Functional Diversity of the Soil Culturable Microbial Community in Eucalyptus Plantations of Different Ages in Guangxi, South China

Abstract

We selected five different ages of eucalyptus plantation sites to understand the culturable microbial functional diversity and the ecological functions of the soil from the eucalyptus plantations in Guangxi. We investigated the carbon source metabolic activity and diversity features of surface soil microbes using the Biolog EcoPlate method (Biolog Inc., Hayward, CA, USA), along with the microbial functional diversity and physicochemical properties of the soil. The results suggest that the carbon source utilization capacity of the soil microbes at various forest ages manifested as 3-year-old > 5-year-old > 2-year-old > 1-year-old > 8-year-old. The abundance, Shannon–Weiner, Pielou, Simpson, and McIntosh diversity indices of the soil microbes initially increased and then decreased with further increase in forest age, with the highest levels in 3- and 5-year-old forests. As per the heatmap analysis, the 3-year-old forest could metabolize the most carbon source species, while the 1- and 8-year-old forests could metabolize the least. Carbohydrates were the most frequently metabolized carbon source. The principal component analysis (PCA) shows that PC1 and PC2 extracted from the 31 factors have 52.42% and 13.39% of the variable variance, respectively. Carbohydrates contributed most to PCA, followed by amino acids and carboxylic acids, and phenolic acids and amines, the least. Canonical correspondence analysis shows that total carbon, alkali-hydrolyzable nitrogen, total nitrogen, total potassium, and pH negatively correlate with soil microbial functional diversity, whereas total and available phosphorus positively correlate with it. To sum up, the soil microbial community structure of eucalyptus plantations at various ages reflects the soil environmental conditions and nutrient availability, which is of great significance in the efficient management and high-quality operation of their plantations in Guangxi.

Exploring the Synergistic Impacts of Cover Crops and Fertilization on Soil Microbial Metabolic Diversity in Dryland Soybean Production Systems Using Biolog EcoPlates

“…AWCD is proportional to the number and species diversity of soil microbes that can metabolize carbon substrates, and it indicates the carbon source catabolic activity of microbial communities to utilize the carbon substrates [37,61]. In the present investigation, AWCD of soil microbial populations from cover crop and fertilizer source treatments exhibited classic microbial growth over time as the duration of incubation increased (Figure 1A,B), and these results were in accordance with other findings [40,53]. In this experiment, during the entire incubation period, native vegetation and cover crop mix (cereal rye + mustard) exhibited higher AWCD values than wheat, vetch, and cereal rye.…”

“…Studies have shown that mixed cover crops favor the release of certain allelochemicals, primary metabolites, and secondary metabolites significantly alter the soil microbial abundance and their functions [53]. However, cover crop biomass, quality, different soil types, C:N ratio of residues, environmental circumstances, and their interactions significantly influence the abundance and functional diversity of soil microbial populations [64].…”

“…In this formula, n i denotes the relative absorbance value in each ith well; N is the sum of the absorbance values of 31 wells [23]. The inverse Simpson diversity index (1/D) defines the species diversity by estimating the probability of one species encountering another [53].…”

Deciphering the microbial diversity associated with healthy and wilted Paeonia suffruticosa rhizosphere soil

“…Thus, both the soil microbial activity and metabolic ability of the diseased plants were higher than the healthy plants. The pathogenic invasion of these plants altered the microbial community structure, which consequently increased their carbon source utilization, and this reduced the bioavailability of nutrients in plants, thereby aggravating the disease ( Lan et al, 2019 ). In this study, the soil microbial metabolism enhancement may be related to the increase in specific microbial groups that can utilize carbohydrates and carboxylic acids.…”

Soil Hydrology Characteristics among Forest Type, Stand Age and Successive Rotation in Eucalyptus Plantations in Southern China

“…Eucalyptus, a rapidly growing tree species, has been extensively planted in southern China due to its economic value [3]; thus, it has become a dominant component of the timber plantations that have been established in the region over the past few decades [4,5]. Previous studies on Eucalyptus trees have primarily focused on their role as exotic species Forests 2024, 15, 423 2 of 14 in local ecosystems [6], exploring their impact on soil physicochemical properties [7], microbial community structure and function [8], and plant diversity [9]. These studies have provided insight into the effects of increasing Eucalyptus age on soil physicochemical properties, including stimulating enzyme activities such as phenol oxidase, peroxidase, and acid phosphatase [10].…”