Effects of experimental irrigation and drought on the composition and diversity of soil fauna in a coniferous stand

Abstract

Summary1. The effects of experimental long-term summer drought and irrigation on soil fauna were studied in a Norway spruce stand in south-western Sweden. The treatments, carried out over 8 and 10 years respectively, were chosen to simulate two scenarios of climate change, involving drier and wetter summers. 2. Different microarthropod communities developed in the different treatments. The abundances of enchytraeids, mesostigmatid mites and macroarthropod predators were all lowest in the drought plots. Drought decreased and irrigation increased the abundance and diversity of Oribatida. Drought decreased the abundance of Collembola. 3. The dominance structure of Oribatida and Collembola also changed, but less markedly. Drought affected community composition of both groups more than irrigation. 4. The study confirms that soil microarthropods can be useful environmental indicators, but their responses did not support the widely held view that deviations from a lognormal dominance structure indicates a stressed community. 5. The results also indicate that a drier climate with summer drought will lead to the local extinction of some soil animal species in this region.

The effects of heating, rhizosphere, and depth on root litter decomposition are mediated by soil moisture

“…This observation may be tied to greater soil moisture levels in unplanted plots leading to higher soil activity of the fauna responsible for comminution, or to differences in the microbial or macrofaunal communities in the planted and unplanted plots (e.g., Brandt et al 2006;Bird et al 2011;Shi et al 2015). Populations of soil macrofauna, which are key to litter comminution, can be reduced during dry conditions (Lindberg et al 2002).…”

Application of Oribatid Mites as Indicators (Review)

“…Additionally, biomass and diversity of fungi also decrease as an effect of draught and fungi present a food source for many Oribatid species. Moreover, oviposition of some species are connected to special fungi (Hågvar, 1998, Lindberg et al, 2002. Lindberg and Bengtsson (2005) described that there are differences among Oribatid groups in drought tolerance.…”

“…Besides, he pointed out that Oribatid mites are more sensitive and possess much moderate regeneration ability compared to Collembola or Mesostigmata (Lindberg and Bengtsson, 2006). Lindberg et al (2002 and2006) listed several supposed causes of high susceptibility: in some lifestages Oribatid mites are very sensitive to drought, larger species can not wander deeper into the soil, so they have an inferior dispersion ability. Additionally, biomass and diversity of fungi also decrease as an effect of draught and fungi present a food source for many Oribatid species.…”

“…This study also pointed out that if a soil sample from a humid site was placed into the soil in an arid area, only the abundance of the Oribatid group decreased, which can be considered as a further proof of this group's drought susceptibility. Lindberg et al (2002) conducted extensive studies in Swedish coniferous forests concerning drought effects. He also pointed out that long-term deprivation of precipitation decreases the abundance of Oribatid mites and the diversity of the community (Lindberg et al, 2002).…”

“…Lindberg et al (2002) conducted extensive studies in Swedish coniferous forests concerning drought effects. He also pointed out that long-term deprivation of precipitation decreases the abundance of Oribatid mites and the diversity of the community (Lindberg et al, 2002). Lindberg also examined what kind of long-lasting effects have been caused by draught to the community and how long the regeneration would take: he could not measure similar results even three years after the intervention comparing treated and untreated control sites.…”