Determining how factors such as disturbance and nutrient availability affect species diversity in a community has been a major goal of community ecology. The purpose of this study was to look at how species diversity and composition of soil bacterial communities are affected by nutrient addition and disturbance. I characterized soil microbial communities at the long-term ecological research site at the West Research Campus (WRC) located in Pitt County, NC. Briefly, DNA extracted from soils was analyzed using amplicon sequencing of the 16S ribosomal RNA gene. The Illumina Platform was used to sequence the bacterial DNA from each sample, and the Mothur Pipeline was used to analyze the DNA sequences. I hypothesized that changes in nutrient availability and disturbance would impact soil microbial community composition and diversity through direct and indirect effects mediated by plant-soil interactions. My research complemented previous work carried out in the WRC determining the effects of nutrient addition and disturbance on plant communities. Analysis of 2013 plant data showed that mowing increased plant species richness, and fertilization decreased plant species richness significantly. The experimental treatments as well as the proximity of the blocks to a drainage ditch all had significant effects on plant community composition. Analysis of the microbial community data showed that both fertilization and mowing significantly increased mean species richness. Relative abundance microbial community composition varied significantly due to the proximity of the blocks to the ditch. Presence/absence microbial community analyses showed significant effects of the treatments, as well as ditch proximity on microbial composition differences. Also, unknown microbial communities showed significant variation of the communities due to the treatments. The results of the presence/absence analysis and the unknown microbial community analysis show the importance of rare taxa and unknown microbial communities to the differences in composition of our soil microbial communities. Analysis of the soil chemical and physical data showed very little variation due to the treatments. This study will contribute to our understanding of how both plant and soil bacterial community diversity are affected by anthropogenic nutrient addition and disturbances. Maintaining diversity is important for ecosystem stability and functioning.

There can be little doubt that there are truly colossal challenges associated with providing food, fibre and energy for an expanding world population without further accelerating already rapid rates of biodiversity loss and undermining the ecosystem processes on which we all depend. These challenges are further complicated by rapid changes in climate and its additional direct impacts on agriculture, biodiversity and ecological processes. There are many different viewpoints about the best way to deal with the myriad issues associated with land use intensification and this book canvasses a number of these from different parts of the tropical and temperate world. Chapters focus on whether science can suggest new and improved approaches to reducing the conflict between productive land use and biodiversity conservation. Who should read this book? Policy makers in regional, state and federal governments, as well as scientists and the interested lay public.

The effects of global climate change are accelerated and more pronounced in northern regions, and Alaska is at the forefront of that change. Permafrost, which underlies much of the Alaskan landscape, is rapidly thawing and degrading leading to shifts in hydrology, soil chemistry, and nutrient availability. As permafrost thaws, soil microbial communities have the potential to be influenced taxonomically and functionally. However, it is unclear how active layer microbial communities, which play a role in plant-microbe interactions, are affected by increasing soil disturbance, and how soil microbiomes can influence above ground plant communities. In this study, I aimed to understand how soil microbial communities from Interior Alaska are affected by increasing disturbance, and how they in turn drive the productivity of several plants found in boreal regions. Here I used a growth experiment and found that plant productivity was affected by the disturbance level of the microbial inoculant. Plants grown in soils inoculated with microbes associated with disturbed soils demonstrated significantly decreased productivity compared to plants inoculated with microbes from undisturbed soils. Through metagenomic sequencing, I observed broad scale shifts in community membership across the gradient of soil disturbance. I then continued to characterize the microbial communities used as inoculants in the greenhouse growth experiment through 16S rRNA amplicon sequencing. Microbial communities from disturbed soils were significantly more diverse than those from undisturbed soils, and the beta diversity of communities varied significantly based on the disturbance level. We found that within disturbance level community variation can be used to predict plant growth of bog blueberry, low-bush cranberry, and Labrador tea once the disturbance passes a threshold. These results suggest that as active layer microbial communities are affected by climate-driven soil disturbance, above ground plant communities may demonstrate decreased productivity, and consequently, decreased ecosystem health as the Arctic continues to warm.

The globally important nature of wetland ecosystems has led to their increased protection and restoration as well as their use in engineered systems. Underpinning the beneficial functions of wetlands are a unique suite of physical, chemical, and biological processes that regulate elemental cycling in soils and the water column. This book provides an in-depth coverage of these wetland biogeochemical processes related to the cycling of macroelements including carbon, nitrogen, phosphorus, and sulfur, secondary and trace elements, and toxic organic compounds. In this synthesis, the authors combine more than 100 years of experience studying wetlands and biogeochemistry to look inside the black box of elemental transformations in wetland ecosystems. This new edition is updated throughout to include more topics and provide an integrated view of the coupled nature of biogeochemical cycles in wetland systems. The influence of the elemental cycles is discussed at a range of scales in the context of environmental change including climate, sea level rise, and water quality. Frequent examples of key methods and major case studies are also included to help the reader extend the basic theories for application in their own system. Some of the major topics discussed are: Flooded soil and sediment characteristics Aerobic-anaerobic interfaces Redox chemistry in flooded soil and sediment systems Anaerobic microbial metabolism Plant adaptations to reducing conditions Regulators of organic matter decomposition and accretion Major nutrient sources and sinks Greenhouse gas production and emission Elemental flux processes Remediation of contaminated soils and sediments Coupled C-N-P-S processes Consequences of environmental change in wetlands# The book provides the foundation for a basic understanding of key biogeochemical processes and its applications to solve real world problems. It is detailed, but also assists the reader with box inserts, artfully designed diagrams, and summary tables all supported by numerous current references. This book is an excellent resource for senior undergraduates and graduate students studying ecosystem biogeochemistry with a focus in wetlands and aquatic systems.

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.

This volume explores current knowledge and methods used to study soil organisms and to attribute their activity to wider ecosystem functions. Biodiversity not only responds to environmental change, but has also been shown to be one of the key drivers of ecosystem function and service delivery. Soil biodiversity in tree-dominated ecosystems is also governed by these principles, the structure of soil biological communities is clearly determined by environmental, as well as spatial, temporal and hierarchical factors. Global environmental change, together with land-use change and ecosystem management by humans, impacts the aboveground structure and composition of tree ecosystems. Due to existing knowledge of the close links between the above- and belowground parts of terrestrial ecosystems, we know that soil biodiversity is also impacted. However, very little is known about the nature of these impacts; effects on the overall level of biodiversity, the magnitude and diversity of functions soil biodiversity generates, but also on the present and future stability of tree ecosystems and soils. Even though much remains to be learned about the relationships between soil biodiversity and tree ecosystem functionality, it is clear that better effort needs to be made to describe and understand key processes which take place in soils and are driven by soil biota.