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Question How does the interaction between silicon ( Si) and vegetation affect local and global ecological processes, higher levels of ecological organization, and terrestrial- and watershed-scale Si fluxes? Location We selected several ecosystems throughout the world, from river headwaters to estuaries, being examples of (i) terrestrial vegetation, (ii) aquatic and floodplain vegetation, and (iii) tidal wetland vegetation. Methods We provide examples of the importance of linking Si use by terrestrial and aquatic vegetation, to larger-scale Si flux consequences towards and through rivers. Cross-disciplinary studies achieve the best understanding of vegetation effects on the global Si cycle, and the role of Si as a plant functional trait. Conclusion Si use by plants has not always received the research attention of other elements. Yet, today the importance of Si for plant functioning is slowly becoming better understood. Silicon is a crucial element for many plant species, being important for decomposition processes, plant competitiveness and stress tolerance. The inclusion by vegetation scientists of Si uptake as a plant functional trait is important to assess links between plant physiology, plant distribution and plant tolerance to environmental changes, but also to understand the role of vegetation on Si fluxes through the watershed. However, lack of knowledge regarding the biological control of the Si cycle hinders accurate quantification. Only a concerted effort bringing scientists together from a broad array of disciplines will provide this new direction for research on vegetation- Si cycling. [ABSTRACT FROM AUTHOR]

We measured tree damage and mortality following a catastrophic windthrow in permanent plots in an oak forest and a pine forest in centralMinnesota. We monitored changes in forest structure and composition over the next fourteen years. Prior to the storm, the oak forest was dominated by Quercus ellipsoidalis, and the pine forest by Pinus strobus. The immediate impacts of the storm were to differentially damageand kill large, early-successional hardwoods and pines. Subsequent recovery was characterized by the growth of late-successional hardwoods. In both forests the disturbance acted to accelerate succession. Ordination of tree species composition confirmed the trend of accelerated succession, and suggested a convergence of composition between thetwo forests. [ABSTRACT FROM AUTHOR]

The study of vegetation dynamics in tallgrass prairie in response tofire has focused on dormant season fire in late successional prairies. Our objective was to determine if late season fire of varying frequency results in divergent successional patterns in an early successional tallgrass prairie disturbed by grazing and cultivation. Specifically, we evaluated the influence of late-summer fires of varying frequency on community composition and species richness. We collected vegetation and environmental data on two sites burned in the late growing-season at varying frequencies. These communities differed in composition depending primarily on edaphic factors, time since the last burn, and year-to-year variation. We interpret the time effect as related to changes in species composition accompanying plant succession that followed disturbance either from cropping and heavy grazing on the loamy site or heavy grazing on the shallow site. Other unidentified factors also have a role in vegetation dynamics on this prairie. Community composition and species richness were not consistently responsive to frequency of growing-season fires. [ABSTRACT FROM AUTHOR]