Data from: Floristic and structural heterogeneity in a Neotropical riparian wetland: Conservation implications

Despite the incontrovertible importance of wetland ecosystems, our
understanding of the causes underlying the spatial heterogeneity of their
attributes is still insufficient. Here, we assess the spatial variation of
the floristics (species composition and their relative abundances) and
quantitative structure (vegetation cover) of the San Pedro Mártir River
riparian herbaceous wetlands (Tabasco, Mexico), and explore potential
factors responsible for within- and among community variation. Vegetation
was sampled at 10 sites along a 40-km stretch of the river. Per site cover
of the recorded morphospecies was assessed with digital photography, and
community diversity was analyzed using the Hill numbers framework. Total
richness was 76 morphospecies (67 identified to some taxonomic category);
the drastic decrease in true diversity with increasing q values indicated
that few species dominate the community matrix, while numerous remaining
species occupy the small interstices among them. Three Cyperaceae species
had the largest importance in the community, with Cladium jamaicense being
the most frequent and having the largest cover along the river. Ward’s
site classification and NMDS ordination indicated the existence of four
floristically and structurally different vegetation groups. Within sites,
GLMMs showed a weak inverse relationship between species richness and
distance from the river, but no relationship for plant cover. Fluvial
geomorphology, and possibly regional geological heterogeneity, are the
main factors determining the spatial variation of these herbaceous
wetlands. Deep understanding of the relationship of herbaceous riparian
wetlands with their environment will improve the prediction of the effects
of modifications of fluvial dynamics and support efficient conservation
strategies.