Microbial community structure and the relationship with soil carbon and nitrogen in an original Korean pine forest of Changbai Mountain, China

Abstract

Background The broad-leaved Korean pine mixed forest is an important and typical component of a global temperate forest. Soil microbes are the main driver of biogeochemical cycling in this forest ecosystem and have complex interactions with carbon (C) and nitrogen (N) components in the soil. Results We investigated the vertical soil microbial community structure in a primary Korean pine-broadleaved mixed forest in Changbai Mountain (from 699 to 1177 m) and analyzed the relationship between the microbial community and both C and N components in the soil. The results showed that the total phospholipid fatty acid (PLFA) of soil microbes and Gram-negative bacteria (G-), Gram-positive bacteria (G+), fungi (F), arbuscular mycorrhizal fungi (AMF), and Actinomycetes varied significantly (p < 0.05) at different sites (elevations). The ratio of fungal PLFAs to bacterial PLFAs (F/B) was higher at site H1, and H2. The relationship between microbial community composition and geographic distance did not show a distance-decay pattern. The coefficients of variation for bacteria were maximum among different sites (elevations). Total soil organic carbon (TOC), total nitrogen (TN), soil water content (W), and the ratio of breast-height basal area of coniferous trees to that of broad-leaved tree species (RBA) were the main contributors to the variation observed in each subgroup of microbial PLFAs. The structure equation model showed that TOC had a significant direct effect on bacterial biomass and an indirect effect upon bacterial and fungal biomass via soil readily oxidized organic carbon (ROC). No significant relationship was observed between soil N fraction and the biomass of fungi and bacteria. Conclusion The total PLFAs (tPLFA) and PLFAs of soil microbes, including G-, G+, F, AMF, and Actinomycetes, were significantly affected by elevation. Bacteria were more sensitive to changes in elevation than other microbes. Environmental heterogeneity was the main factor affecting the geographical distribution pattern of microbial community structure. TOC, TN, W and RBA were the main driving factors for the change in soil microbial biomass. C fraction was the main factor affecting the biomass of fungi and bacteria and ROC was one of the main sources of the microbial-derived C pool.

Impact of Land Use on Bacterial Diversity and Community Structure in Temperate Pine and Indigenous Forest Soils

“…Previous studies have stated that total carbon is a key factor influencing the structure of soil microbial communities. Total carbon has been reported to have substantial direct influence on soil bacterial biomass and it could afford bacteria the benefit of competition with fungal communities for resources [39][40][41]. Phosphorus also affected the structure of the bacterial communities in this study.…”

Impact assessment of textile effluent on health and microbiota of agricultural soil in Bhagwanpur (Uttarakhand), India

“…Highly concentrated metals in soil show inhibitory effects on the microorganisms due to dysfunctional microbial processes such as decomposition, and soil respiration [54]. The decrease in microbial count could also be linked with decrease in the concentration of organic carbon required for sustaining microbial growth [55]. However, no specific trend was observed for microbial count at different sites.…”

Effects of Field-Grown Transgenic Cry1Ah1 Poplar on the Rhizosphere Microbiome

“…Soil microbial biomass is an essential biological fertility index used to evaluate soil quality [59,60]. Nitrogen and phosphorus de ciency generally have adverse effects on soil microbial reproduction and metabolic activity, as well as on crop growth and nutrient uptake [27,61,62]. The lower MBN and MBP contents in Cry1Ah1-modi ed poplars suggested that soil microorganisms were under nutrient de ciency stress due to low metabolic e ciency and more signi cant release of heat and CO 2 during metabolism, signi cantly reducing soil quality.…”

“…Soil microorganisms are an essential part of the soil ecosystem and are involved in various biochemical processes, including organic matter accumulation and mineralization, as well as nutrient transformation and circulation [23,24]. GM plants communicate with soil microorganisms during the growth process; therefore, research on the potential effects of GM plants on the soil microbial community is of great signi cance in evaluating their potential risks [25][26][27]. The purpose of this study was to identify the effects of Bt-modi ed poplar plantation on soil chemical properties, as well as the diversity and structure of the soil microorganism community after four years of growth under eld conditions.…”