Download or read book Effects of Experimental Warming and Clipping on Metabolic Change of Microbial Community in a US Great Plains Tallgrass Prairie written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: While more and more studies are being conducted on the effects of global warming, little is known regarding the response of metabolic change of whole soil microbial communities to this phenomenon. In this study, functional gene changes at the mRNA level were analyzed by our new developed GeoChip 3.0. Soil samples were taken from a long-term climate warming experiment site, which has been conducted for ~;;8 years at the Kessler Farm Field Laboratory, a 137.6-ha farm located in the Central Redbed Plains, in McClain County, Oklahoma. The experiment uses a paired factorial design with warming as the primary factor nested with clipping as a secondary factor. An infrared heater was used to simulate global warming, and clipping was used to mimic mowing hay. Twelve 2m x 2m plots were divided into six pairs of warmed and control plots. The heater generates a constant output of ~;;100 Watts m-2 to approximately 2 oC increase in soil temperature above the ambient plots, which is at the low range of the projected climate warming by IPCC. Soil whole microbial communities? mRNA was extracted, amplified, labeled and hybridized with our GeoChip 3.0, a functional gene array covering genes involved in N, C, P, and S cycling, metal resistance and contaminant degradation, to examine expressed genes. The results showed that a greater number and higher diversity of genes were expressed under warmed plots compared to control. Detrended correspondence analysis (DCA) of all detected genes showed that the soil microbial communities were clearly altered by warming, with or without clipping. The dissimilarity of the communities based on functional genes was tested and results showed that warming and control communities were significantly different (P

Download or read book Ecosystem Consequences of Soil Warming written by Jacqueline E. Mohan and published by Academic Press. This book was released on 2019-04-12 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecosystem Consequences of Soil Warming: Microbes, Vegetation, Fauna and Soil Biogeochemistry focuses on biotic and biogeochemical responses to warmer soils including plant and microbial evolution. It covers various field settings, such as arctic tundra; alpine meadows; temperate, tropical and subalpine forests; drylands; and grassland ecosystems. Information integrates multiple natural science disciplines, providing a holistic, integrative approach that will help readers understand and forecast future planetwide responses to soil warming. Students and educators will find this book informative for understanding biotic and biogeochemical responses to changing climatic conditions. Scientists from a wide range of disciplines, including soil scientists, ecologists, geneticists, as well as molecular, evolutionary and conservation biologists, will find this book a valuable resource in understanding and planning for warmer climate conditions. - Emphasizes biological components of soils, plants and microbes that provide linkages to physics and chemistry - Brings together chapters written by global scientific experts with interests in communication and education - Includes coverage of polar, alpine, tropical, temperate and dryland ecosystems

Download or read book Microbial Responses to Environmental Changes written by Jürg B. Logue and published by Frontiers Media SA. This book was released on 2016-01-20 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in next generation sequencing technologies, omics, and bioinformatics are revealing a tremendous and unsuspected diversity of microbes, both at a compositional and functional level. Moreover, the expansion of ecological concepts into microbial ecology has greatly advanced our comprehension of the role microbes play in the functioning of ecosystems across a wide range of biomes. Super-imposed on this new information about microbes, their functions and how they are organized, environmental gradients are changing rapidly, largely driven by direct and indirect human activities. In the context of global change, understanding the mechanisms that shape microbial communities is pivotal to predict microbial responses to novel selective forces and their implications at the local as well as global scale. One of the main features of microbial communities is their ability to react to changes in the environment. Thus, many studies have reported changes in the performance and composition of communities along environmental gradients. However, the mechanisms underlying these responses remain unclear. It is assumed that the response of microbes to changes in the environment is mediated by a complex combination of shifts in the physiological properties, single-cell activities, or composition of communities: it may occur by means of physiological adjustments of the taxa present in a community or selecting towards more tolerant/better adapted phylotypes. Knowing whether certain factors trigger one, many, or all mechanisms would greatly increase confidence in predictions of future microbial composition and processes. This Research Topic brings together studies that applied the latest molecular techniques for studying microbial composition and functioning and integrated ecological, biogeochemical and/or modeling approaches to provide a comprehensive and mechanistic perspective of the responses of micro-organisms to environmental changes. This Research Topic presents new findings on environmental parameters influencing microbial communities, the type and magnitude of response and differences in the response among microbial groups, and which collectively deepen our current understanding and knowledge of the underlying mechanisms of microbial structural and functional responses to environmental changes and gradients in both aquatic and terrestrial ecosystems. The body of work has, furthermore, identified many challenges and questions that yet remain to be addressed and new perspectives to follow up on.

Download or read book Responses to Long term Fertilization and Burning written by Michael A. Carson and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic activities impact ecosystems in numerous direct and indirect ways, affecting the cycling of carbon (C) and nitrogen (N) on local, regional and global scales. North America tallgrass prairie is an ecosystem profoundly altered by anthropogenic activities, with most native prairie converted to alternate land uses or heavily impacted by other environmental changes. While aboveground responses to anthropogenic drivers have received much attention, the responses of belowground biota, ecological processes, and nutrient allocation to land management and environmental change are poorly documented, especially over long timeframes. This research builds upon a long-term experiment (the Belowground Plot Experiment) initiated in 1986 at Konza Prairie Biological Station (Manhattan, KS). I utilized a subset of treatments to address the effects of annual burning vs. fire suppression and/or chronic N additions on soil C and N dynamics and microbial communities in tallgrass prairie. I measured a suite of soil variables related to C and N cycling during the 2012 growing season, including total soil C and N, microbial biomass C and N, in situ net N mineralization, potential N mineralization, in situ CO2 efflux, and potentially mineralizable soil C.I also assessed changes in microbial community composition using microbial phospholipid fatty acids (PLFA) profiles. Annual burning significantly (p[less then or equal to]0.05) increased the soil C:N ratio and in situ CO2 efflux, while decreasing potential ammonification and nitrification rates. Annual burning also increased total PLFA mass and relative abundance of fungi. Chronic N addition (100 kg N ha−1 year−1) significantly reduced the soil C:N ratio, while increasing total soil N and potential nitrification and ammonification rates. Chronic N addition reduced potential C mineralization, microbial biomass C and N, and altered microbial community composition by increasing abundance of bacterial PLFAs and reducing fungal PLFAs. Sampling date also significantly affected many variables. These results indicate that different fire regimes and chronic N enrichment over decades affects soil C and N pools and transformations, as well as microbial biomass and composition. In total, this study highlights the importance of long-term ecological research and identifies likely changes in tallgrass prairie nutrient dynamics and soil microbial communities under increased N and frequent burning.

Download or read book Climate Legacies and Restoration History as Drivers of Tallgrass Prairie Carbon and Nitrogen Cycling written by Caitlin M. Broderick and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change is expected to alter precipitation amounts and distributions, resulting in longer, more frequent periods of wet and dry conditions in the North American Central Plains. Grasslands in this region are often limited by water availability, so novel rainfall patterns will likely affect ecosystem functioning. The rates of two key carbon (C) fluxes, aboveground net primary productivity (ANPP) and soil respiration, are tightly linked to water availability in these grasslands. Moreover, the cycling of nitrogen (N), a co-limiting nutrient, is tied to soil moisture through microbially-mediated processes such as N mineralization, microbial immobilization, and nitrification. Decomposition unites these two cycles-controlling the rate of C sequestration and N release-and can be slowed by both droughted and saturated soils. There is a growing understanding that sufficiently long and/or intense precipitation anomalies (e.g., extended wet or dry periods) can affect ecosystem processes even after the climate event ceases, resulting in climate "legacy effects". Tallgrass prairies, at the eastern and wetter end of the Central Plains grasslands, are both sensitive and highly resilient to short-term climate variability but the extent to which this climate sensitivity and resilience is shaped by previous climate history is largely unknown. If altered climate patterns cause changes in key ecosystem properties such as plant communities, microbial community functioning, or soil attributes, these climate changes may exert legacies on rates of prairie C and N cycling. Finally, while the relationship between climate and intact grassland ecosystem functioning has been relatively well-studied, less than five percent of North American tallgrass prairie remains intact. As a result, the persistence of tallgrass prairies and their associated ecosystem services relies heavily on the successful restoration of functioning prairies; yet future restorations will likely occur under a more hostile climate. It is therefore important to assess how climate sensitivity and resilience develops as restored prairies mature. In this dissertation, I assessed how past and current climate conditions interact to affect C fluxes, N transformations, and decomposition rates in native tallgrass prairie. I used a long-term experiment at Konza Prairie, KS, in which rainfall was supplemented by irrigation water to release tallgrass prairies from water stress for ~25 years. In 2017, I switched the irrigation and ambient treatments in a subset of plots and added new drought treatments across both historic treatments, allowing me to assess (i) how short- and long-term climate patterns differ in their effects on prairie ecosystems, (ii) whether previous climate patterns continue to shape current prairie functioning via climate legacies, and (iii) whether previous climate altered the sensitivity of prairie C and N cycling to drought conditions. In a separate project, I imposed an experimental drought across restored prairies ranging from 4 to 22 years old and measured how the sensitivity of prairie structure and function to water stress varied with restoration age. I found that a historically wetter climate increased ANPP and soil respiration on a magnitude comparable to current wet conditions, and that a history of irrigation conferred greater drought resistance to key ecosystem processes lasting up to three years. A history of irrigation also increased net N mineralization rates and nitrification rates, and microbial C/N ratios and extracellular enzyme investment suggested reduced N limitation of belowground N cycling. This legacy of increased N supply with a history of irrigation may support the higher-than-expected rates of C fluxes after ceasing irrigation. In contrast, root decomposition rates were slowest with long-term irrigation, suggesting that the increased rates of C and N mineralization may be more due to legacy effects on SOM processing than litter decay. Notably, legacy effects across response variables were most often found in lowland prairie, suggesting that topoedaphic factors are important for determining the strength of biogeochemical climate legacies. Finally, I found that restored prairie plant communities, ANPP, soil respiration, and labile N pools were surprisingly resistant to drought across all restoration ages, offering hope that restoration efforts may not be significantly hindered by future climate variability.

Download or read book Carbon and Nitrogen Dynamics and Microbial Community Structure of a Tall Grass Prairie Soil Subjected to Simulated Global Warming and Clipping written by Asfaw Belay Tedla and published by . This book was released on 2004 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regional climate and Local microbial Controls on Ecosystem Processes During Grassland Restoration written by Meredith Lynne Mendola and published by . This book was released on 2013 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Root productivity likely has consequences for the composition, activity, and recovery of soil microbial populations and the belowground processes mediated by these organisms. In tallgrass prairie, ecotypic variation potentially exists in response to a strong precipitation gradient across the Great Plains. Thus, ecotypic variation within a species may differentially affect belowground net primary productivity (BNPP), the associated soil microbial community, and may scale up to affect ecosystem processes. The goals of this study were to elucidate: (1) whether ecotype, environment, or an ecotype by environment interaction regulate BNPP of a dominant species ( Andropogon gerardii ) collected from and reciprocally planted in common gardens across a precipitation gradient, and (2) whether variation in BNPP scales to affect microbial biomass and ecosystem processes. I quantified root biomass, BNPP (using root ingrowth bags), soil microbial biomass, and nutrient mineralization rates in root-ingrowth cores below six population sources of A. gerardii (2 Illinois, 2 eastern Kansas, and 2 central Kansas) established in southern Illinois, eastern Kansas, and central Kansas. An ecotype effect was found on above and belowground net primary productivity, but these findings did not translate to soil response variables. Microbial populations themselves may affect the productivity and composition of prairie species. In a second study, soil ecological knowledge (SEK) was tested by applying a native prairie soil slurry amendment to restoration plots to determine efficacy of this method as a restoration practice. The goals of this two year study were to elucidate: (1) whether a slurry amendment of prairie soil would increase above and belowground productivity and belowground ecosystem processes in a prairie restoration, and (2) to evaluate whether differences in plant diversity will scale to affect belowground productivity and ecosystem processes. I quantified aboveground net primary productivity (ANPP) and species composition, as well as root biomass, belowground net primary productivity (BNPP), soil microbial biomass, and nutrient mineralization rates in root-ingrowth cores installed in treated and control plots. A treatment effect was noted on root biomass and total PLFA biomass; however, there was no treatment effect on cover, ANPP, or soil microbial processes. Though the soil microbial community did represent native prairie soil, there was poor establishment of prairie plant species. These factors may be due to the limited time available for data collection and the lack of precipitation in the second growing season. Longer studies may be necessary to fully examine the effects of soil slurry amendments as restoration tools.

Download or read book Changes in Soil Microbial Communities After Long term Warming Exposure written by William G. Rodríguez-Reillo and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial metabolism is a key controller of ecosystem processes (e.g., carbon cycling). However, we are only starting to identify the molecular mechanisms and feedback in response to long-term warming. My dissertation integrates multi-omics techniques to capture changes in soil microbial communities after long-term warming exposure. The research projects leverage three warming sites (i.e., SWaN, Barre Woods, and Prospect Hill) located in Western Massachusetts at Harvard Forest. These sites provided a unique experimental setup to better understand microbes in response to long-term temperature change. For the three research projects, we delved into the (i) microbial biodiversity across all three warming sites, (ii) integration of soil carbon chemistry and metatranscriptomics at the Barre Woods site, (iii) and a time series of soil metatranscriptomes at the Prospect Hill site. Overall, these studies revealed a broader scope of changes occurring with long-term warming than anticipated. The warming treatment induced shifts in fungi groups and recalcitrant carbon decomposer bacteria. Changes in microbial functions involved metabolic pathways associated to biogeochemical and cellular stability as result of nutrient limitation. Further, our results provided new insights in microbial response to chronic temperature stress, suggested an ongoing change in community structure and function, and linked soil carbon decrease to cellular processes using high throughput molecular techniques. This information will help to better understand interactions between microbial communities and the Earth's climate.

Download or read book Stronger Warming Effects on Microbial Abundances in Colder Regions written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil microbes play critical roles in regulating terrestrial carbon (C) cycle and its feedback to climate change. However, it is still unclear how the soil microbial community and abundance respond to future climate change scenarios. In this meta-analysis, we synthesized the responses of microbial community and abundance to experimental warming from 64 published field studies. Our results showed that warming significantly increased soil microbial abundance by 7.6% on average. When grouped by vegetation or soil types, tundras and histosols had the strongest microbial responses to warming with increased microbial, fungal, and bacterial abundances by 15.0%, 9.5% and 37.0% in tundra, and 16.5%, 13.2% and 13.3% in histosols, respectively. We found significant negative relationships of the response ratios of microbial, fungal and bacterial abundances with the mean annual temperature, indicating that warming had stronger effects in colder than warmer regions. Moreover, the response ratios of microbial abundance to warming were positively correlated with those of soil respiration. Our results therefore indicate that the large quantities of C stored in colder regions are likely to be more vulnerable to climate warming than the soil C stored in other warmer regions.

Download or read book Effects of Traditional and Microbially focused Restoration Techniques on Soil Communities in Tallgrass Prairies written by Zachary J. Whitacre and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tallgrass prairies have virtually disappeared in many parts of their former range due to the conversion of this ecosystem to farmland. In more recent years there have been efforts to restore these prairies on reclaimed agricultural land. However, these restored prairies do not resemble their remnant counterparts in many ways, such as in soil microbial community composition and metrics related to carbon storage. In Chapter 1, I show that bacterial communities in a restored prairie and an adjacent remnant prairie in southwest Michigan differ in their immediate and longer-term responses to prescribed fire, a commonly used prairie restoration and maintenance technique. Overall, results show that bacterial communities in the remnant prairie were more resilient to the prescribed fire event than the bacterial communities in the restored prairie. In Chapter 2, I explore the effects of carbon addition in the form of pure cellulose and plant biomass as well as the effects of plants and soil type on soil microbial communities and metrics related to carbon storage and in two new prairie restorations, one in southwest Michigan and one in eastern Minnesota. We found that through biomass addition there were increases in metrics related to carbon storage in both prairies when plants were present. Conversely, the response of the soil microbial communities differed in these two restorations in response to carbon addition and the presence of plants suggesting that differences in soil type can set restorations of different trajectories.

Download or read book Responses of a Tallgrass Prairie to Experimental Warming written by Shiqiang Wan and published by . This book was released on 2002 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plant and Insect Responses to Experimental Warming in a Temperate Grassland written by Troy Shaun Dunn and published by . This book was released on 2017 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: Community structure is being altered by direct and indirect effects of climate change. Increasing temperatures can threaten community structure resulting in the disruption of interactions within those communities most sensitive to changes in climate. Among those communities at risk for change is the North American grassland habitat and its resident insect community. Climate change can potentially affect primary production and the abundance and diversity of both plants and animals in different ecosystems. Here we have used open-top chambers to study the impact warming temperatures have on the resident plant and insect community on grassland habitat in order to better understand how grassland areas are affected and may change as a result of global warming, and how climate change will impact the community and ecosystem as a whole. Results show that passively warmed open-top chambers have a measureable increase of 1-4°C in ambient temperature above that of the controls. Results also show no significant treatment effects of temperature on primary production, except for litter, and no significant effect on the abundances of the resident insect community as a whole. Interestingly, results do reveal significant effects of treatment on insect taxonomic orders and families as well as significant effects on the trophic levels within the grassland habitat confirming that insects are responding in different ways to artificial warming, which can ultimately alter trophic dynamics directly and indirectly.

Download or read book Effects of Warming and Clipping on Carbon and Nitrogen Content and Their Isotope Ratios in Soil Organic Matter Aggregates in a Tall Grass Prairie Ecosystem written by Afzal Azizullah Subedar and published by . This book was released on 2005 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Long term Effects of Climate Change on Grassland Soil Systems written by Steven Charles Jr Rostkowski and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change predictions for the Great Plains region of North America include increased temperatures, changes to annual precipitation, and reduced growing season precipitation, which will likely alter grassland soil systems. To date, few studies have examined belowground community responses to predicted climate change scenarios, with fewer assessing long-term changes. My research focused on the impacts of long-term changes in precipitation and associated soil water content on belowground grassland systems (belowground plant biomass, soil carbon (C) and nitrogen (N) pools, microbial biomass C and N, and invertebrate communities) using recently collected samples from a long-term (16-yr) reciprocal core transplant between Konza Prairie Biological Station (MAP = 850 mm) and Kansas State Agricultural Research Center at Hays (MAP = 580 mm), with the Hays site having a long-term average annual precipitation amount that is ~30% less than the Konza site. Results from the experiment indicate that either increases or decreases in annual precipitation can have profound effects on belowground grassland systems. Belowground plant biomass, microbial biomass, and potential C mineralization rates were greater at the wetter Konza site regardless of soil origin. Total C stored in soils incubated at Konza was significantly greater as well, likely due to greater root inputs. The effects of precipitation were most apparent in the surface soil layers (0-20 cm), while soil origin impacted soil properties to a greater extent with increasing depth. This contrasted with results for the soil mesofauna, where total microarthropods responded negatively and nematodes responded positively to increased annual precipitation. Results of this study indicate important changes in soil C and N pools, belowground plant biomass, and soil mesofauna within grassland systems subject to changing precipitation regimes, and suggest more mesic prairie systems are more sensitive to changes in soil water availability than those in more arid grassland systems.

Download or read book The Effects of Warming and Land use on Species Composition in the Tallgrass Prairie written by Sarah E. Bowdish and published by . This book was released on 2002 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Great Plains Regional Technical Input Report written by Jean Steiner and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prepared for the 2013 National Climate Assessment and a landmark study in terms of its breadth and depth of coverage, Great Plains Regional Technical Input Report is the result of a collaboration among numerous local, state, federal, and nongovernmental agencies to develop a comprehensive, state of the art look at the effects of climate change on the eight states that encompass the Great Plains region. The Great Plains States are already experiencing the impacts of a changing climate, and will likely continue to experience warming temperatures, more extreme precipitation events, reduced snow and ice cover and rising relative sea levels. The book presents a review of the historic, current, and the projected future climate of the region; describes interactions with important sectors of the Northeast and examines cross-sectoral issues, namely climate change mitigation, adaptation, and education and outreach. Rich in science and case studies, it examines the latest climate change impacts, scenarios, vulnerabilities, and adaptive capacity and offers decision makers and stakeholders a substantial basis from which to make informed choices that will affect the well-being of the region's inhabitants in the decades to come.

Download or read book Adaptation of Soil Fungi to Warming and Consequences for Decomposition and the Carbon Cycle written by Adriana L. Romero-Olivares and published by . This book was released on 2017 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studying soil carbon (C) losses and carbon dioxide (CO 2) feedbacks to the atmosphere under global climate change allows us to quantify and understand how our ecosystems are responding to warming. To accurately project the fate of the terrestrial C, we need to incorporate processes that are pivotal in shaping microbial communities that are responsible of processing the C in the soil. One of these processes is the evolutionary adaptation to warming which has been difficult to study because it may only be noticeable on the long term. The goal of my dissertation was to examine soil microbes, their response and adaptation to warming, and consequences to the C cycle. In Chapter 1, I synthesized data from 25 field warming experiments to assess the effect of microbial responses---relevant to the C cycle---to warming over time. I found that the effect of soil respiration decreases as warming progresses and explored the potential microbial-related causes of this decrease. In my second chapter, I experimentally adapted the model fungus Neurospora discreta to warming and analyzed physiological traits important for the C cycle before and after adaptation. I discovered that when N. discreta adapts to warming it allocates more resources to increase its fitness by producing more spores at the expense of biomass. I found that adaptation to warming is accompanied by increases in CO2 respiration potentially due to higher production of energetically expensive spores. In this chapter, I discussed the potential consequences for the terrestrial C if the soil microbial community adapts in a similar manner as N. discreta . Finally, in my third chapter, I quantified decomposition of specific C fractions in litter in a long-term field warming experiment. I found that the proportional losses of recalcitrant vs non-recalcitrant C was higher in warmed plots compared to control plots. Similarly, the ratio of microbial extracellular enzyme activities responsible for breaking down recalcitrant C was higher under warming compared to enzymes that break down non-recalcitrant C. Collectively, in my dissertation research I integrated the process of evolutionary adaptation of microbes to warming, thus providing an overview of the potential long-term effects of warming to decomposition and the C cycle.