1,720,979 research outputs found
Microbial communities in different components of an Alpine grassland ecosystem
Full text linkAim: Biodiversity is a central keyword of the 21st century and is gaining even increasing attention in the light of global change. Whereas traditional concepts of studying microbial diversity consider individual components or taxa in a given habitat (e.g. bulk soil, plants, earthworms), these concepts neglect that complex interactions and co-occurrences of microbial communities may exist between these components. Methods: The prokaryotic and fungal community composition of different sample types (components), including bulk soil, rhizosphere soil of Carex spp. and Festuca spp., members of the micro- (nematodes), meso- (collembolans), and macro- (earthworms, ground and rove beetles) fauna, as well as fecal samples of wild mammals (hare, deer) and domestic livestock (cattle, equids) are investigated by amplicon sequencing along an elevational gradient from 1000 to 2500 m a.s.l. A meta-dataset of soil properties, soil microbial and meteorological data contributes to the interpretation of the community data of the almost 2000 samples within the alpine grassland ecosystem. Results: Soil, rhizosphere and faunal samples each have unique microbial communities, but these microbiota overlap to different degrees, depending on functional traits, trophic relationships and elevation. Our data indicate connections between microbial communities of different ecosystem components and that certain animals can serve as vectors for various microorganisms. Generally, results reveal key drivers for the microbial biodiversity within the different components of alpine grasslands. Conclusions: Our data prove – even across the elevation gradient – connected microbial communities in alpine pastures and allow conclusions about the sensitivity of the complex interactions especially in light of climate chang
Microbial diversity in mountain soils: microbial co-occurrences in animals, rhizosphere and soils in the context of climate change
No full textInteractions of plant growth-promoting microbes with (soil) animals in Alpine pastures
Full text linkThe soils of Alpine pastures provide diverse habitats for animals, plants and microorganisms and are known as hotspots for biodiversity. In particular, soil microbes have a significant role in soil function. The international project MICROVALU is evaluating the microbial diversity in Alpine pastures by analyzing different components of the soil food web including soil, rhizosphere soil, invertebrate fauna and fecal samples of dominant above-ground mammals and tries to provide a more complete understanding of the relationship between soil organisms and their effect on soil processes. The association of plants with plant growth-promoting microbes (PGPM) is substantial for plants to cope environmental stress, e.g. caused by climate change, and is essential for fruitful and sustainable agriculture in Alpine regions. Therefore, in addition to assessing overall microbial diversity patterns, we are focusing on possible driving factors for the abundance and composition of PGPM that live in close association with the roots of plants. These organisms provide the plant with beneficial services ranging from nitrogen fixation and phosphate solubilization, to phytopathogen suppression via antibiotic production, resulting in better plant growth, faster germination, enhanced root growth, and higher resistance against abiotic and biotic stress. Since the impact of factors like elevation, temperature, drought and interactions and/or transmissions via the soil fauna on PGPM is limited, this particular study is also ground-breaking. For this study, samples from bulk soil, rhizosphere soil of two common plant genera in Alpine pastures (Carex spp. and Festuca spp.), belowground fauna (micro-, meso- and macrofauna) and fecal pellets of above ground fauna (wild animals and domestic livestock), were collected along an elevational gradient of an inner-Alpine valley from below to above the treeline (1000-2500 m a.s.l.). Microbial abundance, community composition, and diversity were determined in all sample types, and special focus is now being paid on the abundance and diversity of PGPM. Our results will identify the associations of PGPM in the rhizosphere and the associations and possible transmission of PGPM between soil and soil animals in Alpine pastures under changing environmental conditions
Changes in ground-dwelling carabid communities and their interactions with the microbiota of selected soil compartments along an Alpine elevational gradient
No full textGlobal warming is affecting Alpine habitats through an increase in temperature above the global average. Such rapid environmental change may affect biotic interactions and thus ecosystem stability and functionality; however, these pro- cesses in mountain soils are not well understood. We used an elevation gradient ranging from 1000 to 2500 m a.s.l. as a proxy for climate change to investigate the diversity of ground-dwelling car- abid beetle species and selected body traits. We also analysed the microbiota of the beetles and other soil-associated compartments to under- stand the complex interactions and co-occur- rences of microbial communities in alpine soils. On 12 grazed pastures (3 replicate sites every 500 m of altitude), we set up pitfall traps for an entire growing season and emptied them every two weeks. Nearly 6000 individuals were captured and morphologically identified to spe- cies, with body length, wing development and sex recorded. In addition, 182 carabid beetles were collected by hand, and used for microbial community analysis by next-generation sequenc- ing. For comparison, microbiota analyses were also performed on soil, rhizosphere, nematode, collembola, earthworm and vertebrate faecal samples. Community composition and diversity of carabids changed significantly with elevation, but not in a linear pattern. Especially the prokaryotic commu- nities in carabid beetles showed trophic related patterns. Compared to the other soil-associated compartments, bacterial and fungal alpha and beta diversity in carabids was very low and few taxa were shared. Our data confirm ecological patterns along elevation and provide a first insight into the complex interactions between soil, faunal and microbial players
Changes in carabid species distribution, body traits and associated microbiota along an elevational gradient
No full textGlobal warming is affecting alpine habitats through a temperature increase above the global average. Such rapid environmental change can affect biotic interactions, impacting ecosystem stability and functionality; however, these processes in mountain regions are not well understood. We used an elevation gradient ranging from 1,000 to 2,500 m a.s.l. as a proxy for climate change to examine the diversity of carabid beetle species, body traits and their individual microbiota. On 12 grazed pasture sites (3 replicate sites every 500 m of altitude), we installed and checked pitfall traps for 24 hours every two weeks throughout the growing season. Almost 6,000 individuals were morphologically identified to species, and body length, wing development, sex and trophic status were noted. Additionally, 182 carabid beetles were captured by hand, and used for microbial community analysis. Community composition, diversity, and the ratio between winged and wingless species of carabid beetles changed significantly, but non-linearly with elevation. Carabids established individual-specific but still elevation-dependent patterns in prokaryotic and fungal communities. Prokaryotic communities were similar below 2,000 m but changed at higher elevations and fungal diversity was highest at 2,000 m. Such data will help us understand how global warming is affecting biotic interactions in soil
The role of microbiodiversity in conservation: insights from ecosystem metataxonomics
Full text linkAs microbial communities hosted in various body niches (microbiota) are of recognized importance to individual health, the maintenance of such microbiodiversity in natural ecosystems could impact the conservation status of animal species. Metataxonomy using amplicon sequencing has become the standard for characterizing the diversity and composition of microbial communities associated with multicellular organisms and their environment, and numerous studies have now shown that human- and climate-mediated behavioural and dietary changes in wild animal populations are associated with changes in microbiota richness and composition. However, identifying the interactions between the microbiotas within the same ecosystem (i.e. those of water, soil, plants and animals) is essential for fully understanding the role of microorganisms in evolutionary and ecological processes. Comparative studies across such diverse biological samples are rare, due to potential biases during sample processing. Here we discuss the technical adjustments that can be applied to support direct comparisons of microbiota composition, using a terrestrial alpine ecosystem as a case study. We also show how microbial communities from 900 samples (1900 libraries) of wild vertebrates and invertebrates vary with those of domestic breeds and environmental microbiotas (soil and rhizosphere) across an altitudinal gradient, with implications for microdiversity conservation in light of climate and land use change
Changes in carabid species distribution, body traits and associated microbiota along an elevational gradient
Full text linkAim: Climate warming is affecting Alpine habitats through an above-global average increase in temperature. Such rapid environmental change can affect biotic interactions, impacting ecosystem stability and functionality; however, these processes in mountain regions are not well understood. We used an elevation gradient ranging from 1000 to 2500 m a.s.l. as a proxy for climate change to examine the diversity of carabid beetle species, body traits and microbiota. Methods: On 12 grazed pasture sites (3 replicate sites every 500 m of altitude), we installed and checked pitfall traps for 24 hours every two weeks throughout the growing season. Almost 6000 individuals were morphologically identified to species, and body length, wing development and sex were noted. In June 2020, 182 carabid beetles were captured by hand, and used for microbial community analysis. Results: Community composition, diversity, and the ratio between winged and wingless species of carabid beetles changed significantly with elevation, but not in a linear pattern (ie. highest species biodiversity at 1000 m; lowest diversity and largest body size at 2000 m). Carabids established individual-specific but still elevation-dependent patterns in prokaryotic and fungal communities. Prokaryotic communities were similar below 2000 m but changed at higher elevations and fungal diversity was highest at 2000 m. Conclusions: We discuss how changes in species assemblages and body traits may alter the functional role of carabid beetles in mountain ecosystems, and how alterations in their microbiota might impact their ability to adapt to rapid environmental perturbation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Interactions among soil organisms of the Alpine pasture ecosystem
Full text linkAn intact soil ecosystem is the basis for sustainable agriculture and hence human wellbeing. Soil microorganisms, plants and animals play many different roles in soil ecosystems, yet live in direct contact with one another. In fact, the composition of these communities impacts soil fertility and structure, important to nutrient cycling and plant health. In addition to soil microorganisms, all plant and animal species living in the soil host their own microbial communities; however, if and how these microbial communities interact with each other is almost completely unexplored. Ongoing climate change scenarios have recently increased the awareness of the importance of soil biodiversity and expected changes in response to altered environmental conditions, and Alpine soils are predicted to undergo even more drastic changes in the near future. So far, no study has investigated the combined impacts of biotic interactions and abiotic/climatic factors on the biodiversity of soil organisms in vulnerable Alpine soils. The EUREGIO project MICROVALU is evaluating the prokaryotic and fungal diversity of the main inhabitants of Alpine pasture ecosystems to provide a more complete understanding of the relationships between soil organisms and their effect on soil processes. For this study, samples of bulk soil, rhizosphere soil of two plant genera (Carex spp. and Festuca spp.), microfauna (nematodes), mesofauna (collembolans) and macrofauna (earthworms and beetles), as well as fecal pellets of above ground fauna (wild mammals and domestic livestock) were collected along an elevational gradient of an inner-Alpine valley (1000 - 2500 m a.s.l.). Microbial community composition of all samples was determined using our laboratory protocols optimized here for the first time to permit the comparison of microbiota from diverse matrices. Our results indicate that each sample type harbors a unique core microbiota, overlapping to a different extent with other members of the ecosystem. Combining microbial community data with abiotic soil properties and climatic factors along an elevational gradient gives new insights into the microbial co-occurrences of soil members among changing environmental and climatic condition
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