Responses and adaptations of collembolan communities (Hexapoda: Collembola) to flooding and hypoxic conditions

Abstract

-Standard ecological methods (pitfall traps, trunk eclectors and soil cores) were used to evaluate collembolan community responses to different flooding intensities. Three sites of a floodplain habitat near Mainz, Germany, with different flooding regimes were investigated. The structures of collembolan communities are markedly different depending on flooding intensity. Sites more affected by flooding are dominated by hygrophilic and hygrotolerant species, whereas the hardwood floodplain is dominated by mesophilic species. The survival strategies of the hygrophilic and hygrotolerant species include egg diapause and passive drifting. The physiological adaptations to hypoxic conditions of several collembolan species were analyzed using a microcalorimeter. The activities were tested under normoxic and hypoxic/anoxic conditions as well as during post-hypoxic recovery. Lactate was increased after hypoxic intervals in the species studied, suggesting that, in addition to a massive decrease in metabolic rate, a modest glycolytic activity may be involved in the tolerance to hypoxia.Index terms: behavioral adaptation, ecological adaptation, egg diapause, inundation, morphological adaptation, physiological adaptation. Respostas e adaptações de comunidades de colêmbolos (Hexapoda: Collembola) a condições de inundação e hipoxiaResumo -Foram utilizados os métodos ecológicos padrão (armadilhas "pitfall", armadilhas de tronco e amostras de solo) para avaliar as respostas de comunidade de colêmbolos a diferentes intensidades de inundação. Foram investigados três locais de um habitat de leitos de inundação perto de Mainz, Alemanha, com diferentes regimes de inundação. As estruturas das comunidades de colêmbolos foram nitidamente diferentes conforme a intensidade das inundações. Nos locais mais afetados por inundações, as espécies higrofílicas e higrotolerantes dominaram, ao passo que as espécies mesofílicas foram dominantes nos locais de leitos de inundação com angiospermas. As estratégias de sobrevivência das espécies higrofílicas e higrotolerantes incluem a diapausa dos ovos e o deslocamento passivo. Foi testada a adaptação fisiológica a condições hipóxicas de espécies selecionadas de colêmbolos através de análises por microcalorimetria. A atividade das espécies foi testada em condições normóxicas e hipóxicas/anóxicas e durante a recuperação pós-hipoxia. Verificou-se que o lactato aumentava após condições hipóxicas nas espécies avaliadas, o que sugere que, além de um decréscimo massivo na atividade metabólica, deve haver também certa atividade glicolítica associada à tolerância à hipoxia.Termos para indexação: adaptação comportamental, adaptação ecológica, diapausa dos ovos, inundação, adaptação morfológica, adaptação fisiológica.

Soil Fauna of Peat-Forming Wetlands in a Natural River Floodplain

“…However, the spatial replacement of earthworms species documented in our study contradicts the hypothesis according to which only non-flooded sites and depressions where water content remained at relatively high levels seemed to suit best the environmental needs of earthworms (Plum and Filser 2005). The observed variation of the soil macro-and mesofauna communities in peatlands could be related to the varied sensitivity, adaptations and predispositions of soil animal groups to flooding and drought conditions (Marx et al 2009(Marx et al , 2012Xu et al 2012;Rothenbücher and Schaefer 2006) and less stressful hydrologic conditions than those observed in alluvial channel-floodplain river systems (Steiger et al 2005), where different ecological responses of collembolans in peat and non-peat filled river floodplains have been documented (Sterzyńska 2009). The pattern observed across our sampling period of temporal variation in annual water discharge (river flow) that affect the dynamic of river and groundwater flow interactions on an intra-and inter-annual scale not only could provide insight into how species, soil macro-and mesofauna communities and selected taxa tolerate stress due to differences in natural flow regime, but could also shed light on how these factors impact their diversity pattern and response.…”

“…Location of the Biebrza wetlands in Poland and location of studied sites along the Biebrza River floodplain: S1 -reed fen, river fed, S2 -tall sedge fen, river fed, S3 -moss sedge fen, groundwater fed, S4 -swamp forest, groundwater fed; water supply pattern after data base for Biebrza National Park, (http://levis.sggw.pl/ mss/eng/Soil.htm). collembolans (Collembola), which is often used as a model group in conditions of extensive flooding (Marx et al 2009). Terrestrial isopods and millipedes were considered together as they belong to the same trophic guild (Scheu and Falca 2000).…”

Commercial glyphosate-based herbicides effects on springtails (Collembola) differ from those of their respective active ingredients and vary with soil organic matter content

“…Sminthurinus niger is a black, globular springtail (Hexapoda, family Katiannidae) with unclear but most likely ubiquitous distribution in many terrestrial habitats in temperate climates (Fjellberg 2007;Womersley 1931). It is also considered more surface-dwelling (Buşmachiu et al 2015) than the mainly soil-dwelling F. candida (Marx et al 2009), which would explain why there were no individuals of F. candida caught in the pitfall traps. Since we thoroughly homogenized the soil before distributing it among the experimental pots, we assumed an equal distribution of S. niger from the beginning of the experiment.…”

Shifts and linkages of functional diversity between above‐ and below‐ground compartments along a flooding gradient

“…One such mechanism is passive drifting, which has been documented for the Protaphorura genus (Marx et al . ) in flooded riparian areas. Collembola have also been observed climbing on vertical surfaces in order to avoid the rising tide (M. Chauvat, personal observation), and some Collembolan species are known to climb on plants or tree trunks (Ponge ).…”

“…In addition, and contrary to plants that are anchored in the soil, Collembola have several behavioural mechanisms at their disposal in order to escape flooding. One such mechanism is passive drifting, which has been documented for the Protaphorura genus (Marx et al 2009) in flooded riparian areas. Collembola have also been observed climbing on vertical surfaces in order to avoid the rising tide (M. Chauvat, personal observation), and some Collembolan species are known to climb on plants or tree trunks (Ponge 1993).…”