Effects of wetland hydroperiod length on the functional structure of assemblages of Odonata

Abstract

The role of hydroperiod as an environmental filter in structuring wetland assemblages is usually associated with trait selection in invertebrates. However, the effects of changes in the hydroperiod of non-permanent wetlands on invertebrate assemblages are still unclear, and few studies have assessed the functional structure of insect assemblages along the hydroperiod gradient. In this study, we investigated the effects of different hydroperiod lengths on the functional structure of Odonata assemblages in non-permanent wetlands (posteriorly classified as 'short-', 'medium-' and 'long-hydroperiod') in southern Brazil in 2013 and 2014. Biological traits related to life-history strategies in temporary waters were assessed according to seasonal patterns of occurrence of nymphal and adult stages of odonates. Following the rationale of an environmental filter produced by hydroperiod, we expected to find (1) higher functional diversity in longer hydroperiods and (2) trait-convergence patterns in odonate assemblages in shorter hydroperiods. Patterns of functional diversity were detected along the hydroperiod gradient. More specifically, higher functional dispersion was found in long-hydroperiod wetlands and trait-convergence patterns occurred in wetlands with shorter hydroperiods, supporting our general hypothesis. Odonate taxa with life-history traits associated with shorter life cycles predominated in medium-and short-hydroperiod wetlands. Our results thus suggest that more pronounced reductions in wetland hydroperiod length should produce odonate assemblages functionally more similar, and these results gain special importance as climate change scenarios indicate that the hydrology of wetlands will be affected by variation in rainfall regimes.

Spatiotemporal assembly patterns of macroinvertebrate metacommunity structure in subtropical wetlands with different hydroperiods

“…In relation to the categories of hydroperiod length, we monitored the surface flooding areas of each wetland over two full hydrological cycles. Monthly surveys were carried out from September 2011 to September 2013 (Bieger, 2015;Boelter et al, 2018;Knauth et al, 2018;Pires et al, 2017Pires et al, , 2019Stenert et al, 2017). We used as classification criteria the length of the wet phase, the number of drought events, and the surface flooding area of each wetland over the monitoring period.…”

Recognizing the enemy: do predator cues influence hatching in Neotropical annual killifish?

“…), which occurs in ponds isolated from perennial water bodies usually alone or with coexisting non‐annual fish species in reduced abundance. In this region, ponds have a short hydroperiod and may face two flood cycles in the same year (Knauth et al ., 2019; Pires et al ., 2019). The coexisting non‐annual fish species contain potential predators ( e.g., Hoplias spp.)…”

Patterns of co‐occurrence and body size in dragonflies and damselflies (Insecta: Odonata) in preserved and altered Amazonian streams

“…As few studies have elucidated the role of competition in structuring odonate communities, the competition between closely related species would be expected to be more intense and likely to cause habitat segregation (Pires et al . 2017; Cerini et al . 2019).…”

“…Although the deterministic theory on the distribution of species in the community prevails in community ecology (Grant 1972;Diamond 1975;Stone & Roberts 1990), many papers have shown that well-defined distribution patterns are absent in many communities (Volkov et al 2003;McGill et al 2006). As few studies have elucidated the role of competition in structuring odonate communities, the competition between closely related species would be expected to be more intense and likely to cause habitat segregation (Pires et al 2017;Cerini et al 2019).…”