High Survival of Lasius niger during Summer Flooding in a European Grassland

Abstract

Climate change is projected to increase the frequency of extreme events, such as flooding and droughts, which are anticipated to have negative effects on the biodiversity of primary producers and consequently the associated consumer communities. Here we assessed the effects of an extreme early summer flooding event in 2013 on ant colonies along an experimental gradient of plant species richness in a temperate grassland. We tested the effects of flood duration, plant species richness, plant cover, soil temperature, and soil porosity on ant occurrence and abundance. We found that the ant community was dominated by Lasius niger, whose presence and abundance after the flood was not significantly affected by any of the tested variables, including plant species richness. We found the same level of occupation by L. niger at the field site after the flood (surveyed in 2013) as before the flood (surveyed in 2006). Thus, there were no negative effects of the flood on the presence of L. niger in the plots. We can exclude recolonisation as a possible explanation of ant presence in the field site due to the short time period between the end of the flood and survey as well as to the absence of a spatial pattern in the occupancy data. Thus, the omnipresence of this dominant ant species 1 month after the flood indicates that the colonies were able to survive a 3-week summer flood. The observed ant species proved to be flood resistant despite experiencing such extreme climatic events very rarely.

Plant diversity and functional identity alter ant occurrence and activity in experimental grasslands

“…While L. niger occurred in all plots, most ant species other than L. niger occurred only sporadically, and this extremely high dominance is the likely reason why we did not detect a significant effect of the variables on ant richness. Lasius niger , as well as many other ant species (Hölldobler & Wilson, 1990), is known as a synanthrophic ant that occurs mainly in open, grassy, warm, and dry human‐affected habitats such as meadows or pastures where it can reach high densities and become dominant (Hertzog, Ebeling, et al, 2016). In temperate regions, habitats with intrinsically low diversity and with high dominance of just one or few species often feature more generalist ant species (Dauber & Wolters, 2005), which probably produces a homogenization in the structure of these communities and makes it difficult to detect differences in species richness (Dauber et al, 2006).…”

Response of Collembola and Acari communities to summer flooding in a grassland plant diversity experiment

“…Gamasida are important predators of nematodes, which were negatively affected by the flood [ 9 ]. Moreover, ant activity was not influenced by the flood and Gamasida are negatively affected by high ant activity [ 58 , 59 ]. Notably, three months after the flood, the density of Prostigmata was twice that in 2010.…”

Effects of biodiversity in agricultural landscapes on the protective microbiome of insects – a review

“…Ants can also help to maintain the health of an aphid colony by removing sticky honeydew that, if left, can encourage fungal growth (Buckley, ), and at least three aphid symbionts have been implicated in improving aphid resistance to fungi, including Regiella , Rickettsia , and Spiroplasma (Scarborough et al., ; Lukasik et al., ,b). Although plant species richness had no direct effect on ant abundance along a diversity gradient, soil temperature had a positive effect on ant abundance, and plant cover had a negative effect (Hertzog et al., ). As plant cover increases with plant species richness and soil temperature decreases with plant species richness, this suggests potential lower ant abundance and thus lower aphid attendance by ants at higher plant diversity.…”