Effects of Landscape Patterns and Their Changes to Species Richness, Species Composition, and the Conservation Value of Odonates (Insecta)

Abstract

Understanding the impact of the changing proportion of land-use patterns on species diversity is a critical issue in conservation biology, and odonates are good bioindicators of these environmental changes. Some freshwater ecosystems that have been modified due to human activities can serve as important secondary habitats for odonate assemblages; however, the majority of studies addressing the value of secondary habitats in industrial and urban areas for adult dragonfly diversity have been limited to the local scale, and the value of such habitats for gamma diversity is still unclear. The aim of this study was to determine the relationship between human transformations of land use/land cover and dragonfly diversity. We interpolated the information based on dragonfly occurrence per grid cell and land cover data, indicating naturalness and degradation in 677 grid cells in the Czech Republic. Species richness did not correspond to habitat naturalness, but the occurrence of endangered species was significantly positively correlated with increasing naturalness; thus, habitat degradation and/or the level of naturalness significantly affected species composition, while species richness remained unchanged. Threatened species that occur predominantly in natural areas and threatened species with a dominant occurrence in degraded squares were also separated, which indicated that the conservation of the latter should be prioritised.

Odonata Assemblages in Urban Semi-Natural Wetlands

“…As this study shows, the presence of natural habitat features (habitat morphology and vegetation structure) is beneficial for many Odonata species and should be considered in landscape management plans in urban areas to ensure important habitat complexity for aquatic insects such as Odonata [34,56]. Due to the mutual proximity of the study sites, similar values of physico-chemical water properties, generally well-developed aquatic vegetation [37] and the high dispersal mobility of adult Odonata (which allows the possibility that many of the individuals observed at a particular lake emerged from another lake) [57], most of taxonomic assemblage metrics were comparable between the anthropogenically disturbed and natural oxbow lakes, similar to the results of Dolný et al [58].…”

“…Both species prefer to inhabit slow-flowing waters but are also frequently found in well-oxygenated stagnant waters with well-developed aquatic vegetation, such as oxbows and marshes or various man-made habitats (gravel pits, fishponds, canals) [ 57 , 74 ]. Although the values of the Dragonfly Biotic Index were comparable between the two habitat types, at natural oxbow lakes, some species of conservation concern were recorded: Aeshna isoceles and Lestes sponsa [ 48 ], which is consistent with the importance of natural habitat structure, with well-developed aquatic and riparian vegetation and a variety of microhabitats for rare Odonata [ 58 ].…”

Agricultural land use affects the heterogeneity of Odonata communities in the Brazilian Pampa

“…Many authors stress that agricultural land use homogenizes communities by promoting the dominance of a subset of generalist species as well as by constraining the pool of early-colonizing species and limiting the distribution of poor dispersers (Vellend et al 2007;Ekroos et al 2010;Siqueira et al 2015). In this context, most studies on odonates suggest that landscape modification (including conversion to agriculture) affects their communities through the loss of specialist (e.g., forestdependent with restricted home ranges) and weak-dispersing species; most of these studies, however, are centered on forest ecosystems (Dutra and De Marco 2015;Luke et al 2017;de Oliveira-Junior and Juen 2019;Dolný et al 2021). The underlying mechanisms through which agriculture affects biodiversity can vary across taxa and change with local context (Johnson and Angeler 2014;Jonason et al 2017).…”

“…The underlying mechanisms through which agriculture affects biodiversity can vary across taxa and change with local context (Johnson and Angeler 2014;Jonason et al 2017). Nevertheless, considering that the distribution of Odonata depends on the structure of the surrounding terrestrial landscape (Nagy et al 2019;Dolný et al 2021), the effects of agricultural land use on Odonata (and aquatic insects in general) in South American subtropical grasslands (Pampa) should be different than forest-based ecosystems. Here, the shift and differences in the homogeneity of the composition of odonate communities in relation to agricultural land use were not driven either by the loss of species (given the similar richness and similar composition of Anisoptera and Zygoptera between land uses) or by the spatial configuration of the study sites (given the lack of spatial autocorrelation), contrary to most studies.…”

Country‐level checklists and occurrences for the world's Odonata (dragonflies and damselflies)

“…Odonate checklists have been used for identification of habitat associations, establishment of community assemblages or as a basis for site occupancy modelling (e.g. Dolný et al, 2021; Kéry et al, 2010).…”