scholarly journals Historical land use has long-term effects on microbial community assembly processes in forest soils

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Ernest D. Osburn ◽  
Frank O. Aylward ◽  
J. E. Barrett

AbstractLand use change has long-term effects on the structure of soil microbial communities, but the specific community assembly processes underlying these effects have not been identified. To investigate effects of historical land use on microbial community assembly, we sampled soils from several currently forested watersheds representing different historical land management regimes (e.g., undisturbed reference, logged, converted to agriculture). We characterized bacterial and fungal communities using amplicon sequencing and used a null model approach to quantify the relative importance of selection, dispersal, and drift processes on bacterial and fungal community assembly. We found that bacterial communities were structured by both selection and neutral (i.e., dispersal and drift) processes, while fungal communities were structured primarily by neutral processes. For both bacterial and fungal communities, selection was more important in historically disturbed soils compared with adjacent undisturbed sites, while dispersal processes were more important in undisturbed soils. Variation partitioning identified the drivers of selection to be changes in vegetation communities and soil properties (i.e., soil N availability) that occur following forest disturbance. Overall, this study casts new light on the effects of historical land use on soil microbial communities by identifying specific environmental factors that drive changes in community assembly.

Soil Research ◽  
2019 ◽  
Vol 57 (3) ◽  
pp. 228
Author(s):  
C. Celestina ◽  
P. W. G. Sale ◽  
J. R. Hunt ◽  
C. Tang ◽  
A. E. Franks

A large-scale field experiment was used to investigate the long-term effects of a single application of manure or inorganic fertiliser on microbial communities in the topsoil and subsoil of a cropping field in south-west Victoria. Poultry litter (20 t ha–1) and fertiliser (with equivalent total nutrients to the manure) was either surface broadcast or deep ripped into the subsoil before sowing in 2014. Soil samples were collected from the 0–10 and 25–40cm horizons in each treatment immediately after harvest of the third successive crop in January 2017. Next-generation sequencing of the 16S and ITS rRNA genes was used to characterise the bacterial and fungal communities in the soil. Amendment type and method of placement had a limited effect on soil microbial community structure and diversity, three years after treatments were applied. Fungal communities exhibited weak responses to the poultry litter and fertiliser in comparison to a nil control, but none of the treatments had any detectable effect on bacterial communities. Differences in structure and diversity of microbial communities were overwhelmingly due to their vertical distribution in the soil profile, and not the application of different amendments to the soil by deep ripping or surface broadcasting. The strength and timing of the soil disturbance, plant selection effects and farm management history likely contributed to the lack of measurable response in the soil microbial community.


Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 978
Author(s):  
Ma ◽  
Zou ◽  
Yang ◽  
Hogan ◽  
Xu ◽  
...  

Understanding the ecological processes that regulate microbial community assembly in different habitats is critical to predict microbial responses to anthropogenic disturbances and environmental changes. Rubber (Hevea brasiliensis) and Eucalypt (Eucalyptus urophylla) plantations (thereafter RP and EP) are rapidly established at the expense of forests in tropical China, greatly affecting tropical soils and their processes. However, the assembly processes of soil microbial communities after forest conversions remain unclear. We investigated soil microbial communities’ attributes and quantified the portion of deterministic assembly variation in two RP (a 3- and a 5-year-old) and two EP (a 2- and a 4-year-old) in Southern China. Shannon and Faith’s Phylogenetic α-diversity of both bacterial and fungal communities were higher in RP than in EP, regardless of plantation age or soil depth (0–50 cm). Bacterial and fungal community structure was significantly different among the four plantations. The dominant microbial taxa in RP closely tracked the availability of nitrogen, phosphorus and potassium (K) while those in EP were closely related to the high total K content. Microbial co-occurrence networks in RP were more modular than those in EP, as governed by more keystone taxa that were strongly dependent on soil available nutrients. Environmental filtering imposed by soil nutrients heterogeneity contributed a considerable portion (33–47%) of bacterial assembly variation in RP, but much less (8–14%) in EP. The relative contribution of environmental selection on fungal assembly was also greater in RP than in EP. Our findings suggest that in RP clear microbial community patterns exist with respect to soil nutrients, whereas in EP microbial community assembly patterns are more stochastic and variable. The large variation in soil microbial community assembly patterns in EP could lead to fragile and unstable microbial-soil relationships, which may be one factor driving soil degradation in EP.


2021 ◽  
Author(s):  
Wan Tao ◽  
Rui Xu ◽  
Hanzhi Lin ◽  
Duanyi Huang ◽  
Pingzhou Su ◽  
...  

Abstract The extensive application of perfluoroalkyl and polyfluoroalkyl substances (PFASs) causes their frequent detection in various environments. Nevertheless, the effects of PFASs exposure on environmental microorganisms still remain unknown. In current work, two typical PFASs, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are selected to investigate their long-term effects on soil microbes. Microbial community structure and diversity were investigated by high-throughput sequencing and multiple statistical methods. Under 90-days of exposure, PFAS treatments increased the alpha-diversity of soil microbial communities with PFOS treatment, followed by PFOA treatment. The long-term exposure of PFASs substantially changed the compositions of soil microbial communities. The most abundant phylum Proteobacteria decreased from 82.9% (without amended PFASs) to 62.1% (with PFOA treatment) and 77.8% (with PFOS treatment). As a comparison, the relative abundance of Bacteroidetes, Chloroflexi, Acidobacteria, and Ignavibacteriae increased in the PFOA or PFOS groups. Comparative co-occurrence networks were constructed to investigate the biotic interactions in the two treatments. It was found that most taxonomy nodes in the PFOA and PFOS networks were associated with the genus Hydrogenophaga and Pseudoxanthomonas, respectively. The LEfSe analysis identified a set of core taxonomies (e.g., Azospirillum, Methyloversatilis, Ancylobacter, Hydrogenophaga, and Methylomonas) in the soil microbial communities and suggested their different preferences to PFAS exposures. Functional gene prediction suggested that the microbial metabolism processes, such as nucleotide transport and metabolism, cell motility, carbohydrate transport and metabolism, energy production and conversion, and secondary metabolites biosynthesis transport and catabolism, might be significantly inhibited under PFAS exposure, which may further affect soil ecological services.


2017 ◽  
Vol 93 (10) ◽  
Author(s):  
Dennis Goss-Souza ◽  
Lucas William Mendes ◽  
Clovis Daniel Borges ◽  
Dilmar Baretta ◽  
Siu Mui Tsai ◽  
...  

2021 ◽  
Author(s):  
Alin Song ◽  
Zimin Li ◽  
Fenliang Fan

<p>Returning crop straw into soil is an important practice to balance biogenic and bioavailable silicon (Si) pool in paddy, which is crucial for rice healthy growth. However, it remains elusive how straw return affects Si bioavailability, its uptake, and rice yield, owing to little knowledge about soil microbial communities responsible for straw degradation. Here, we investigated the change of soil Si fractions and microbial community in a 39-year-old paddy field amended by a long-term straw return. Results showed that rice straw-return significantly increased soil bioavailable Si and rice yield to from 29.9% to 61.6% and from 14.5% to 23.6%, respectively, compared to NPK fertilization alone. Straw return significantly altered soil microbial community abundance. Acidobacteria was positively and significantly related to amorphous Si, while Rokubacteria at the phylum level, Deltaproteobacteria and Holophagae at the class level were negatively and significantly related to organic matter adsorbed and Fe/Mn-oxide combined Si in soils. Redundancy analysis of their correlations further demonstrated that Si status significantly explained 12% of soil bacterial community variation. These findings suggest that soil bacteria community and diversity interact with Si mobility via altering its transformation, resulting in the balance of various nutrient sources to drive biological silicon cycle in agroecosystem.</p>


Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 285 ◽  
Author(s):  
Mengxin Zhao ◽  
Jing Cong ◽  
Jingmin Cheng ◽  
Qi Qi ◽  
Yuyu Sheng ◽  
...  

Subtropical and tropical broadleaf forests play important roles in conserving biodiversity and regulating global carbon cycle. Nonetheless, knowledge about soil microbial diversity, community composition, turnover and microbial functional structure in sub- and tropical broadleaf forests is scarce. In this study, high-throughput sequencing was used to profile soil microbial community composition, and a micro-array GeoChip 5.0 was used to profile microbial functional gene distribution in four sub- and tropical broadleaf forests (HS, MES, HP and JFL) in southern China. The results showed that soil microbial community compositions differed dramatically among all of four forests. Soil microbial diversities in JFL were the lowest (5.81–5.99) and significantly different from those in the other three forests (6.22–6.39). Furthermore, microbial functional gene interactions were the most complex and closest, likely in reflection to stress associated with the lowest nitrogen and phosphorus contents in JFL. In support of the importance of environmental selection, we found selection (78–96%) dominated microbial community assembly, which was verified by partial Mantel tests showing significant correlations between soil phosphorus and nitrogen content and microbial community composition. Taken together, these results indicate that nitrogen and phosphorus are pivotal in shaping soil microbial communities in sub- and tropical broadleaf forests in southern China. Changes in soil nitrogen and phosphorus, in response to plant growth and decomposition, will therefore have significant changes in both microbial community assembly and interaction.


2011 ◽  
Vol 62 (2) ◽  
pp. 474-485 ◽  
Author(s):  
Bo Sun ◽  
Zhi-Xing Dong ◽  
Xue-Xian Zhang ◽  
Yun Li ◽  
Hui Cao ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6746 ◽  
Author(s):  
Pengyu Zhao ◽  
Jiabing Bao ◽  
Xue Wang ◽  
Yi Liu ◽  
Cui Li ◽  
...  

Microbial community assembly is influenced by a continuum (actually the trade-off) between deterministic and stochastic processes. An understanding of this ecological continuum is of great significance for drawing inferences about the effects of community assembly processes on microbial community structure and function. Here, we investigated the driving forces of soil microbial community assembly in three different environmental contexts located on subalpine coniferous forests of the Loess Plateau in Shanxi, China. The variation in null deviations and phylogenetic analysis showed that a continuum existed between deterministic and stochastic processes in shaping the microbial community structure, but deterministic processes prevailed. By integrating the results of redundancy analysis (RDA), multiple regression tree (MRT) analysis and correlation analysis, we found that soil organic carbon (SOC) was the main driver of the community structure and diversity patterns. In addition, we also found that SOC had a great influence on the community assembly processes. In conclusion, our results show that deterministic processes always dominated assembly processes in shaping bacterial community structure along the three habitat contexts.


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