This is not exactly the answer you're looking for if you want comprehensive, but I've seen a presentation about the capacity of mangroves to sequester carbon by Catherine Lovelock last year. I do not know if she has published this or not.

Have you seen this paper? May be a good jumping off point: http://www.esajournals.org/doi/abs/10.1890/110004

There are good data for seagrasses. See recent papers by

This one too

And finally

These are all seagrasses, but there's a good literature on mangroves too.