This is fairly doable. We could easily add a creative commons license to each plot, and allow users to specify such licenses when they upload data. Might include a new observation field to allow plot-by-plot changes of license. This would require a revision of VegBranch. Or, we could include this in the 'ownership/embargoes' of plots and could be edited from default after submission.
Source is section 2.6.2 number 14 of requirements document, page 65