Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae) and springtails (Collembola) in a polder habitat

Abstract

Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder “Ingelheim” to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and strong precipitation. Carabid beetle diversity and evenness decreased marginally when ecological flooding was absent. Springtails represent a less mobile arthropod order, and as such the impact of ecological flooding was stronger. An increase in both numbers of species and individuals of hygrophilic and hygrotolerant species occurred in the flood-disturbed location after ecological flooding. After the sites at both locations had dried, the number of individuals belonging to these species declined rapidly. In contrast to carabid species, the strong precipitation event showed no influence on hygrophilic springtail species. Thus, collembolan diversity and evenness decreased markedly in the absence of flooding. We showed that ecological flooding has an influence on the spatial and temporal dynamics of different arthropod groups that inhabit the polder “Ingelheim”. These findings demonstrate the importance of using different arthropod groups as bioindicators in determining the ecological value of a particular polder design.

Short‐term resilience of arthropod assemblages after spring flood, with focus on spiders (Arachnida: Araneae) and carabids (Coleoptera: Carabidae)

“…Additionally, species richness of spiders reached the same level as non-flooded meso-hygrophilous grasslands between 10 and 20 days after the floodwater had receded, whereas species richness of carabids did not, even after more than 20 days. This is in accordance with the findings of Gerisch et al (2012) for carabids after a summer flood but contrary to numerous studies stating that riparian ground beetles are highly resilient to regular and periodic floods (Uetz, 1979;Zulka, 1994;Adis and Junk, 2002;Lessel et al, 2011).…”

“…The low richness of hydrophilic species in flooded sites is in opposition with Lessel et al . () who found an increased number of hygrophilic species with increasing soil moisture. The long period without spring flood in the Loire Valley (8 years) could have allowed eurytopic species to colonize grasslands and exclude hygrophilic species.…”

“…This is in accordance with the findings of Gerisch et al . () for carabids after a summer flood but contrary to numerous studies stating that riparian ground beetles are highly resilient to regular and periodic floods (Uetz, ; Zulka, ; Adis and Junk, ; Lessel et al ., ).…”

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

“…Secondly, it offers the opportunity to have a clear abiotic gradient known to impact both plants (Lite, Bagstad & Stromberg ; Violle et al . ) and below‐ground fauna (Russell & Griegel ; Lessel, Marx & Eisenbeis ; Sterzyńska, Shrubovych & Kaprus ). Below‐ground, we considered Collembola as a model group.…”

“…We thus selected a flooding gradient, first because it is a main disturbance world-wide drastically impacting ecosystem properties and functioning (Allan & Castillo 2007). Secondly, it offers the opportunity to have a clear abiotic gradient known to impact both plants (Lite, Bagstad & Stromberg 2005;Violle et al 2011) and below-ground fauna (Russell & Griegel 2006;Lessel, Marx & Eisenbeis 2011;Sterzy nska, Shrubovych & Kaprus 2014). Belowground, we considered Collembola as a model group.…”