Download or read book Environmental Heterogeneity Effects on Diversity and Nitrous Oxide Emissions from Soil in Restored Prairie written by Drew A. Scott and published by . This book was released on 2019 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecological theory predicts that high environmental heterogeneity causes high biodiversity. Theory further predicts that more biodiversity results in greater ecosystem functioning. These theoretical predictions were evaluated in three studies using grassland restorations from agriculture. The 'environmental heterogeneity hypothesis' has been proposed as a mechanism that enables species coexistence through resource partitioning. In accordance with this hypothesis, plant diversity is predicted to increase with variability in resources, but there has been weak support for this hypothesis from experimental studies. The objective of this research was to characterize how resource availability and heterogeneity (coefficient of variation) change as plant communities develop using a chronosequence of restored prairies. More specifically, we quantified means and coefficients of variation in soil nitrate and light availability (proportion of photosynthetically active radiation [PAR] reaching soil surface) in prairies established on former agricultural lands for different times (ages) and their relationship to plant diversity and community structure using a geostatistically informed design. Nitrate availability decreased exponentially with restoration age, but there was no directional change in nitrate heterogeneity across the chronosequence. Light availability also decreased exponentially across the chronosequence, but PAR heterogeneity increased with restoration age. Heterogeneity in resources did not affect plant community structure, but heterogeneity in nitrate and light were positively related to plant Shannon's Diversity (H). The heterogeneity effects on H were less when considering nitrate and PAR availability. Similarly, richness responded positively to heterogeneity in nitrate and PAR, but only nitrate heterogeneity effects were weakened by resource availability. No significant heterogeneity effects were found for Pielou's evenness, suggesting diversity responses to heterogeneity were mostly driven by changes in richness. Overall, these results suggest that environmental heterogeneity corresponds with plant diversity as predicted by the 'environmental heterogeneity hypothesis', but high resource availability can weaken this relationship. Plant species identity, soil depth, soil nutrient availability, and their interactions have the potential to structure soil microbial communities. If distinct communities were present within combinations of different combinations of levels of these ecosystem properties, this would indicate heterogeneity promotes soil microbial diversity. I used a 20 year restored prairie with soil depth (shallow and deep) and nutrient manipulation (reduced N availability, ambient N availability, and elevated N availability) and used three plant treatments (Andropogon gerardii, Salvia azurea, and bare soil) to evaluate the relative effects of these treatments and their interactions on the soil microbial community as measured by phospholipid fatty acid (PLFA) profiles. Permutational multivariate analysis of variance of PLFA biomass was conducted as was mixed model analysis of Shannon diversity index (H), richness (S), and Pielou's evenness (J). Treatments had no effect on microbial community structure. The main effect of plant species treatment influenced PLFA H. This was due to differences between bare soil and the two rhizosphere soils, where rhizosphere soils had greater proportional arbuscular mycorrhizal fungi and Gram-negative bacteria. This indicates that increasing plant cover promotes microbial diversity. While we did not detect distinct microbial communities in treatment combinations, molecular methods may be more sensitive and indicate if environmental heterogeneity is likely to promote soil microbial diversity. Plant diversity has been shown to increase several ecosystem functions including primary productivity, nutrient retention, and carbon sequestration. We tested if plant diversity could mitigate nitrous oxide emissions. We used an initial survey to determine study design from quadrat and semivariogram analyses and to determine cutoffs for high- and low-plant diversity. We sampled high- and low-diversity plant communities from five 10 to 12 y restorations co-located at Nachusa grasslands (Franklin Grove, IL, USA). We demonstrated that the diversity treatments were associated with high- and low-levels of species richness, species evenness, and functional group richness. We found the nitrous oxide emissions from high-diversity plant communities were approximately half the emissions from low-diversity plant communities. Differences in emissions did not coincide with differences in water availability, nitrogen availability, carbon availability, or microbial activity. Soils exhibited more N2O emission hotspots from denitrification in the low plant diversity treatment. This suggests that plant diversity is affecting the physiology or the community structure of soil denitrifiers. This work indicates that nitrous oxide emissions can be managed by creating high-diversity plant communities.

Download or read book Soil Emission of Nitrous Oxide and its Mitigation written by David Ussiri and published by Springer. This book was released on 2012-11-12 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrous oxide gas is a long-lived relatively active greenhouse gas (GHG) with an atmospheric lifetime of approximately 120 years, and heat trapping effects about 310 times more powerful than carbon dioxide per molecule basis. It contributes about 6% of observed global warming. Nitrous oxide is not only a potent GHG, but it also plays a significant role in the depletion of stratospheric ozone. This book describes the anthropogenic sources of N2O with major emphasis on agricultural activities. It summarizes an overview of global cycling of N and the role of nitrous oxide on global warming and ozone depletion, and then focus on major source, soil borne nitrous oxide emissions. The spatial-temporal variation of soil nitrous oxide fluxes and underlying biogeochemical processes are described, as well as approaches to quantify fluxes of N2O from soils. Mitigation strategies to reduce the emissions, especially from agricultural soils, and fertilizer nitrogen sources are described in detail in the latter part of the book.

Download or read book Nitrous Oxide Emissions in a Landscape Transitioning to the Energy Crops Miscanthus and Switchgrass written by Debasish Saha and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrous oxide (N2O) emissions from soils are an important component of the greenhouse gas (GHG) balance of agricultural systems. These emissions are particularly relevant when considering the transition of land under the Conservation Reserve Program (CRP) grassland to energy crop, like switchgrass and Miscanthus. The N2O fluxes are in general spatially and temporally variable, which makes field monitoring of this flux challenging. Using the infrequent chamber-based method requires knowledge of spatial and temporal inequality of N2O flux distribution. This dissertation focuses on estimating N2O flux from energy crops aforementioned in a landscape typical of Ridge and Valley region with soil and hydrologic heterogeneity.In chapter 2, I used simulation models and statistical methods to assess the uncertainties of cumulative N2O flux estimates obtained by different temporal sampling frequencies. As a corollary of this work, a robust rule-based sampling framework was designed that provides better estimates of this flux with a lower number of sampling events than the typical fixed-interval sampling methods. The daily soil N2O flux was simulated for Ames, IA; College Station, TX; Fort Collins, CO, and Pullman, WA. A regular sampling of 4- and 8-day interval is required at College Station and Ames, respectively, to yield ±20% accuracy in the flux estimate, while a 12-day interval renders the same accuracy at Fort Collins and Pullman. The uncertainty of the annual N2O flux estimation increased with increasing interval in the fixed interval method, higher in sites with greater flux variability. The rule-based method provided the same accuracy as that of fixed interval with 60% reduction in sampling numbers. The efficiency is higher in sites with greater flux variability.In chapter 3, I examined the effect of land conversion from CRP to energy crops on N2O emissions and how biogeochemical and hydrological factors control the spatial and temporal inequality of N2O flux distribution. The experiment was located in typical Ridge and Valley landscape near the town of Leck Kill, PA. Soil N2O flux, soil mineral nitrogen availability, and profile soil moisture were monitored in shoulder, backslope, and footslope positions under each plot during the growing season of 2013, the second year after land transition. The cumulative N2O flux was significantly (P = 0.009) influenced by vegetation-by-landscape position interaction. Landscape position, nitrate nitrogen, and subsoil soil aeration ([theta]A) were the most important variables to influence soil N2O emissions. The regression tree identified highest N2O emissions occur when [theta]A at 20-40 cm depth is 0.03 m3 m-3, and when there is nitrate in the soil layer. The footslope positions under energy crops were the hot spots of N2O emissions due to prolonged soil saturation and mineral nitrogen availability. The peak emission was triggered by a 100-mm rain event in early June, and contributed 26% of the cumulative flux. Nitrogen fertilization in switchgrass and chisel plowing during Miscanthus establishment caused 48 and 78% higher cumulative flux than the CRP, respectively. The results suggest that land transition only caused significant increase in N2O emissions from the footslope, while the major part of the watershed is at lesser risk of large emissions.The knowledge of hot spots and hot moments of N2O emissions in the landscape is important for its accurate spatial and temporal monitoring, quantification of the emissions, and to minimize the adverse environmental effects of landscape management. A novel application of the concept of inequality (Lorenz curve and Gini coefficients, G) was used to quantify the heterogeneous distribution of N2O in space and time. The G was better correlated (R2 = 0.71, P 0.001, n = 16) with daily N2O emissions than the coefficient of variation and skewness. The hot moment by 100 mm rain event caused highly heterogeneous distribution (G = 0.70) of N2O fluxes in the landscape; however, had little influence on inequality of soil CO2 (G = 0.39) flux distribution among the vegetation types and landscape positions. Overall inequality of N2O flux distribution followed the trend: footslope (G = 0.75) backslope (G = 0.67) shoulder (G = 0.43). Event-based evolution of N2O flux inequality was in accordance with the hydrologic inequality, given the biogeochemical equality prevails in the landscape. The Lorenz curve and G in association with spatial maps are useful tools to guide landscape-scale management strategies to reduce N2O emissions, as well as spatial and temporal monitoring of N2O emissions.Based on the critical threshold of [theta]A

Download or read book Nitrous Oxide Production in Natural and Agricultural Ecosystem Soils of Wisconsin written by Lewis L. Goodroad and published by . This book was released on 1983 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Foundations of Restoration Ecology written by Donald A. Falk and published by Island Press. This book was released on 2013-03-19 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the practical application of ecological restoration continues to grow, there is an increasing need to connect restoration practice to areas of underlying ecological theory. Foundations of Restoration Ecology is an important milestone in the field, bringing together leading ecologists to bridge the gap between theory and practice by translating elements of ecological theory and current research themes into a scientific framework for the field of restoration ecology. Each chapter addresses a particular area of ecological theory, covering traditional levels of biological hierarchy (such as population genetics, demography, community ecology) as well as topics of central relevance to the challenges of restoration ecology (such as species interactions, fine-scale heterogeneity, successional trajectories, invasive species ecology, ecophysiology). Several chapters focus on research tools (research design, statistical analysis, modeling), or place restoration ecology research in a larger context (large-scale ecological phenomena, macroecology, climate change and paleoecology, evolutionary ecology). The book makes a compelling case that a stronger connection between ecological theory and the science of restoration ecology will be mutually beneficial for both fields: restoration ecology benefits from a stronger grounding in basic theory, while ecological theory benefits from the unique opportunities for experimentation in a restoration context. Foundations of Restoration Ecology advances the science behind the practice of restoring ecosystems while exploring ways in which restoration ecology can inform basic ecological questions. It provides the first comprehensive overview of the theoretical foundations of restoration ecology, and is a must-have volume for anyone involved in restoration research, teaching, or practice.

Download or read book Land use Landform and Seasonal dependent Changes in Microbial Communities and Their Impact on Nitrous Oxide Emission Activities written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The greenhouse gas nitrous oxide (N2O) is produced mainly by the microbial processes of nitrification and denitrification. I hypothesized that microbial community structure (composition and abundance) is linked to differences in soil N2O emissions from these two processes. Microbial community composition (type and number of nitrifier and denitrifier genotypes), abundance and N2O emission activity were determined and compared for soils from two landscapes characteristic of the North American prairie pothole region (cultivated vs. uncultivated wetlands). The landscape difference in composition of individual microbial communities was not predictive of soil N2O emissions, indicating that there is redundancy in each microbial community in relation to N2O emission activities. However, community factors influenced the pattern and distribution of N2O emission from the soils of the study site. For example, nitrification was the dominant N2O emitting process for soils of all landforms. However, neither nitrifier amoA abundance nor community composition had predictive relationships with nitrification associated N2O emissions. This lack of relationship may be a consequence of using amoA as the gene target to characterize nitrifiers. For denitrifying bacteria, there was a temporal relationship between community composition and N2O emissions. However, this may be related to the change in water-filled pore space over time. Alternatively, the presence of fungi can be linked directly to N2O emissions from water accumulating landform elements. Under hypoxic conditions, there may be two fungal pathways contributing to N2O release: fungal denitrification via P450nor and fungal heterotrophic nitrification. Results suggest that the relative importance of these two processes is linked to root exudates such as formate. It is the interaction between the seasonal fluctuations of the microbial and environmental factors that determine the level of N2O emissions from soils.

Download or read book Measured and Daycent Simulated Nitrous Oxide Emissions from Soil Planted to Corn in Dairy Cropping Systems written by Maria Ponce De Leon Jara and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Crop rotations, organic nutrient amendments, reduced tillage practices, and integration of cover crops are practices that have the potential to increase the sustainability of crop production, yet they also impact nitrous oxide (N2O) emissions. Agricultural soil management has been estimated to contribute 79% of the total N2O emissions in the U.S., and inorganic nitrogen (N) fertilization is one of the main contributors. Nitrous oxide is a potent greenhouse gas that has a global warming potential which is approximately 298 times that of carbon dioxide (CO2) over a 100-year period and is currently the dominant ozone-depleting substance. Few studies have assessed the effects of organic N amendments on direct N2O within the context of a typical dairy forage cropping system. Most research has been limited to studying the effects of one or two sources of N inputs on N2O emissions; however, dairy forage cropping systems often apply manure and have more than two N sources that likely both contribute to N2O emissions. This study investigated how different dairy cropping practices that include differences in crop residues, N inputs (dairy manure and inorganic fertilizer), timing of N amendment applications and environmental conditions influenced N2O emissions from no-till soil planted to corn (Zea mays L.). A two-year field study was carried out as part of the Pennsylvania State Sustainable Dairy Cropping Systems Experiment, where corn was planted following annual grain crops, perennial forages, and a green manure legume crop; all were amended with dairy manure. In the corn-soybean (Glycine max (L.) Merr.) rotation, N sources (dairy manure and inorganic fertilizer) and two methods of manure application (broadcasted and injected) were also compared.Chapter 1 reviews the scientific literature; describing the biotic and abiotic processes of N2O production in soils, summarizing current research on N2O emissions in agricultural systems, and emphasizing the main management and environmental drivers contributing to the emissions. This chapter reviews methods for matching N supply with crop demand, coupling N flow cycles, using advanced fertilizer techniques, and optimizing tillage management. Also, the applicability and limitations of current research to effectively reduce N2O emissions in a variety of regions are discussed.Chapter 2 analyzes the effect of corn production management practices and environmental conditions contributing to N2O in the Pennsylvania State Sustainable Dairy Cropping Systems Experiment. Significantly higher N2O emissions were observed 15-42 days after manure injection and 1-4 days after mid-season UAN application. Manure injection had 2-3 times greater potential for N2O emissions compared to broadcast manure during this time period. Integration of legumes and grasses in the cropping system reduced inorganic fertilizer use compared to soybean with manure or UAN, however, direct N2O emissions were not reduced. The Random Forest method was used to identify and rank the predictor variables for N2O emissions. The most important variables driving N2O emissions were: time after manure application, time after previous crop termination, soil nitrate, and moisture. These field research results support earlier recommendations for reducing N losses including timing N inputs close to crop uptake, and avoiding N applications when there is a high chance of precipitation to reduce nitrate accumulation in the soil and potential N losses from denitrification.Chapter 3 reports the comparison of N2O fluxes predicted with the biogeochemical model DAYCENT compared to measured data from the two-year dairy cropping systems study. Daily N2O emissions simulated by DAYCENT had between 41% and 76% agreement with measured daily N2O emissions in 2015 and 2016. DAYCENT overestimated the residual inorganic N fertilizer impact on N2O emissions in the corn following soybean with inorganic fertilizer and broadcast manure. Comparisons between DAYCENT simulated and measured N2O fluxes indicate that DAYCENT did not represent well organic N amendments from crop residues of perennials and legume cover crops, or manure application in no-till dairy systems. DAYCENT was generally able to reproduce temporal patterns of soil temperature, but volumetric soil water contents (VSWC) predicted by DAYCENT were generally lower than measured values. After precipitation events, DAYCENT predicted that VSWC tended to rapidly decrease and drain to deeper layers. Both the simulated and measured soil inorganic N increased with N fertilizer addition; however, the model tended to underestimate soil inorganic N concentration in the 0-5 cm layer. Our results suggest that DAYCENT overestimated the residual N impact of inorganic fertilizer on N2O emissions and mineralization of organic residues and nitrification happened faster than DAYCENT predicted. Chapter 4 highlights the impact of manure injection and the importance of timing organic N amendments from manures and/or crop residue with crop N uptake to mitigate N2O emissions. More research is needed to better understand the tradeoffs of these strategies in no till dairy cropping systems to help farmers in their operational management decisions. Improving the parametrization of DAYCENT for dairy cropping systems in no-till systems with high surface legume crop residues from perennials and cover crops, will make the model a more useful tool for testing different mitigation scenarios for farmers and policy-designer decision making.

Download or read book Effects of Management on Selected Soil Properties and Nitrous Oxide Fluxes in Dairy Cropping Systems written by Emily Paige Ball and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates selected soil properties and management decisions and their effect on nitrous oxide (N2O) emissions from agricultural soils. Nitrate, an inorganic form of N, is extremely mobile in soils, making it susceptible to loss through processes like denitrification. Denitrification is an anaerobic microbial process that reduces nitrate to N2 or incompletely to N2O, a potent greenhouse gas. The experimental site for this research was the Sustainable Dairy Cropping System (SDCS) located at Penn States Agronomy Farm. Chapter one is a review of the literature on nitrogen (N) cycling in agriculture, N loss pathways and the management and environmental factors affecting denitrification. This process is driven by soil properties, nitrate availability, and other factors. A prior study in this experiment in 2015 and 2016 found that the driving factors for N2O emissions in some of the same treatments were explained by days after manure application, growing degree days (GDD), and manure rate.Research on the effects of prior crop and management on N2O emissions in a typical PA dairy cropping system is described in chapter two. Labile carbon, total carbon, inorganic N species, and other environmental data were measured to determine their impact on measured N2O fluxes in 2017 and 2018. However, the measured soil and environmental properties in this experiment were not able to explain the observed patterns in N2O emissions through a regression analysis. The highest N2O fluxes were measured in 2018 in Corn after two years of Alfalfa (Medicago sativa) + Orchardgrass (Dactylis glomerata). Cumulative emissions were more than six times higher than those measured in treatments without a winter cover in the same year.Based on findings in 2017, chapter three investigates the impact of termination timing of Alfalfa+Orchardgrass on spring N2O fluxes and soil properties in 2018. This management decision is becoming more popular in the Northeast as spring conditions become wetter, making the proper timing of spring management events difficult. The findings from this experiment are promising for farmers interested in adopting this management practice as yields did not significantly differ from the subsequent corn crop and although they did not significantly differ, spring cumulative emissions from the spring terminated treatment were more than three times those from the fall terminated treatment. Because N2O emissions were not measured in the fall, however, the comparison of the two treatments in this study was not comprehensive.Chapter four described an investigative study on redox potentials in unsaturated agricultural soils. Equipment constraints and spatial variability made understanding and interpreting these results difficult. There were diurnal trends exhibited in some treatments, reflecting diurnal changes in soil moisture but not others. There also seemed to be stratification in depth, although this trend also differed across treatments. Overall, there is evidence that different crops can facilitate different redox environments and in turn, different microbial processes. However, more research and equipment advances need to take place before redox potential could be considered a useful indicator of microbial processes in unsaturated soils.Finally, the conclusions summarized the major findings of each of these experiments and discussed the impact of sustainable management practices on improving soil resiliency. Implementing sustainable practices like cover cropping and no-till can improve soil, although trade-offs of higher N2O emissions may result. Further research on these practices and their impact on soil properties is necessary as the effects of climate change are becoming more apparent.

Download or read book Nitrous Oxide Emissions written by Miguel Andres Arango Argoti and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen is critical for plant growth and is a major cost of inputs in production agriculture. Too much nitrogen (N) is also an environmental concern. Agricultural soils account for 85% of anthropogenic N2O which is a major greenhouse gas. Management strategies for N fertilization and tillage are necessary for enhancing N use efficiency and reducing negative impacts of N to the environment. The different management practices induce changes in substrate availability for microbial activity that may result in increasing or reducing net N2O emitted from soils. The objectives of this research were to (1) integrate results from field studies to evaluate the effect of different management strategies on N2O emissions using a meta-analysis, (2) quantify N2O-N emissions under no-tillage (NT) and tilled (T) agricultural systems and the effect of different N source and placements, (3) perform sensitivity analysis, calibration and validation of the Denitrification Decomposition (DNDC) model for N2O emissions, and (4) analyze future scenarios of precipitation and temperature to evaluate the potential effects of climate change on N2O emissions from agro-ecosystems in Kansas. Based on the meta-analysis there was no significant effect of broadcast and banded N placement. Synthetic N fertilizer usually had higher N2O emission than organic N fertilizer. Crops with high N inputs as well as clay soils had higher N2O fluxes. No-till and conventional till did not have significant differences regarding N2O emissions. In the field study, N2O-N emissions were not significantly different between tillage systems and N source. The banded N application generally had higher emissions than broadcasted N. Slow release N fertilizer as well as split N applications reduced N2O flux without affecting yield. Simulations of N2O emissions were more sensitive to changes in soil parameters such as pH, soil organic carbon (SOC), field capacity (FIELD) and bulk density (BD), with pH and SOC as the most sensitive parameters. The N2O simulations performed using Denitrification Decomposition model on till (Urea) had higher model efficiency followed by no-till (compost), no-till (urea) and till (compost). At the regional level, changes in climate (precipitation and temperature) increased N2O emission from agricultural soils in Kansas. The conversion from T to NT reduced N2O emissions in crops under present conditions as well as under future climatic conditions.

Download or read book Soil Nitrous Oxide Emissions from Agriculture in a Changing Global Environment written by Charlotte Decock and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Agricultural soils encompass one of the major sources of anthropogenic nitrous oxide (N2O), a potent greenhouse gas and stratospheric ozone depleting substance. Therefore, accurate prediction of N2O emissions from soils and development of effective mitigation strategies are pertinent. However, the scientific understanding of mechanisms underlying N2O emissions is limited, in part, by the lack of suitable methods to assess sources of N2O, especially under field conditions and in undisturbed soil cores. In this dissertation, two ecological applications of source-partitioning N2O were considered: (1) the feedback of N2O emissions to elevated atmospheric CO2 and tropospheric O3 and (2) mechanisms underlying N2O emissions during a simulated rainfall event in a tomato cropping system in California. Furthermore, four methods were evaluated for their utility in source-partitioning N2O with minimal disturbance of the system: (1) tracing of added 15N enriched NH4 and/or NO3− to N2O, (2) use of natural abundance 15N of N2O and its precursors, (3) measuring the intramolecular distribution of 15N in N2O, expressed as site preference (SP), and (4) determining relationships between natural abundance 18O and 15N. Method comparisons elucidated that the use of isotope models that include all natural abundance isotopes of N2O and its precursors and uncertainty deductions for isotope fractionation factors to estimate N transformation rates and sources of N2O during peak N2O emissions is the most promising approach to improve our understanding of mechanisms underlying N2O emissions with minimal sampling-associated disturbance of the system. Various approaches to study sources of N2O and N-cycling suggested that elevated CO2 and O3 will unlikely cause a feedback on global climate change through altered N2O emissions in soybean agroecosystems in the Midwestern USA. Furthermore, elevated CO2 decelerated, whereas elevated O3 accelerated N-cycling if integrated over longer time scales. In a California tomato cropping system, N2O reduction to N2 decreased progressively as soil dried out following wetting up. Overall, this dissertation illustrates the added benefit of studying mechanisms underlying N2O emissions in addition to field N2O fluxes per se and encourages further research to source-partition N2O emissions and its needed methodology to understand N2O responses of agroecosystems in a changing global environment.

Download or read book Recovery of Whole Soil Conditions Through Restoration from Agriculture and Its Role in Mediating Plant plant Competition written by Drew Austin Scott and published by . This book was released on 2015 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: The tallgrass prairie has been severely reduced in size, making restoration important to maintain communities and functions of this ecosystem. A chronosequence approach was used to determine recovery of physical and biological soil properties. The recovery models of soil properties provided information to explain the variation in total C stock of the whole soil. Recovery models also provided information to design a competition experiment based on variation in whole soil conditions with land use history. The filter framework hypothesis is a useful concept for examining tallgrass prairie restoration; the theory states only a subset of species in the region will be able to establish in a specific location due to abiotic and biotic filters. With this theory in mind, I explored the influence of whole soil conditions as affected by land use history (cultivation/restoration) and how these conditions altered plant-plant competition dynamics of a dominant grass was studied. Belowground plant biomass recovers with cessation of tillage and restoration back to prairie, providing an organic matter source for microbial populations to recover and soil macroaggregates to form. This has potential to increase C sequestration in soils and decrease nitrous oxide efflux from soils. Intact 5.5 cm dia cores were collected to a depth of 10 cm in each field to determine physical and biological soil properties. Belowground plant, microbial community, and soil structure properties were modeled to recover coinciding with an increase in total C stock of the whole soil. Structural equation modeling revealed that soil structure physically protecting organic matter explained the most variation in soil carbon sequestration with restoration. Most of the total C was contained within the macroaggregate size fraction; within this fraction most of that C is within the microaggregates within macroaggregates fraction. Soil structure is critical for recovery of soil carbon stocks and the microaggregate within macroaggregate fraction is the best diagnostic of sequestered C. ANCOVA results indicate that while the slopes of nitrous oxide efflux rates did not differ, cumulative efflux differed, though this was not related to time since restoration. Dominant grasses, such as Andropogon gerardii, can exclude subordinate species from grassland restorations. Thus, understanding changes in competition dynamics of dominant grasses could help maintain richness in grassland restorations. There may be changes in competition dynamics with whole soil conditions affected by land use history (cultivation/restoration) as plant available nutrients will decrease, microbial populations will increase, and soil structure will improve with restoration from cultivation to prairie. Using 4 soil treatments of varying land use history with four species treatments, to determine if effects are general or species specific, pairwise substitution competition experiments were conducted. Relative A. gerardii response to competition was compared among soil and species treatments using competition intensity and competition importance indices utilizing final plant biomass, relative growth rate based on maximum height, and net absolute tiller appearance rate. The experiment was conducted over 18 weeks, allowing A. gerardii to flower. A significant intensity result and significant importance results utilizing biomass measurements indicated that the 16 year restored prairie soil cause A. gerardii to be a relatively better competitor against forbs than in all other soils except for cultivated soil, likely due to positive plant-soil feedbacks. Significant importance results utilizing tiller appearance rate indicated that the cultivated and 3 year restored prairie soil caused A. gerardii to be a relatively better competitor than in the 16 year restored and never cultivated native prairie soils, likely due to changes in whole soil conditions related to land use history. There were only general soil effects, as soil treatments did not interact with species treatments. A. gerardii was a relatively better competitor against non-leguminous forbs, indicating that legumes are a better competitor for a limiting nutrient than A. gerardii or that this species is not in direct competition with legumes.

Download or read book Biodiversity and Ecosystem Function written by Ernst-Detlef Schulze and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: The biota of the earth is being altered at an unprecedented rate. We are witnessing wholesale exchanges of organisms among geographic areas that were once totally biologically isolated. We are seeing massive changes in landscape use that are creating even more abundant succes sional patches, reductions in population sizes, and in the worst cases, losses of species. There are many reasons for concern about these trends. One is that we unfortunately do not know in detail the conse quences of these massive alterations in terms of how the biosphere as a whole operates or even, for that matter, the functioning of localized ecosystems. We do know that the biosphere interacts strongly with the atmospheric composition, contributing to potential climate change. We also know that changes in vegetative cover greatly influence the hydrology and biochemistry ofa site or region. Our knowledge is weak in important details, however. How are the many services that ecosystems provide to humanity altered by modifications of ecosystem composition? Stated in another way, what is the role of individual species in ecosystem function? We are observing the selective as well as wholesale alteration in the composition of ecosystems. Do these alterations matter in respect to how ecosystems operate and provide services? This book represents the initial probing of this central ques tion. It will be followed by other volumes in this series examining in depth the functional role of biodiversity in various ecosystems of the world.

Download or read book The Soils of Ireland written by Rachel Creamer and published by Springer. This book was released on 2018-03-29 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of pedology in Ireland. It describes the main soil types of the country, their functions, ecological use, and the conditions to which they were subjected associated with management over time. In addition, it presents a complete set of data, pictures and maps, including benchmark profiles. Factors involved in soil formation are also discussed, making use of new, unpublished data and elaborations. The book was produced with the support and sponsorship of Teagasc, The Agriculture and Food Development Authority, Ireland and the Irish Environmental Protection Agency.

Download or read book Forest and Rangeland Soils of the United States Under Changing Conditions written by Richard V. Pouyat and published by Springer Nature. This book was released on 2020-09-02 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book synthesizes leading-edge science and management information about forest and rangeland soils of the United States. It offers ways to better understand changing conditions and their impacts on soils, and explores directions that positively affect the future of forest and rangeland soil health. This book outlines soil processes and identifies the research needed to manage forest and rangeland soils in the United States. Chapters give an overview of the state of forest and rangeland soils research in the Nation, including multi-decadal programs (chapter 1), then summarizes various human-caused and natural impacts and their effects on soil carbon, hydrology, biogeochemistry, and biological diversity (chapters 2–5). Other chapters look at the effects of changing conditions on forest soils in wetland and urban settings (chapters 6–7). Impacts include: climate change, severe wildfires, invasive species, pests and diseases, pollution, and land use change. Chapter 8 considers approaches to maintaining or regaining forest and rangeland soil health in the face of these varied impacts. Mapping, monitoring, and data sharing are discussed in chapter 9 as ways to leverage scientific and human resources to address soil health at scales from the landscape to the individual parcel (monitoring networks, data sharing Web sites, and educational soils-centered programs are tabulated in appendix B). Chapter 10 highlights opportunities for deepening our understanding of soils and for sustaining long-term ecosystem health and appendix C summarizes research needs. Nine regional summaries (appendix A) offer a more detailed look at forest and rangeland soils in the United States and its Affiliates.

Download or read book Negative Emissions Technologies and Reliable Sequestration written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-04-08 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.

Download or read book Ecosystem Services Derived from Wetland Conservation Practices in the United States Prairie Pothole Region with an Emphasis on the U S Department of Agriculture Conservation Reserve and Wetlands Reserve Programs written by Robert A. Gleason and published by Geological Survey (USGS). This book was released on 2008 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Foundations of Restoration Ecology written by Society for Ecological Restoration International and published by Island Press. This book was released on 2016-11 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Society for Ecological Restoration"--Cover.