Temperature‐ and moisture‐induced changes in the structure of the nematode fauna of a semiarid grassland –‐ patterns and mechanisms

Abstract

Summary A field experiment was established to examine the effects of temperature and moisture modifications on the nematode fauna of a semiarid grassland. Several combinations of drying, wetting, warming and cooling were applied to plots and compared with untreated control plots. The experiment was performed from July to October 1996. A significant shift was observed in the structure of the nematode fauna between late summer and early autumn. This shift was manifested in the disappearance of four rare genera; Ecumenicus, Eucephalobus, Paraphelenchus and Pungentus. A significant decrease was found in the density of Acrobeles, Aphelenchoides, Ditylenchus and Prismatolaimus; in addition there was a significant increase in the density of Cephalobus, Helicotylenchus, Paratylenchus and Tylenchorhynchus. Community structural change was represented by an initial decrease in nematode generic richness of 30–50%, and in a statistically significant decrease of nematode diversity in the control and all treated plots. Thereafter, emergence of a new community was demonstrated. Data show that temperature manipulation was the main factor to influence nematode diversity, Maturity Index, and Plant Parasite Index. However, nematode population density was influenced predominantly by the soil moisture content. Coenological analysis of soil nematode fauna appears to be a useful tool for the biological monitoring of the effects of global change on semiarid grasslands.

Towards multi-level biomonitoring of nematodes to assess risk of nitrogen and phosphorus pollution in Jinchuan Wetland of Northeast China

“…Our results also supported the findings of Neher et al (2005), who reported that Acrobeloides, Protorhabditis, Eumonhystera, and Wilsonema were relative to soil pH. We also found Aphelenchoides in high abundance in the wet conditions at the edge of the wetland, which is consistent with the field study by Bakonyi and Nagy (2000), which found that moisture had no effect on Acrobeles and Acrobeloides. Another study found that Acrobeloides had a growing abundance under dry conditions and variable water conditions (Griffiths et al 2003).…”

A meta-analysis of responses of soil biota to global change

“…There were no warming studies in our dataset in which authors defined the feeding preferences of measured organisms, but there were nine measurements of mites and nematodes in CO 2 enrichment studies with defined trophic groups for different species (Klironomos et al 1997;Yeates et al 1997;Hoeksema et al 2000;Hungate et al 2000;Niklaus et al 2003;Neher et al 2004;Sonnemann and Wolters 2005) and six measurements of nematodes and macroarthropods in precipitation studies (Freckman et al 1987;Todd et al 1999;Bakonyi and Nagy 2000;Lindberg et al 2002;Lindberg and Persson 2004). The dataset was expanded to incorporate these means and errors for different trophic groups (Online resource 4; Online resource 5).…”

Seasonal fluctuations of the nematode communities in a hop garden soil

“…Neher et al … (2004) stated that fluctuation of nematodes during vegetation is influenced by several biotic and abiotic factors such as temperature, annual rainfall, type of soil and plants, organic substances, microflora and management practices. As reported by Bakonyi and Nagy (2000), temperature is the main factor influencing nematode diversity although the nematode abundance is predominantly affected by the soil moisture content. In Slovakia the structure of nematode communities in hop gardens was studied only during a single season (2004) (Lišková & Renčo, 2007), whereas information on the seasonal fluctuation of nematodes in a longer period is lacking.…”