Restoring riparian habitats improves functional diversity of dragonfly and damselfly
Odonates (dragonflies and damselflies) are reliable bio-indicators to evaluate the quality of riparian and terrestrial habitats as they are sensitive to water quality, habitat modification and the presence of invasive alien plants. In the present study, Odonate populations were sampled at 45 sites along 6 rivers in North-eastern South Africa. Fifteen sites were sampled in three habitat types including, (1) invaded (where the cover of invasive plants was greater than 20 % of the identified vegetation), (2) cleared of invasive plants, and (3) natural sites (consisting of native vegetation). The invaded sites included the non-native species Pinus patula, Eucalyptus grandis and Caesalpinia decapetala – species which have been shown to significantly reduce water availability. In total, 1151 Odonates consisting of 45 species were identified during the study. Species richness of Odonates showed no difference between habitat types. However, functional diversity (a measure of the number of functionally disparate species within a population) was lower in invaded sites compared to sites cleared of invasive plants and sites with native vegetation. Therefore, the study highlights that Odonate functional diversity can respond positively to restoration efforts.
Sources
Modiba RV, Joseph GS, Seymour CL, Fouche P, Foord SH (2017) Restoration of riparian systems through clearing of invasive plant species improves functional diversity of Odonate assemblages. Biological Conservation 214, 46-54.