the lightning yield per unit of rainfall is positively correlated with the aerosol concentration, but the electrical parameters are also correlated with CAPE, with a similar degree of scatter. Here cause and effect are difficult to establish with available observations. This ambiguity extends to the “green ocean” westerly regime, a distinctly maritime regime over a major continent with minimum aerosol concentration, minimum CAPE, and little if any lightning.

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Abbreviations CT = compositional turnover; PT = phylogenetic turnover; FT = species-based functional turnover; iFT = individual-based functional turnover. Nomenclature APG (2009) AbstractQuestions: Humid savannas can be considered fire-filtered landscapes because fire is very frequent (<10 yr return intervals) and only fire-resistant species can occur. This flammable vegetation can be functionally heterogeneous, structurally and floristically patchy. We hypothesized that resource availability (mainly water and nutrient availabilities) accounted for most of the functional and phylogenetic spatial structure of communities across these savanna landscapes.Location: Emas National Park, central Brazil.Methods: We used individual-based functional trait, phylogenetic and environmental data combined with spatial information to assess the main drivers and mechanisms of community functional change (turnover) in a large fire-filtered savanna landscape. We used Mantel correlograms and a maximum rank correlation approach to assess the spatial structure and the subset of landscape factors that best predict compositional, phylogenetic, species-based and individualbased functional community turnovers and the mechanism by which they do operate.Results: Communities were spatially structured across the landscape, presenting functional convergence at shorter distances and divergence at larger distances. All of the turnover metrics presented unique spatial structures and were correlated with a unique set of landscape predictors. Soil texture accounted for the largest fraction of the spatial structure, but soil N availability, pH, altitude and fire frequency were also important. Conclusions:Our results support the idea that the patchy distribution of water and nutrients mediated by clay content shape community membership in firefiltered savannas, whereas current variations in fire frequency interact with resource availability to shift community attributes from species average trait values (intraspecific variability).