Dominance ecological

Savannas are defined as tropical herbaceous ecosystems in which a more or less continuous grass cover formed mainly by C4 grass species represents the dominant ecological element shrubs or trees may be present or not, but they never form a closed canopy (Huber and Riina, 1997). The reference to C4 grasses indicates that savannas are typically lowland or upland vegetation types (c.0-1500 m a.s.L), thus differing ecologically and floristically from tropical... 

Nahlik, A.M. and Mitsch, W. J., Tropical treatment wetlands dominated by free-floating macrophytes for water quality improvement in Costa Rica, Ecological Engineering, 28, 246-257, 2006. 

The energetics depicted in this way are in accord with the microbial ecology observed at deep sea hydrothermal systems (e.g., Kelley el al., 2002 Huber el al., 2003 Schrenk et al, 2003). Sediments and black smoker walls invaded by hydrothermal fluids there contain sparse microbial populations of mostly thermophilic methanogens and sulfate reducers. Abundant populations of mesophilic aerobes dominated by sulfide reducers, in contrast, are found in the open ocean where hydrothermal fluids mix freely with seawater. 

Likewise, this process [12] may also be carried out either as a solvent-free (baking) method or in the presence of solvents. Although initially performed as a solvent-free technique, it is the solvent version that currently dominates the field of copper phthalocyanine production from phthalic anhydride and urea. It should be mentioned, however, that this trend has been reversed in the very recent past and that solvent-free methods are gaining interest, especially for ecological reasons. 

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