Quantifying and disentangling dispersal in metacommunities: how close have we come? How far is there to go?

Much of ecological research centers around discovering the underlying factors for species distribution; three such factors are of central importance: local environment, landscape features and dispersal. While all have been simplified in the past, the recent increase in metapopulation and metacommunity research makes being able to quantify dispersal all that much more necessary. In order to increase our knowledge about metacommunities in the real word, it is clearly time to start thinking critically about whether and how the methods that are currently available for measuring dispersal within metapopulations can be adapted. The goal of this contribution is to present and argue the technical difficulties involved in measuring dispersal within metacommunities through: (1) discussing the merits and pitfalls of some potential direct (e.g., mark-recapture) and indirect methods (e.g., isolation measures, patchiness) for studying the effects of dispersal at the metapopulation and metacommunity level; (2) discuss the types of questions that can be tackled at the metacommunity level in light of methodological decisions; and (3) make the point that the technical difficulties of measuring dispersal for multiple species may leave us with little other options than using indirect methods to estimate dispersal in metacommunities.