Dragonflies (Insecta: Odonata) as indicators of habitat quality in Mediterranean streams and rivers in the province of Barcelona (Catalonia, Iberian Peninsula)

Abstract

In a field study carried out in 2011 and 2014 adult dragonflies were identified as a rapid and easy-to-use means of assessing habitat quality and biological integrity of Mediterranean streams and rivers in the province of Barcelona (Region Catalonia, Iberian Peninsula). The study included sampling sites from five different river catchments: Besòs, Foix, Llobregat, Ter and Tordera. Multivariate statistical procedures and indicator species analysis were used to investigate the relationship between river ecological status, study sites and dragonfly species or species assemblages' occurrence. The dragonfly association identified with western Mediterranean permanent streams, i.e. Cordulegaster boltonii, Boyeria irene, Onychogomphus uncatus and Calopteryx virgo meridionalis, was found only at the sites with the highest status. All these taxa were identified as indicator species of sites with the best scores for the macroinvertebrate based IBMWP index and for the combined IASPT index, which reflects the sensitivity of the macroinvertebrate families present to environmental changes; besides, B. irene and C. virgo meridionalis also proved to be indicator species of the riparian forest quality index and C. boltonii of the more inclusive ECOSTRIMED, which assesses the overall conservation status of the riverine habitats. The information obtained on habitat preferences and indicator value showed that adults of these taxa may constitute a valuable tool for preliminary or complementary cost-effective monitoring of river status and restoration practices as part of a broader set of indices reflecting biodiversity and ecosystem integrity.

How suitable are man-made water bodies as habitats for Odonata?

“…On the other hand, species richness was lower in comparison with some natural wetland habitats (Vilenica et al, 2011;Kulijer, 2012;De Knijf et al, 2013). However, the sampling method has certain limitations, as it may under-collect representative larvae given the rather small area of habitat/microhabitat captured by the sampling net (Horning and Pollard, 1978;Martín and Maynou, 2016).…”

<em>Boyeria irene</em> (Fonscolombe, 1838) y <em>Cordulegaster boltonii</em> (Donovan, 1807) (Odonata): dos estrategias en cuanto a sustratos de emergencia de larvas en un mismo hábitat

“…Nuestros datos muestran que la proporción de sus exuvias (y, por tanto, de larvas F-0) es aproximadamente 1:2, siendo C. boltonii más numerosa. El tramo de río analizado es de aguas frías, con pendiente elevada y velocidad media de corriente de 10,4 km h -1 , factores que son propios para el desarrollo de C. boltonii en ecosistemas lóticos mediterráneos (Martín & Maynou, 2016). Por el contrario, B. irene es más termófila (Ocharan & Torralba Burrial, 2004), por lo que esta zona de río no es tan adecuada para ella.…”

Ecological traits of dragonfly (Odonata) assemblages along an oligotrophic Dinaric karst hydrosystem

“…Antonović and Treer, 2015). However, this is also potentially due to limitations of the sampling method which may under-collect representative larvae as the nets cover only a small area of a habitat/ microhabitat (Horning and Pollard, 1978;Hawking and New, 1999;Martín and Maynou, 2016). Even though the studies focusing on dragonfly adults are the most common, they could sometimes show inaccurate results, as adults have high dispersal abilities and could often be found far from the place of their emergence (e.g.…”