Bacteria but not fungi respond to soil acidification rapidly and consistently in both a spruce and beech forest

2020 ◽  
Vol 96 (10) ◽  
Author(s):  
Michal Choma ◽  
Karolina Tahovská ◽  
Eva Kaštovská ◽  
Jiří Bárta ◽  
Michal Růžek ◽  
...  

ABSTRACT Anthropogenically enhanced atmospheric sulphur (S) and nitrogen (N) deposition has acidified and eutrophied forest ecosystems worldwide. However, both S and N mechanisms have an impact on microbial communities and the consequences for microbially driven soil functioning differ. We conducted a two-forest stand (Norway spruce and European beech) field experiment involving acidification (sulphuric acid addition) and N (ammonium nitrate) loading and their combination. For 4 years, we monitored separate responses of soil microbial communities to the treatments and investigated the relationship to changes in the activity of extracellular enzymes. We observed that acidification selected for acidotolerant and oligotrophic taxa of Acidobacteria and Actinobacteria decreased bacterial community richness and diversity in both stands in parallel, disregarding their original dissimilarities in soil chemistry and composition of microbial communities. The shifts in bacterial community influenced the stoichiometry and magnitude of enzymatic activity. The bacterial response to experimental N addition was much weaker, likely due to historically enhanced N availability. Fungi were not influenced by any treatment during 4-year manipulation. We suggest that in the onset of acidification when fungi remain irresponsive, bacterial reaction might govern the changes in soil enzymatic activity.

2020 ◽  
Vol 8 (11) ◽  
pp. 1828 ◽  
Author(s):  
Zongwei Xia ◽  
Jingyi Yang ◽  
Changpeng Sang ◽  
Xu Wang ◽  
Lifei Sun ◽  
...  

Increased soil nitrogen (N) from atmospheric N deposition could change microbial communities and functions. However, the underlying mechanisms and whether soil phosphorus (P) status are responsible for these changes still have not been well explained. Here, we investigated the effects of N and P additions on soil bacterial and fungal communities and predicted their functional compositions in a temperate forest. We found that N addition significantly decreased soil bacterial diversity in the organic (O) horizon, but tended to increase bacterial diversity in the mineral (A) horizon soil. P addition alone did not significantly change soil bacterial diversity but mitigated the negative effect of N addition on bacterial diversity in the O horizon. Neither N addition nor P addition significantly influenced soil fungal diversity. Changes in soil microbial community composition under N and P additions were mainly due to the shifts in soil pH and NO3− contents. N addition can affect bacterial functional potentials, such as ureolysis, N fixation, respiration, decomposition of organic matter processes, and fungal guilds, such as pathogen, saprotroph, and mycorrhizal fungi, by which more C probably was lost in O horizon soil under increased N deposition. However, P addition can alleviate or switch the effects of increased N deposition on the microbial functional potentials in O horizon soil and may even be a benefit for more C sequestration in A horizon soil. Our results highlight the different responses of microorganisms to N and P additions between O and A horizons and provides an important insight for predicting the changes in forest C storage status under increasing N deposition in the future.


2020 ◽  
Vol 8 (6) ◽  
pp. 834
Author(s):  
Naihui Li ◽  
Danmei Gao ◽  
Xingang Zhou ◽  
Shaocan Chen ◽  
Chunxia Li ◽  
...  

Intercropping can achieve sustainable agricultural development by increasing plant diversity. In this study, we investigated the effects of tomato monoculture and tomato/potato-onion intercropping systems on tomato seedling growth and changes of soil microbial communities in greenhouse conditions. Results showed that the intercropping with potato-onion increased tomato seedling biomass. Compared with monoculture system, the alpha diversity of soil bacterial and fungal communities, beta diversity and abundance of bacterial community were increased in the intercropping system. Nevertheless, the beta-diversity and abundance of fungal community had no difference between the intercropping and monoculture systems. The relative abundances of some taxa (i.e., Acidobacteria-Subgroup-6, Arthrobacter, Bacillus, Pseudomonas) and several OTUs with the potential to promote plant growth were increased, while the relative abundances of some potential plant pathogens (i.e., Cladosporium) were decreased in the intercropping system. Redundancy analysis indicated that bacterial community structure was significantly influenced by soil organic carbon and pH, the fungal community structure was related to changes in soil organic carbon and available phosphorus. Overall, our results suggested that the tomato/potato-onion intercropping system altered soil microbial communities and improved the soil environment, which may be the main factor in promoting tomato growth.


2020 ◽  
Author(s):  
Alejandro Atenas ◽  
Felipe Aburto ◽  
Rodrigo Hasbun ◽  
Carolina Merino

<p>Soil microorganism are an essential component of forest ecosystem. Microbes and plant release enzymes that catalyse reactions needed to decomposed soil organic matter and crucial to release nutrient in available forms. Therefore, soil enzymes are relevant indicators of microbial activity and nutrient cycling in forest ecosystems. Anthropic disturbances in natural forest, such as logging and exotic livestock, modify the structure and composition of forest thereby altering the structure and activities of soil microbial communities.</p><p>Here we determine the effect of these disturbances on the enzymatic activity (Dehydrogenase-DHA; Phosphatase Acid-AP; Ureasa-UA) and the microbial diversity using a forest degradation gradient of native temperate forest dominated by Nothofagus dombeyi, Nothofagus obliqua and Nothofagus alpina. In addition we quantify C:N:P nutrient reservoirs, stoichiometry and available pools. Preliminary results suggest a higher activity of the DHA enzyme in degraded forest dominated by N. obliqua. AP and UA showed no relationship with the phosphorus and total nitrogen reservoirs. Forest degradation modify microbial communities, C:N:P stoichiometry, total and available nutrient pools, where the biggest pool of total C and N was registered on low degraded condition and decrease as degradation condition increase from medium to high degraded forest (74.44%; 65.35%; 48.05% for total C and 3.71; 3.41; 3.24 for total N respectively). Inverse relation was registered for total P pool were the highest pool was registered on high degraded condition (14963ppm; 13092ppm and 11299ppm from high to low degraded condition). Degraded sites were dominated mainly by members of Gammaproteobacteria, Alfaproteobacteria, Acidobacteria and Bacteroidia. Chitinophagaceae and Burkholderiacea were not detected in degraded plots, which suggest that some of the specialised functions carried by this groups could be lost. With respect to fungi Ascomycota and Basidomicota Phylum dominated the soil profiles. A species of the genus Clonostachys (Bionectriaceae) was identified, an endophyte fungus that acts as a saprophyte, also known to be a parasite of other fungi and some nematodes.</p><p>This research contributes to a better understanding of the direct effects of anthropic disturbances on the biogeochemical functioning of temperate forests and their relationship to the activity and composition of microbial communities.</p><p>Acknowledgment: Proyecto Reforestación Enel – UdeC</p>


Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 161 ◽  
Author(s):  
Pan Wan ◽  
Gongqiao Zhang ◽  
Zhonghua Zhao ◽  
Yanbo Hu ◽  
Wenzhen Liu ◽  
...  

One of the aims of sustainable forest management is to preserve the diversity and resilience of ecosystems. Unfortunately, changes in the soil microbial communities after forest management remain unclear. We analyzed and compared the soil microbial community of a natural Quercus aliena var. acuteserrata forest after four years of four different management methods using high-throughput sequencing technology. The forest management methods were close-to-nature management (CNFM), structure-based forest management (SBFM), secondary forest comprehensive silviculture (SFCS) and unmanaged control (CK). The results showed that: (1) the soil microbial community diversity indices were not significantly different among the different management methods. (2) The relative abundance of Proteobacteria in the SBFM treatment was lower than in the CK treatment, while the relative abundance of Acidobacteria in the SBFM was significantly higher than that in the CK treatment. The relative abundance of Ascomycota was highest in the CNFM treatment, and that of Basidiomycota was lowest in the CNFM treatment. However, the relative abundance of dominant bacterial and fungal phyla was not significantly different in CK and SFCS. (3) Redundancy analysis (RDA) showed that the soil organic matter (SOM), total nitrogen (TN), and available nitrogen (AN) significantly correlated with the bacterial communities, and the available potassium (AK) was the only soil nutrient, which significantly correlated with the composition of the fungal communities. The short-term SBFM treatment altered microbial bacterial community compositions, which may be attributed to the phyla present (e.g., Proteobacteria and Acidobacteria), and the short-term CNFM treatment altered microbial fungal community compositions, which may be attributed to the phyla present (e.g., Ascomycota and Basidiomycota). Furthermore, soil nutrients could affect the dominant soil microbial communities, and its influence was greater on the bacterial community than on the fungal community.


2016 ◽  
Vol 7 ◽  
Author(s):  
Heiko Nacke ◽  
Kezia Goldmann ◽  
Ingo Schöning ◽  
Birgit Pfeiffer ◽  
Kristin Kaiser ◽  
...  

2012 ◽  
Vol 79 (4) ◽  
pp. 1284-1292 ◽  
Author(s):  
Kai Xue ◽  
Liyou Wu ◽  
Ye Deng ◽  
Zhili He ◽  
Joy Van Nostrand ◽  
...  

ABSTRACTVarious agriculture management practices may have distinct influences on soil microbial communities and their ecological functions. In this study, we utilized GeoChip, a high-throughput microarray-based technique containing approximately 28,000 probes for genes involved in nitrogen (N)/carbon (C)/sulfur (S)/phosphorus (P) cycles and other processes, to evaluate the potential functions of soil microbial communities under conventional (CT), low-input (LI), and organic (ORG) management systems at an agricultural research site in Michigan. Compared to CT, a high diversity of functional genes was observed in LI. The functional gene diversity in ORG did not differ significantly from that of either CT or LI. Abundances of genes encoding enzymes involved in C/N/P/S cycles were generally lower in CT than in LI or ORG, with the exceptions of genes in pathways for lignin degradation, methane generation/oxidation, and assimilatory N reduction, which all remained unchanged. Canonical correlation analysis showed that selected soil (bulk density, pH, cation exchange capacity, total C, C/N ratio, NO3−, NH4+, available phosphorus content, and available potassium content) and crop (seed and whole biomass) variables could explain 69.5% of the variation of soil microbial community composition. Also, significant correlations were observed between NO3−concentration and denitrification genes, NH4+concentration and ammonification genes, and N2O flux and denitrification genes, indicating a close linkage between soil N availability or process and associated functional genes.


Elem Sci Anth ◽  
2020 ◽  
Vol 8 ◽  
Author(s):  
Devan M. Nisson ◽  
Steven D. Allison

Many ecosystems are experiencing an increase in drought conditions as a consequence of climate warming and changing precipitation patterns. The stress imposed by these environmental changes can affect ecosystem processes such as the extracellular enzymatic degradation of carbon-containing leaf litter by soil microbial communities. However, the magnitude of these impacts may depend on the composition and metabolism of the microbial community. Based on the hypothesis of local adaptation, microbial communities native to warm-dry ecosystems should display a greater capacity to degrade leaf litter polymers with extracellular enzymes following exposure to warm-dry conditions. To test this hypothesis, we performed a microcosm study in which we monitored extracellular enzyme activity and respiration of microbial communities from five ecosystems along a southern California climate gradient, ranging from warmer, drier desert to wetter, cooler subalpine forest. To simulate drought and rewetting, we subjected microcosms to periods of high temperature and low moisture followed by a water pulse. We found that enzyme activity of wet-cool communities generally exceeded that of warm-dry communities across enzyme types for the five sites we considered. Additionally, we observed a significant decrease in respiration for all communities after longer durations of drought exposure. Although these findings did not align with our expectations of local adaptation, they suggest litter-inhabiting microbial communities are able to retain metabolic functioning in environmental conditions different from those of their native ecosystems. These results may imply that factors such as litter chemistry impose greater constraints than climate on community metabolic function. Overall, despite differences in local climates, microbial communities from semiarid regions may be metabolically adapted to maintain functioning in the face of drought.


Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 819 ◽  
Author(s):  
Jiajia Li ◽  
Lijuan Li ◽  
Muhammad Arif ◽  
Dongdong Ding ◽  
Xin Hu ◽  
...  

Plant and microbiome interactions are necessary for plant nutrient acquisition. However, relatively little is known about the responses of roots, bulk, and rhizosphere soil microbial communities in different artificial vegetation types (woody and herbaceous) in riparian areas of massive dams and reservoirs. Therefore, this study aims to assess such responses at elevations of 165–170 m a.s.l. in the riparian zones of the Three Gorges Dam Reservoir, China. The samples were collected containing the rhizosphere soil, bulk soil, and roots of herbaceous and woody vegetation at different emergence stages in 2018. Then, all the samples were analyzed to quantify the soil properties, bacterial community characteristics, and their interaction in the early and late emergence phases. In different periods, the weight of dominant soil bacteria, including Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, and Cyanobacteria, was higher, and their composition was different in the rhizosphere, bulk soil, and endophytes. Moreover, the soil co-occurrence networks indicated that the weight of soil physical properties was higher than chemical properties in the early emergence stage. In contrast, the weight of chemical properties was relatively higher in the late emergence stage. Furthermore, the richness and diversity of the bacterial community were mainly affected by soil organic matter. This study suggests that these herbaceous and woody vegetation are suitable for planting in reservoir areas affected by hydrology and human disturbance in light of soil nutrients and soil microbial communities, respectively. Additionally, these results provide valuable information to inoculate the soil with key microbiota members by applying fertilizers, potentially improving plant health and soil production.


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