Response of soil microbial community structure to increased precipitation and nitrogen addition in a semiarid meadow steppe

Abstract

Additions of nitrogen (N) and water might have an interactive effect on the structure of the soil microbial community. The effects and importance of a fluctuating natural precipitation regime on the soil microbial community in a semiarid meadow steppe are very variable and less well known. On a Stipa baicalensis Rosh. meadow steppe, we used phospholipid fatty acid (PLFA) analysis to evaluate the effects of increased precipitation, addition of nitrogen and precipitation regime in regulating the structure of the microbial community. The experiment had a complete randomized block design with additions of N of 0, 5 and 10 g N m−2 year−1 and of water of 15 or 30% above the natural precipitation from 2010 to 2012. Additional water and number of years had interactive effects on the soil's microbial community structure. The indirect effects of water and N on soil properties such as pH might explain, at least in part, the changes in microbial groups. Additional water significantly decreased PLFAs for most microbial groups in the dry year, but had no effect in the wet year. The results reflected fluctuation in the natural precipitation regime during two hydrologically contrasting years. Changes in the structure of the soil microbial community might depend on variation in interannual precipitation on meadow steppe. Overall, this study emphasizes the importance of the precipitation regime for the soil's microbial community structure. Increases in natural precipitation will weaken the negative effects of nitrogen fertilizers on the grassland ecosystem in future. Highlights Effects of fluctuating natural precipitation and additions of nitrogen on soil's microbial community structure. Structure of soil's microbial community might depend on variation in interannual precipitation on meadow steppe. Increases in natural precipitation weaken the negative effects of nitrogen fertilizers on the grassland ecosystem. Precipitation regime has an important effect on soil's microbial community structure.

The Effect of Forest Thinning on Soil Microbial Community Structure and Function

“…Soil water content and soil pH were the key factors to regulate soil microbial community structure, function, and soil carbon process [54]. The result showed that thinning treatment increased soil water content.…”

“…It was suggested that there were strong correlations between soil pH and microbial community to control soil carbon turnover. The previous study theorized that soil physicochemical properties and microbiological diversity contributed to carbon turnover and transformation [54]. After thinning treatment, the variation in soil pH and soil water content influenced soil microbial function relating to carbon decomposition, which was regulated by soil microbial community structure, and finally affected soil carbon properties.…”

Effects of Simulated Nitrogen Deposition and Precipitation Manipulation on Soil Microorganisms in the Desert Steppe of Northern China

“…Bi et al (2012) reported the interactive effects of water and N addition on gram negative/gram positive bacteria and the ratio of fungal to bacterial PLFA in a semiarid steppe. In addition, the response of microbial communities to precipitation changes and N deposition may depend on the inter-annual variation of the climate (Sun et al, 2014), variation in inter-annual precipitation (Sun et al, 2017), and vegetation type (Khalili et al, 2016).…”

Effect of coupled reduced irrigation and nitrogen fertilizer on soil mite community composition in a wheat field

“…Although many studies had been conducted to evaluate the effects of water and nitrogen fertilizer addition on soil organism community, many variations and inconsistencies can be found in the literature (Melguizo-Ruiz et al, 2017;Sun et al, 2017). Although many studies had been conducted to evaluate the effects of water and nitrogen fertilizer addition on soil organism community, many variations and inconsistencies can be found in the literature (Melguizo-Ruiz et al, 2017;Sun et al, 2017).…”

“…Changes in water and nitrogen fertilizer addition may affect soil organism communities through different mechanisms. Although many studies had been conducted to evaluate the effects of water and nitrogen fertilizer addition on soil organism community, many variations and inconsistencies can be found in the literature (Melguizo-Ruiz et al, 2017;Sun et al, 2017). For example, elevated water addition increased soil fungi and decreased soil bacteria, while increased nitrogen fertilizer addition had the opposite effects because water addition led to significant changes in soil characteristics (Ma et al, 2016).…”