Posted on Authorea 27 Sep 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.163277474.41710752/v1 — This a preprint and has not been peer reviewed. Data may be preliminary.
Inﬂuence of landscape homogenization due to river damming on
dragonﬂy (Odonata) community structuring in a subtropical forest
in the southern Atlantic Forest
Breno R. Araujo1,ˆ
Angelo Parise Pinto1, and Andr´e A. Padial2
1Universidade Federal do Parana Departamento de Zoologia
2Universidade Federal do Parana
September 27, 2021
Human activities aﬀect the structure, dynamics, and energy ﬂow of aquatic ecosystems. River damming, a common anthropic
impact in Brazil, changes solar incidence, water ﬂow, and temperature of waterbodies, thereby aﬀecting their fauna. Due to
their high sensitivity to environmental changes, the Odonata may be indicators of these impacts. We sampled two ecologically
distinct sites, (1) a quasi-pristine forested area; and (2) a nearby human-impacted reservoir landscape, to evaluate the eﬀects
of damming on odonate community structure. The species composition of quasi-pristine communities was more heterogeneous
and diﬀered almost completely (indicating high turnover) from that of the reservoir-area communities. The capacity of the
reservoir to maintain local fauna was almost nil. The communities in the changed landscape had the highest local diversity,
which is related to the high occurrence of widespread generalist South American species. We also tested two recently proposed
bioindication ratio tools based on the abundance of high-level taxonomic categories; both eﬀectively demonstrated the extent of
the impacts of damming. The best performing ratios were Coenagrionidae/other Zygoptera richness ratio, Zygoptera/Anisoptera
abundance ratio, and Libellulidae/other Anisoptera richness ratio. The reservoir landscape promotes biotic homogenization.
However, the water supply system entails the preservation of part of the native habitat in its surrounding areas, consequently
maintaining local biodiversity in quasi-pristine environments.
2021_Araujo_et_al_Manuscrit_Main_Doc_EcoHydrology_Submission_Revised.docx available at