Soil microbial communities were examined in two chronosequences of reclaimed surface mine soil and in a chronosequence of previously burned sites to determine how these communities recover through time after disturbance. Phospholipid fatty acid (PLFA) methods for microbial community analysis were used to quantify microbial biomass, diversity, and abundance of specific microbial groups (gram positive bacteria, gram negative bacteria, fungi, arbuscular mycorrhizal fungi, and actinomycetes). Multivariate analysis of variance (MANOVA) and discriminant analysis (DA) were used to compare soil microbial communities and site environmental factors. The soil microbial community in sagebrush-grassland ecosystems disturbed by fire appeared to recover to similar levels of biomass and diversity as in unburned soil within 3 to 7 years. In the surface mine reclamation sites, microbial recovery was seen in 5 to 10 years after reclamation in sites dominated by sagebrush and within 14 years after reclamation in the sites dominated by cool season grasses. Plant community composition was found to have influences in soil microbial recovery. Microbial communities in soil under crested wheatgrass (Agropyron cristatum) recovered to greater biomass than did the communities associated with other plant species. Soil fungi appeared to be the most adversely affected by soil disturbance associated with surface mining than the other microbial groups examined, and they were also slow to recover after the initiation of reclamation. A general trend of recovery towards the undisturbed condition with reclamation age was found for all microbial groups after disturbance. Our data on microbial community recovery from fire and impacts of surface mining suggests that soil microbial communities are highly resilient to disturbances.

Microbial communities are ubiquitous in our world and play important roles in biogeochemical and ecosystems processes on Earth. The ability of these microbial communities to provide these different processes is frequently tied to their community structure, which can be thought of both in terms of membership (i.e. who is there) and the relative abundance of these members. Changes in environmental conditions often lead to changes in microbial community structure as well. Microbial communities are formed through the process of assembly, which in turn is driven by the four processes of 1) Selection 2) Dispersal 3) Drift and 4) Diversification. Understanding the relative importance of each of these processes in different systems is important for predicting how microbial communities will change in response to disturbances. This dissertation presents work that uses the coal fire in Centralia, PA as a model press disturbance for understanding soil microbial community responses to and recovery from disturbance. The experiments herein aim to shed light the relative roles of Selection, Dispersal, and Drift in governing these responses in soil microbial communities experience a temperature disturbance. An observation study of a chronosequence of fire disturbance in Centralia, PA is used to generate hypotheses as to the relative roles of Selection, Dispersal, and Drift in the assembly of soil microbial communities experiencing a temperature disturbance. Further, an in depth look at some of these communities using shotgun metagenomics is used to observe specific microbial traits and characteristics selected for by the temperature disturbance. Finally, a laboratory soil mesocosm warming experiment investigates the relative influence of Dispersal and dormancy in governing responses to and recovery from disturbance.

Biodiversity-the genetic variety of life-is an exuberant product of the evolutionary past, a vast human-supportive resource (aesthetic, intellectual, and material) of the present, and a rich legacy to cherish and preserve for the future. Two urgent challenges, and opportunities, for 21st-century science are to gain deeper insights into the evolutionary processes that foster biotic diversity, and to translate that understanding into workable solutions for the regional and global crises that biodiversity currently faces. A grasp of evolutionary principles and processes is important in other societal arenas as well, such as education, medicine, sociology, and other applied fields including agriculture, pharmacology, and biotechnology. The ramifications of evolutionary thought also extend into learned realms traditionally reserved for philosophy and religion. The central goal of the In the Light of Evolution (ILE) series is to promote the evolutionary sciences through state-of-the-art colloquia-in the series of Arthur M. Sackler colloquia sponsored by the National Academy of Sciences-and their published proceedings. Each installment explores evolutionary perspectives on a particular biological topic that is scientifically intriguing but also has special relevance to contemporary societal issues or challenges. This tenth and final edition of the In the Light of Evolution series focuses on recent developments in phylogeographic research and their relevance to past accomplishments and future research directions.

The Arthur M. Sackler Colloquia of the National Academy of Sciences address scientific topics of broad and current interest, cutting across the boundaries of traditional disciplines. Each year, four or five such colloquia are scheduled, typically two days in length and international in scope. Colloquia are organized by a member of the Academy, often with the assistance of an organizing committee, and feature presentations by leading scientists in the field and discussions with a hundred or more researchers with an interest in the topic. Colloquia presentations are recorded and posted on the National Academy of Sciences Sackler colloquia website and published on CD-ROM. These Colloquia are made possible by a generous gift from Mrs. Jill Sackler, in memory of her husband, Arthur M. Sackler.

This textbook is aimed at the majority of students, who need to quickly acquire a concise overview of soil science. Many current soil science textbooks still cater for a traditional student market where students embark on three years study in a narrow discipline. The growth in modular degree schemes has meant that soil science is now often taught as self-standing unit as part of broad based degree program. Students pursuing this type of course are increasingly reluctant to purchase expensive textbooks that are too detailed and often assume a scientific background. For those opting to specialise in soil science there are a variety of good textbooks to choose from. This short informative guide, will be particularly useful for students who do not possess a traditional scientific background, such as those studying geography, environment science, ecology and agriculture. Only textbook to cater for introductory courses in soil science. Provides an affordable concise overview of soil science. Learning exercises and chapter summaries enhance usability. Annotated suggestions for further reading. Based on proven and successful modular course structure. Emphasis on readability and interactive learning. No scientific background assumed.

[Truncated abstract] Recovery of soil nutrients, microbial populations and carbon (C) and nitrogen (N) cycling processes are critical to the success of rehabilitation following major ecosystem disturbance. Bauxite mining represents a major ecosystem disturbance to the jarrah (Eucalyptus marginata) forest in the south-west of Western Australia. Mining has created a mosaic of mined areas in various stages of succession surrounded by non-mined forest areas. Initial site preparations within rehabilitation areas such as contour ripping alter soil structure (creation of mound and furrows) and over time also influence the distribution of vegetation and litter. Current performance criteria developed by industry, government and other stakeholders have determined that before post-bauxite mined areas of jarrah forest can be integrated back into normal forest management practises they should be functional and demonstrate resilience to normal forest disturbances such as fire. Furthermore, resilience should be of a manner comparable to non-mined analogue forest sites. Currently little is known of the resilience of microbial communities and C and N cycling in rehabilitation sites to normal forest disturbances such as prescription burning. As such, before rehabilitated jarrah forests can be successfully integrated into broad scale forest management regimes, a more thorough knowledge of the potential impacts of burning practises on the soil microbial community and C and N cycling processes in these systems is required. ... While there are similar rates of C and N cycling the underlying microbial community structure was distinctly different; implying a high degree of functional redundancy with respect to C and N cycling. Differences in the C and N cycling and structure of the microbial communities were likely to be due to differences in soil environmental conditions (i.e. soil alkalinity/acidity, soil moisture) and C substrate availability which influence the physiological status of the microbial community and in turn are related to successional age of the forests. Results also suggest that the measurement of CLPP can be a useful approach for assessment of changes in the functional ability of microbial communities. However, the interpretation of how well these rehabilitation forests have recovered heterotrophic abilities was greatly affected by the methodological approach used (e.g. MicroRespTM or Degens and Harris, 1997). Importantly, results from Chapter 4 and 5 suggested that the effects of a moderate prescription fire on C and N processes, CLPP and microbial community structure of 18 year old rehabilitation forests are likely to be short-lived (

Remediation of contaminants caused by growing human civilization and industrialization is a serious environmental issue. Recent research has shown that soil microorganisms play an important role in remediating and improving disturbed ecosystems. This approach is eco-friendly and relatively less expensive. The present book covers the investigations carried out using microbes for restoration of degraded eco-systems. Please note: This volume is Co-published with New India Publishing Agency, New Delhi. Taylor & Francis does not sell or distribute the Hardback in India, Pakistan, Nepal, Bhutan, Bangladesh and Sri Lanka