High Ammonium Addition Changes the Diversity and Structure of Bacterial Communities in Temperate Wetland Soils of Northeastern China

Abstract

The soil microbiome is an important component of wetland ecosystems and plays a pivotal role in nutrient cycling and climate regulation. Nitrogen (N) addition influences the soil’s microbial diversity, composition, and function by affecting the soil’s nutrient status. The change in soil bacterial diversity and composition in temperate wetland ecosystems in response to high ammonium nitrogen additions remains unclear. In this study, we used high-throughput sequencing technology to study the changes of soil bacterial diversity and community structure with increasing ammonium concentrations [CK (control, 0 kg ha−1 a−1), LN (low nitrogen addition, 40 kg ha−1 a−1), and HN (high nitrogen addition, 80 kg ha−1 a−1)] at a field experimental site in the Sanjiang Plain wetland, China. Our results showed that except for soil organic carbon (SOC), other soil physicochemical parameters, i.e., soil moisture content (SMC), dissolved organic nitrogen (DON), total nitrogen (TN), pH, ammonium nitrogen (NH4+), and dissolved organic carbon (DOC), changed significantly among three ammonium nitrogen addition concentrations (p < 0.05). Compared to CK, LN did not change soil bacterial α-diversity (p > 0.05), and HN only decreased the Shannon (p < 0.05) and did not change the Chao (p > 0.05) indices of soil bacterial community. Ammonium nitrogen addition did not significantly affect the soil’s bacterial community structure based on non-metric multidimensional scaling (NMDS) and PERMANOVA (ADONIS) analyses. Acidobacteriota (24.96–31.11%), Proteobacteria (16.82–26.78%), Chloroflexi (10.34–18.09%), Verrucomicrobiota (5.23–11.56%), and Actinobacteriota (5.63–8.75%) were the most abundant bacterial phyla in the soils. Nitrogen addition changed the complexity and stability of the bacterial network. SMC, NO3−, and pH were the main drivers of the bacterial community structure. These findings indicate that enhanced atmospheric nitrogen addition may have an impact on bacterial communities in soil, and this study will allow us to better understand the response of the soil microbiome in wetland ecosystems in the framework of increasing nitrogen deposition.

The Diversity and Composition of Soil Microbial Communities Differ in Three Land Use Types of the Sanjiang Plain, Northeastern China

“…Soil organic carbon (SOC) was determined using an elemental analyzer (VarioEL III, Langenselbold, Germany) [24]. Briefly, twenty-five mL of 0.3 mol/L KMnO 4 solution was added to 0.5 g of soil, shaken for 30 min at room temperature, then centrifuged (5000 r/min) for 5 min, and the supernatant was diluted 250-fold with distilled water, and the absorbance at 565 nm was determined spectrophotometrically.…”

pH-Related Changes in Soil Bacterial Communities in the Sanjiang Plain, Northeast China

“…Soil total nitrogen (TN) was determined by an elemental analyzer (VarioEL III, Langenselbold, Germany) [43,44]; Soil ammonium nitrogen (NH 4 + N) content was measured using a continuous flow analysis system (SKALAR SAN++, Breda, The Netherlands) [45]. Soil organic carbon (SOC) was determined using an elemental analyzer (VarioEL III, Langenselbold, Germany) [46].…”

Interruption after Short-Term Nitrogen Additions Improves Ecological Stability of Larix olgensis Forest Soil by Affecting Bacterial Communities

“…Compared with fungi, bacteria have small size, rapid reproduction and renewal, strong metabolic ability, and high sensitivity to changes in foreign substances, so they are more responsive to changes in the external environment [13]. Previous studies have recognized that N addition affects the structure, composition, and diversity of microbial communities, resulting in positive, negative, or no-impact outcomes [14,15]. Most of these studies have confirmed that N addition alters soil nutrition condition and accelerates soil acidification, thereby reducing the diversity of soil microorganisms, and ultimately destroys the ecosystem function of the forest ecosystem [16,17].…”