Analyses of benthic macroinveritebrate colonization during the early successional phases of created wetlands in temperate Asia

We quantified the colonization rate and pattern of benthic macroinvertebrate communities in 2 created small-sized wetlands (non-planted and planted) and a nearby older man-made wetland in Korea. We sampled benthic macroinvertebrates at monthly intervals and surveyed the vegetation dynamics every 2 months from May 2009 to October 2010. We determined the colonization rate using the newly adopted colonization index (CI), and evaluated the colonization pattern using multivariate analyses, including nonmetric multidimensional scaling (NMS) and indicator species analysis (ISPAN). As predicted, the species richness and diversity of benthic macroinvertebrates increased markedly in early successional phases in the 2 created wetlands, and initial planting accelerated colonization of benthic macroinvertebrate communities; in comparison, the older man-made wetland showed a more gradual increase. The CI (range 100-0) decreased over time in the created wetlands; this decrease was more rapid in the planted wetland than in the non-planted wetland. After 400 Julian days, the benthic macroinvertebrate community in the planted wetland showed 90% similarity with that in the older man-made wetland. The NMS results revealed that the colonization pattern of benthic macroinvertebrates differed significantly according to vegetation (non-planted versus planted [p = 0.000]), season (p = 0.001), and year (p = 0.014). The ISPAN results showed that the indicator species in the non-planted and planted wetlands were the burrowing mayfly (Ephemera orientalis) and the damselfly (Ischnura asiatica), respectively. Our findings demonstrate the validity of using the CI to quantify the colonization rate of benthic macroinvertebrate communities in typical small-sized temperate wetlands.