Deciphering belowground nitrifier assemblages with elevational soil sampling in a subtropical forest ecosystem (Mount Lu, China)

Abstract

The elevational distribution patterns of microbial functional groups have long been attracting scientific interest. Ammonia-oxidizers (ammonia-oxidizing archaea [AOA] and bacteria [AOB]), complete ammonia oxidation (comammox) Nitrospira and nitrite-oxidizers (e.g. Nitrobacter and Nitrospira) play crucial roles in the nitrogen cycle, yet their activities and abundances in response to elevational gradients in a subtropical forest ecosystem remain unclear. Here, we investigated the distribution of potential functions and abundances of these nitrifiers in forest soils along elevational gradients on Mount Lu, China. Our results showed that AOA and Nitrospira abundance was higher than that of their counterparts. Only AOA, Nitrobacter and comammox Nitrospira abundances followed a hump-backed-model with altitude. Soil potential ammonia-oxidation activity (PAO) and nitrite-oxidation activity (PNO) ranged from 0.003 to 0.084 and 0.34 to 0.53 μg NO2−-N g−1 dry soil h−1, respectively. The biotic (AOA, Nitrobacter, Nitrospira and comammox Nitrospira abundances) and abiotic factors (soil variables) jointly affected PAO, whereas the abiotic factors were mainly responsible for PNO. Variance partitioning analysis showed that contemporary environmental disturbance is the most important driver for the biogeography of nitrifier assemblages. Overall, our findings indicate that forest soil nitrifier assemblages exhibit a biogeographic pattern largely shaped by soil chemistry along an elevational gradient.

Bacterial rather than fungal diversity and community assembly drive soil multifunctionality in a subtropical forest ecosystem

“…Soil‐dwelling microorganisms are highly diverse and generally play an important role in governing and regulating various ecosystem functions (Zavaleta et al ., 2010; Byrnes et al ., 2014; Jing et al ., 2015; Lefcheck et al ., 2015; Delgado‐Baquerizo et al ., 2017; Han et al ., 2018; Han et al ., 2021a), such as climate change, carbon and nitrogen cycling, biomass production and plant residue decomposition. Traditionally, many studies have focused mainly on the impact of diversity on a single ecosystem function (e.g., plant productivity, biomass, soil extracellular enzyme activity and/or nutrition cycling) (Cardinale et al ., 2011; Isbell et al ., 2011; Bardgett and Van der Putten, 2014; Wagg et al ., 2014; Han et al ., 2020). However, the lack of a comprehensive investigation on the function of the overall ecosystem may lead to a limited understanding of how soil microbial diversity influences ecosystem functions (Soliveres et al ., 2016).…”

Distribution, Diversity, and Abundance of Nitrite Oxidizing Bacteria in the Subterranean Estuary of the Daya Bay

“…Nitrite oxidizing bacteria includes seven effectively recognized genera (Daims et al, 2016). Among these NOB genera, Nitrospira belongs to phylum Nitrospirae (Ehrich et al, 1995), which forms an independent branch in phylogenetic analysis, and is considered to be the most diverse and ubiquitous in natural and engineered ecosystems (Fujitani et al, 2013;Park et al, 2017), such as soils, marine sponge, geothermal spring, acid mine drainage, estuary, and subtropical forest (Bartosch et al, 2002;Off et al, 2010;Lebedeva et al, 2011;Ramanathan et al, 2017;Hou et al, 2018;Han et al, 2020). In addition, Nitrospira may be involved in soil nitrification more actively than Nitrobacter by DNA-stable isotope probing (SIP) investigation (Xia et al, 2011).…”

“…In addition, Nitrospira may be involved in soil nitrification more actively than Nitrobacter by DNA-stable isotope probing (SIP) investigation (Xia et al, 2011). These results suggest Nitrospira plays a predominant role in the nitrite oxidation process and ecological balance in natural ecosystems (Han et al, 2021). However, the community structure and diversity distribution characteristics of Nitrospira are still limited in the STE.…”