scholarly journals Network complexity of rubber plantations is lower than tropical forests for soil bacteria but not fungi

2021 ◽  
Author(s):  
Guoyu Lan ◽  
Chuan Yang ◽  
Zhixiang Wu
Keyword(s):  
Network Structure ◽  
Tropical Rainforest ◽  
Soil Microbial Communities ◽  
Hainan Island ◽  
Past Research ◽  
Forest Conversion ◽  
Rubber Plantation ◽  
Microbial Composition ◽  
Rubber Plantations ◽  
Soil Microbial

Abstract. Soil microbial communities play a crucial role in ecosystem functioning. Past research has examined the effects of forest conversion on soil microbial composition and diversity, but it remains unknown how networks within these communities respond to forest conversion such as when tropical rainforest are replaced with rubber plantations. In this study, we used Illumina sequencing and metagenome shotgun sequencing to analyze bacterial and fungal community network structure in a large number of soil samples from tropical rainforest and rubber plantation sites in Hainan Island, China. Our results showed only a few shared network edges were observed in both bacterial and fungal communities, which indicates that forest conversion altered soil microbial network structure. We found a greater degree of network structure and a larger number of network edges among bacterial networks in samples from tropical rainforest compared to samples from rubber plantations. The difference was especially pronounced during the rainy season and indicates that rainforest bacterial networks were more complex than rubber plantation bacterial networks. However, rubber plantations soil fungal networks showed more higher links and higher network degree, suggesting that forest conversion does not reduce fungal network complexity. We found that some groups of Acidobacteria were keystone taxa in our tropical rainforest soils, while Actinobacteria were keystone taxa in rubber plantation soils. In addition, seasonal change had a strong effect on network degree, the complexity of soil bacterial and fungal network structure. In conclusion, forest conversion changed soil pH and other soil properties, such as available potassium (AK) and total nitrogen (TN), which resulted in changes in bacterial and fungal network composition and structure.

scholarly journals Effects of tropical rainforest conversion to rubber plantation on soil quality in Hainan Island, China

2021 ◽  
Author(s):  
Rui Sun ◽  
Guoyu Lan ◽  
Chuan Yang ◽  
Zhixiang Wu ◽  
Banqian Chen ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Properties ◽  
Soil Quality ◽  
Tropical Rainforest ◽  
Hainan Island ◽  
Tropical Rainforests ◽  
Forest Conversion ◽  
Rubber Plantation ◽  
Cellulose Decomposition ◽  
Rubber Plantations

Abstract. Land-use changes can alter soil properties and thus affect soil quality. Our understanding of how forest conversion (from tropical rainforest to rubber plantations) affects soil properties and soil quality is limited. An ideal testing ground for analyzing such land-use change and its impacts is Hainan Island, the largest tropical island in China. Based on 21 soil physicochemical and biological properties, a soil quality index (SQI) employed principal component analysis to assess soil quality changes from the conversion of tropical rainforests to rubber plantations. The results showed that (i) soil available potassium, available phosphorus, microbial biomass carbon, cellulose decomposition, acid phosphatase, and urease were vital soil properties for soil quality assessment on Hainan Island. (ii) The SQI of rubber plantations decreased by 26.48 % compared to tropical rainforests, while four investigated soil properties (soil pH, total phosphorus, cellulose decomposition, and actinomyces) increased. (iii) The SQI of both the tropical rainforests and rubber plantations showed significant spatial differences, which, under tropical rainforests, was more sensitive to seasonal changes than those under rubber plantations. (iv) Structural equation modeling suggested that forest conversion directly impacted soil quality and, indirectly impacted soil qualities' spatial variation by their interaction with soil types and geographical positions. Overall, though the conversion of tropical rainforest to rubber plantation did not decrease all soil properties, the tropical rainforest with its high soil quality should be protected.

scholarly journals Effects of forest conversion and seasonal changes on the assembly of bacterial and fungal communities in tropical forests

2021 ◽  
Author(s):  
G Lan ◽  
Bangqian Chen ◽  
Zhixiang Wu ◽  
Chuan Yang ◽  
Xicai Zhang
Keyword(s):  
Community Assembly ◽  
Bacterial Communities ◽  
Seasonal Changes ◽  
Rainy Season ◽  
Tropical Rainforest ◽  
Dry Season ◽  
Fungal Communities ◽  
Forest Conversion ◽  
Rubber Plantation ◽  
Soil Microbial

To date, few studies have assessed the impact of forest conversion or seasonal changes on soil microbial community assembly. To fill this research gap, 16S rRNA and ITS gene sequences were used to evaluate the effects of forest conversion and seasonal changes on the assembly of bacterial and fungal communities using 260 soil samples collected from tropical rainforest and rubber plantation sites across Hainan Island, South China. A majority (~60%) of observed OTUs conformed with neutral model expectations, indicating that neutral processes were important for the assembly of soil microbial communities. For bacterial communities, the NST (normalized stochasticity ratio) was higher in the tropical rainforest (0.746 in the dry season, 0.684 in the rainy season) versus rubber plantation sites (0.647, 0.584), regardless of season. Thus, forest conversion decreased the importance of stochasticity for soil bacterial community assembly. For fungal communities, rubber plantation communities showed greater stochasticity (NST = 0.578) than rainforest communities (NST = 0.388) in the dry season, but the reverse was true in the rainy season (NST = 0.852 for rubber plantations; NST = 0.978 for rainforest). Both the NST results and structural equation modeling showed that bacterial communities were more stochastic in the dry season, while fungal communities were more stochastic in the rainy season; the effects of seasonal changes on assembly therefore differed between bacterial and fungal communities. More importantly, forest conversion did not have a direct impact on the assembly of bacterial or fungal communities, but exerted indirect effects via soil pH and soil AK.

scholarly journals Dynamic Microbial Network Structure and Assembly Process in Rhizosphere and Bulk Soils Along a Coniferous Plantation Chronosequence

2021 ◽  
Author(s):  
Ying Wang ◽  
Liguo Dong ◽  
Min Zhang ◽  
Xiaoxiong Bai ◽  
Jiawen Zhang ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Fungal Community ◽  
Soil Microbial Communities ◽  
Dispersal Limitation ◽  
Soil Samples ◽  
Pinus Tabulaeformis ◽  
Bulk Soil ◽  
Microbial Composition ◽  
Soil Microbial ◽  
Plantation Development

Abstract Aims: During plantation development, microbial composition and diversity are critical for the establishment of plant diversity and multiple ecosystem functions. Here we aimed to evaluate the impacts of chronosequence and soil compartment on the bacterial and fungal community compositions, species co-occurrence, and assembly processes in forest ecosystem.Methods: Soils were collected in rhizosphere and bulk soils along a Pinus tabulaeformis plantation chronosequence (15, 30 and 60 years old). The bacterial and fungal communities were determined using amplicon sequencing.Results: The effect of stand age on the soil properties and microbial community structures was stronger than the effect of the soil compartment. In all soil samples, the dominant bacterial phyla were Proteobacteria, Acidobacteria, Actinobacteria, and Chloroflexi. Basidiomycota, Ascomycota, and Mortierellomycota were the dominant fungal phyla. Higher turnover rates of soil microbial communities were observed in rhizosphere soil than in bulk soil. Dispersal limitation governed the bacterial and fungal community assembly in all soil samples, and the fungal community was more susceptible to dispersal limitation. The bacterial and fungal keystone species compositions in the rhizosphere had significant positive correlations with the soil total phosphorus and nitrite nitrogen and total nitrogen and total phosphorus, respectively, indicating their importance in soil nitrogen and phosphorus cycling. The complexity of bacterial networks increased along the chronosequence. Fungal network complexity did not show a clear age-related trend but increased from bulk soil to the rhizosphere.Conclusions: During Pinus tabulaeformis plantation development, soil microbial assembly was less environmentally constrained due to an increase in resource availability.

scholarly journals Comparison of Soil Microbial Composition and Diversity Between Mixed and Monoculture Rubber Plantations in Hainan Province, China

2019 ◽  
Vol 12 ◽  
pp. 194008291987607 ◽  
Author(s):  
Muhammad Tahir Jatoi ◽  
Guoyu Lan ◽  
Zhixiang Wu ◽  
Rui Sun ◽  
Chuan Yang ◽  
...  
Keyword(s):  
Soil Ph ◽  
Hevea Brasiliensis ◽  
Fungal Communities ◽  
Rubber Plantation ◽  
Sequencing Analysis ◽  
Microbial Composition ◽  
Bacterial Composition ◽  
Rubber Plantations ◽  
Significant Difference ◽  
Soil Bacterial

This study aimed to compare monoculture and mixed rubber plantations in terms of their soil bacterial and fungal composition. An Illumina MiSeq sequencing analysis was performed to investigate the composition and diversity of the soil bacterial and fungal communities among three different rubber ( Hevea brasiliensis) plantations: monoculture, Mixed 1 ( Hevea brasiliensis and Mytilaria laosensis), and Mixed 2 ( Hevea brasiliensis and Michelia macclurei) in Hainan. The results showed that the bacterial composition of the three rubber plantations was basically similar. However, there was a significant difference in fungal communities among the three rubber plantations at both the phylum and operational taxonomic unit level. The species richness, Chao, and Shannon diversity of bacterial communities of monoculture rubber plantations were higher than the Mixed 1 and Mixed 2 rubber plantations, whereas all diversity indexes of fungal communities were relatively equal for the monoculture and mixed rubber plantations. Soil nutrition (such as total nitrogen and total potassium) and soil pH are the main drivers of the bacterial composition ( p <  .001). However, soil pH and water content are the main drivers of the fungal composition ( p <  .001), and to some extent, soil pH can increase soil bacteria diversity. We suggest that alkaline fertilizers should be applied in mixed rubber plantations to improve the soil pH and, consequently, to increase the total diversity of the rubber plantation.

scholarly journals Vulnerability and resistance in the spatial heterogeneity of soil microbial communities under resource additions

2020 ◽  
Vol 117 (13) ◽  
pp. 7263-7270 ◽  
Author(s):  
Kelly Gravuer ◽  
Anu Eskelinen ◽  
Joy B. Winbourne ◽  
Susan P. Harrison
Keyword(s):  
Spatial Variability ◽  
Spatial Heterogeneity ◽  
Soil Microbial Communities ◽  
Archaeal Community ◽  
Ecosystem Functions ◽  
Water Addition ◽  
Microbial Composition ◽  
Soil Microbial ◽  
The Face ◽  
And Function

Spatial heterogeneity in composition and function enables ecosystems to supply diverse services. For soil microbes and the ecosystem functions they catalyze, whether such heterogeneity can be maintained in the face of altered resource inputs is uncertain. In a 50-ha northern California grassland with a mosaic of plant communities generated by different soil types, we tested how spatial variability in microbial composition and function changed in response to nutrient and water addition. Fungal composition lost some of its spatial variability in response to nutrient addition, driven by decreases in mutualistic fungi and increases in antagonistic fungi that were strongest on the least fertile soils, where mutualists were initially most frequent and antagonists initially least frequent. Bacterial and archaeal community composition showed little change in their spatial variability with resource addition. Microbial functions related to nitrogen cycling showed increased spatial variability under nutrient, and sometimes water, additions, driven in part by accelerated nitrification on the initially more-fertile soils. Under anthropogenic changes such as eutrophication and altered rainfall, these findings illustrate the potential for significant changes in ecosystem-level spatial heterogeneity of microbial functions and communities.

scholarly journals Effects of forest conversion on soil microbial communities depend on soil layer on the eastern Tibetan Plateau of China

PLoS ONE ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. e0186053 ◽  
Author(s):  
Ruoyang He ◽  
Kaijun Yang ◽  
Zhijie Li ◽  
Martin Schädler ◽  
Wanqin Yang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Microbial Communities ◽  
Soil Layer ◽  
Soil Microbial Communities ◽  
Forest Conversion ◽  
Eastern Tibetan Plateau ◽  
Soil Microbial

scholarly journals Soil Bacterial and Fungal Composition and Diversity Responses to Seasonal Deer Grazing in a Subalpine Meadow

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 84
Author(s):  
Andéole Niyongabo Turatsinze ◽  
Baotian Kang ◽  
Tianqi Zhu ◽  
Fujiang Hou ◽  
Saman Bowatte
Keyword(s):  
Relative Abundance ◽  
Soil Microbial Communities ◽  
Gansu Province ◽  
Total Carbon ◽  
Mountain Range ◽  
Microbial Composition ◽  
Soil Microbial ◽  
Β Diversity ◽  
Α Diversity ◽  
Soil Bacterial

Soil microbial composition and diversity are widely recognized for their role in ecological functioning. This study examined the differences of soil microbial communities between two seasonally grazed grasslands. The study area was in the Gansu red deer farm located on the Qilian Mountain range in the Gansu province of northwestern China. This farm adopted a seasonal rotation grazing system whereby grasslands at higher altitudes are grazed in summer (SG), whilst grasslands at lower altitudes are grazed in winter (WG). The soil bacterial and fungal communities were examined by Illumina MiSeq sequencing. We found that soil water content (SWC), organic carbon (OC), total carbon (TC), and total nitrogen (TN) were significantly higher, whereas the C/N ratio was significantly lower in SG than WG pastures. The α-diversity of bacteria was greater than that of fungi in both pastures, while both bacterial and fungal α-diversity were not significantly different between the pastures. The bacterial β-diversity was significantly different between the pastures, but fungal β-diversity was not. The bacterial phylum Actinobacteria and fungal phylum Ascomycota were dominant in both pastures. The relative abundance of Actinobacteria in soil was significantly higher in WG pastures, whereas the relative abundance of Proteobacteria in soil was significantly higher in SG pastures. Significant correlations between bacterial and fungal phyla and soil properties were observed, but this varied between the two grasslands. This study showed that distinct microbial community structures developed in two pastures within the same geographic location that were grazed in different seasons.

Bushfire impacts on a threatened swamp ecosystem: responses of the soil microbial communities and restoration

2021 ◽  
Author(s):  
Nathali Machado de Lima ◽  
Alexandria Thomsen ◽  
Mark Ooi ◽  
Miriam Muñoz-Rojas
Keyword(s):  
Microbial Communities ◽  
Longwall Mining ◽  
Soil Microbial Communities ◽  
Environmental Indicators ◽  
Fire Season ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Drought Period ◽  
Soil Microbial ◽  
The Impact

&lt;p&gt;Australia faced the most extreme and prolonged fire season in 2019-2020, resulting in tragic habitat loss for many threatened species and the destruction of many ecological communities. &amp;#160;Newnes Plateau Shrub Swamps are peatlands located in the upper Blue Mountains region of New South Wales, Australia. These ecosystems perform many important ecological functions while absorbing and filtering water and releasing it slowly back to the environment. Their functions are related to the control of peak flow events, water purification and the harboring of many threatened plant and animal species. Despite their ecological importance, the area has been intensively degraded through longwall mining processes, resulting in the lowering and loss of water tables in the area. In December 2019 these impacts were compounded by an intense prolonged drought period and extensive wildfire. While the effects of these combined factors on the vegetation have been analysed and revealed remarkable negative impacts in the swamps under mining pressures, the effects on the soil microbial communities and related soil functions have not yet been studied. To investigate both drivers (fire and mining activities), we selected three mined swamps and three unmined swamps to assess their soil microbial composition and diversity through Next Generation Sequencing, and to characterise the soil chemical composition. At each site, we collected samples considering three treatments, one in the swamp valley fill and two at two different heights of the swamp valley margin, focusing on the soil close to specific groups of plants (e.g. sedges and shrubs). For each site and treatment, three soil samples (~ 10 m from each other) of 10x10 cm and ~ 3 to 5 cm of depth were collected using a trowel. We aim to build 16S rRNA gene libraries and co-relate them with the soil chemical variables, to assess the impact on these microbial communities and their possible use as environmental indicators and basis for future applied initiatives in conservation and restoration.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

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