A decadal-scale qualitative comparison of lotic Odonata nymph surveys in northwestern Pennsylvania, USA, reveals possible assemblage restructuring

Abstract

Freshwater ecosystems, recognized as hotspots of biodiversity, are under increasing threat from human activities. Odonata, the iconic inhabitants of these ecosystems, are highly sensitive to changes in habitat morphology, hydrology and land-use dynamics. In this study, the odonate assemblages in four different regions in northeastern Algeria are investigated to identify the key environmental factors that influence them. These regions differ in terms of climate, altitude and land use. Over the course of the study, we documented twenty-one species, including ten Zygoptera and eleven Anisoptera, which together account for a substantial proportion (~47%) of regional odonate diversity. Species composition is correlated with habitat typology and land cover. Multivariate analyses revealed distinct ecological patterns, highlighting streambed width, flow velocity and, to a lesser extent, land cover and altitude as influential factors in assemblage segregation. This study underscores the importance of flow velocity, which is known to facilitate oxygen uptake by larvae and influence the distribution and composition of species. Altitude, a key factor influencing phenology, growth and development, and land use (including forests, urbanization, agriculture and pasture) are also identified as potential determinants of odonate assemblages. To effectively tailor conservation strategies to specific regional conditions around the world, the study emphasises the importance of identifying the key environmental factors affecting odonate assemblages.

Keywords: Odonata, freshwater ecosystems, hotspots, landscape cover, land use, North Africa

Issue section: Original Article

Also in this issue

Life cycle and seasonal regulation of Onychogomphus forcipatus unguiculatus in the Seybouse River, Algeria (Insecta: Odonata)

The final-instar larva of Bayadera strigata Davies & Yang, 1996 from Yunnan, China (Odonata: Zygoptera: Euphaeidae)

Gomphomacromia signata sp. n. from the Andes Mountains in Ecuador (Odonata: Synthemistidae)

Description of Phylloneura rupestris sp. n. (Odonata, Platycnemididae) from the Western Ghats, India, with notes on its reproductive behaviour

Increased geographic sampling suggests incomplete lineage sorting and recent introgression between Pyrrhosoma nymphula (Sulzer, 1776) and P. elisabethae Schmidt, 1948 in the Western Palearctic

Rare and endangered Odonata of Lebanon – an update with a discussion on the vanishing Levant endemic dragonfly fauna

Paleoecological niche modeling of Epiophlebia (Epiophlebioptera: Epiophlebiidae) reveals continuous distribution during the Last Glacial Maximum

Geographical variation in size of the three final stadia of Cordulegaster boltonii (Donovan, 1807) larvae in the Iberian Peninsula (Odonata: Cordulegastridae)

Evaluation of speculated reproductive habitat for Somatochlora calverti (Corduliidae), a rare and range-restricted dragonfly

Reproductive behavior of Erythrodiplax abjecta (Rambur, 1842) from Andean Mountains

Commented checklist of the Odonata from Colombia

Demography and natural history of the damselfly Mesamphiagrion gaudiimontanum (Coenagrionidae), a Páramo endemic species in the Colombian Andes

A decadal-scale qualitative comparison of lotic Odonata nymph surveys in northwestern Pennsylvania, USA, reveals possible assemblage restructuring

Land use and beyond: unraveling environmental determinants of odonate assemblages in northeastern Algeria