Metacommunity ecology has enhanced our understanding of how structured communities function, helping us to manage natural resources more effectively in an increasingly fragmented world. Key differences in the dominant metacommunity paradigms are interspecific variation in dispersal and competitive abilities. Previous works have found that differences in functional traits, such as leg length in amphibians or physiological tolerance in fishes, can influence the way these factors affect the dynamics of stable metacommunities. However severe disturbances can cause large portions of a metacommunity to face extirpation, after which it must re-assemble. This re-assembly period is analogous to first assembly, affording the opportunity for scientists to study how metacommunities first assembled largely in the absence of priority effects. How do functional traits influence species sorting at first assembly? The Rocky Glades region of Everglades National Park is a karst, short hydroperiod, shallow marsh where solution holes serve as longer hydroperiod refuges for fishes during the unnaturally long and severe dry seasons of the modern Everglades. Solution holes are thus high quality patches in a low quality matrix that is seasonally linked by dispersal, are communities in an ephemeral metacommunity, where fish communities non-randomly assemble at the start of the dry season. Our previous work in this system suggests that distance from a source community and patch complexity explain a significant portion of the variance in annual re-assembly. As the time fish are able to disperse varies between years, the functional traits of each species with relation to these factors should also influence the patch community. To investigate this, we sampled solution hole communities to depletion annually for three years and characterized key morphological and ecological traits of select species. We asked how these functional traits influenced metacommunity assembly in this annually extirpated metacommunity.
Results/Conclusions
A severe drought in the final year of sampling caused a severely reduced dispersal window, which resulted in an increased importance of distance from the source on aquatically limited species, while a prolonged dry down period in the first year reduced this effect. However, regardless of year, terrestrially capable fishes showed no relationship to this factor suggesting that hydrologic connectivity is less important in determining their community membership than other factors. The influence of patch complexity was related to individual life history, with spawning fish exclusively found in less complex sites. This study demonstrates that individual morphological and ecological traits can have notable effects on metacommunity assembly.