Replacement of native vegetation alters the soil microbial structure in the Pampa biome

Abstract

Land use change is one of the the major factors related to soil degradation and alterations in soil microbial diversity and structure. In this study, we aimed to evaluate the microbial shifts caused by deforestation of a small area of a natural forest for the introduction of a pasture in the Brazilian Pampa. The microbial abundance and structure were evaluated by molecular approaches based on quantitative Polymerase Chain Reaction (qPCR) and Ribosomal Intergenic Spacer Analysis (RISA). The microbial communities did not present significant quantitative differences, but the environmental impact caused by deforestation changed the structure of the bacterial and archaeal communities. Taking into account the percentage of shared OTUs (operational taxonomic units) of each domain evaluated, we concluded that the domain Bacteria were more influenced by the deforestation than the Archaea. A total of 22 % of bacterial OTUs and 50 % of the archaeal OTUs were shared between forest and grassland leading us to conclude that the environment evaluated presented a core microbial community that did not suffer modification caused by land use change.

Olive agroforestry shapes rhizosphere microbiome networks associated with annual crops and impacts the biomass production under low-rainfed conditions

“…Shared prokaryotes OTUs (95%) between AF and SC were not affected by the presence of an olive tree or crop species. At least two hypotheses can explain this: (i) the soil rhizosphere is the primary driver of bacterial and archaeal communities, which is supported by previous works reporting that soil type strongly influences bacterial and archaeal communities irrespective of the absence or presence of vegetation (Lupatini et al, 2013;Suleiman et al, 2017) or (ii) there is a well-adapted soil prokaryote community, independent of vegetation cover or soil properties (e.g., high % TOC in AF plots) that can exhibit an outstanding level of similarity despite several modifications in soil properties (Marshall et al, 2011;Wallenius et al, 2011). In contrast, fungal communities consisted of a lower proportion of shared OTUs (an average of 50%) between the two types of agrosystems and a smaller number of specific OTUs per soil crop species among AF samples than SC samples, suggesting the importance and the Network topology plots of the core microbial communities associated with root systems of cereals and legumes crops in an agroforestry system (AF) and full sun cropping (SC) samples.…”

Effect of Clearance on the Soil Fungi Community in Chaco Dry Forest

“…The diversity indices were not in uenced by the different soil management, such as deforestation and agricultural use, but not for the H´ DGGE. Therefore, some species are more sensitive than others and may not be detected in conventional studies, but yes at the metagenomic level as in this work (AhmadSuleiman et al, 2016; González-Chávez et al, 2010). It can be said that complementary studies between traditional and molecular techniques are relevant and useful to known how the ecosystem works of SOC possibly due to the accumulation of plant remains due to zero tillage, this would favour the presence of pathogenic species such as Fusarium spp.…”

No-tillage for flooded rice in Brazilian subtropical paddy fields: history, challenges, advances and perspectives

“…Soil microbial species are also influenced by soil use and management (Suleiman et al, 2017). Recently, advances related to next-generation molecular sequencing technologies enabled the profile identification of microorganism species and genera influenced by the adoption of NT, crop rotation, use of cover crops, and other management practices (Suleiman et al, 2013).…”