Determinant landscape‐scale factors on pond odonate assemblages

Abstract

Species assemblages are related to environmental factors acting at different landscape scales. Local habitat heterogeneity also contributes to maintain the regional species pool. Understanding factors determining species presence is therefore crucial for formulation of successful conservation and management strategies. Odonates can reveal much about patterns of species assemblages since their presence at a site reflects both their dispersal ability and life cycle constraints. Odonate assemblages were studied at 31 ponds located in three different landscapes: forest, urban and field. The impact of pond geographical distribution and their local characteristics (i.e., vegetation, suspended matter, freshwater macroinvertebrates, pond area and temporariness) on odonate composition, species richness and larval presence were studied. According to their intrinsic requirements, damselfly and dragonfly presence on ponds depended on local characteristics. Some species of the two orders were only detected in field or forest ponds. Moreover, some species were never detected in urban ponds. Differences in odonate assemblages were mainly related to vegetation, freshwater macroinvertebrates and pond area. Species richness was related to predator abundance and pond area, especially for dragonflies. The presence and abundance of odonate larvae were both related to aquatic vegetation, and to contrasted aquatic variables of ponds. Therefore, this study confirms that vegetation within and around ponds determines odonate presence. Interestingly, in a pond, species detected at the adult stage were not always detected at the larval stage, highlighting the need to really consider both parts of the lifecycle when studying odonate assemblages. Diversity of local habitats within and around ponds depends strongly on the surrounding landscape and influences the assembly of odonates. Forest and field ponds presented particularly dissimilar species assemblages. Urban ponds had no specific environmental habitats compared to the other contexts. Species present on these ponds are rather generalist and able to support human disturbances. Overall, this study confirms that pond heterogeneity may be a key factor in maintaining the regional pool of odonate species.

Spatial context strongly affects community composition of both passively and actively dispersing pool invertebrates in a highly heterogeneous landscape

“…These have typically univoltine or semivoltine life cycles in Central Europe (Corbet, ), and are more likely to choose larger pools as suitable breeding sites because of the lower risk of drying out and higher availability of prey. Increasing habitat size was also found to promote odonate diversity in other studies covering comparable metacommunity scales (57 ponds and lakes in Michigan, McCauley et al., ; 31 ponds in France, Le Gall, Fournier, Chaput‐Bardy, & Husté, ). A similar effect of habitat size on species richness was also observed in odonates, but not in aquatic beetles and molluscs, in Swiss ponds (Oertli, Joye, & Castella, ).…”

Landscape-scale terrestrial factors are also vital in shaping Odonata assemblages of watercourses

“…Another group of studies reveal the major importance of connectivity between water bodies for Odonata 15,23–25 . Only a small number of studies targets Odonata assemblages using both local and landscape variables as predictors to understand their occurrence, abundance and community structure 4,10,26 .…”

Ecological drivers of Odonata beta diversity in arid and semi‐arid regions of the Central Plateau of Iran

“…This result is in contrast with findings from other studies, which suggest landscape variables play important role in shaping Odonata assemblages (e.g. Tsubaki & Tsuji, 2006; Le Gall et al ., 2018; Renner et al ., 2018; Mendes et al ., 2019; Nagy et al ., 2019). Over recent decades, the speed of land use change and disturbance has been very high in the arid and semi‐arid areas of Iran (Heidarlou et al ., 2019; Kabir et al ., 2020).…”