Physical Sciences and Mathematics Commons^™

Geomorphic Disturbance And Anthropogenic Modifications In Big Barren Creek, Mark Twain National Forest, Southeast Missouri, Rachael A. Bradley

MSU Graduate Theses

This study investigates the influence of human disturbance on channel conditions in Big Barren Creek. The Big Barren watershed drains 191 km2 of the Ozark Highlands in southeast Missouri. Several segments of the creek have been channelized by levee construction and gravel mining. Approximately 27.2 km of the main stem of Barren Creek were assessed for 13 photo-years ranging from 1939 to 2014. Geomorphic classifications using channel conditions in aerial photographs and field observations were used to evaluate patterns of disturbance. While 52% of the creek is managed by private landowners, 81% of disturbed length occurs on private lands. Further, …

Modeled Co2 Emissions From Coastal Wetland Transitions To Other Land Uses: Tidal Marshes, Mangrove Forests, And Seagrass Beds, Catherine E. Lovelock, James W. Fourqurean, James T. Morris

Faculty Publications

The sediments of coastal wetlands contain large stores of carbon which are vulnerable to oxidation once disturbed, resulting in high levels of CO2 emissions that may be avoided if coastal ecosystems are conserved or restored. We used a simple model to estimate CO2 emissions from mangrove forests, seagrass beds, and tidal marshes based on known decomposition rates for organic matter in these ecosystems under either oxic or anoxic conditions combined with assumptions of the proportion of sediment carbon being deposited in either oxic or anoxic environments following a disturbance of the habitat. Our model found that over 40 years after …

Geomorphic Effects Of Logging Railbeds On An Ozarks Headwater Stream, Mark Twain National Forest, Missouri, Nickolas S. Bradley

MSU Graduate Theses

Geomorphic characteristics of headwater streams draining the Missouri Ozarks have not been studied as much as larger rivers in the region. Further, while the effects of historical logging on channel form and sediment supply have been identified, no studies have investigated the effects of logging tramways constructed along Ozark headwater rivers. This study examines the geomorphic characteristics and channel disturbances of Tram Hollow (1.67 km²) within the Mark Twain National Forest in the Ozark Highlands. The purpose of this study is to classify and quantify natural and disturbed channel morphology in Tram Hollow which has been affected by …

Plant Diversity Influences The Structure And Function Of A Restored Prairie And Its Responses To Added Disturbances, Rebecca Bevans

School of Natural Resources: Dissertations, Theses, and Student Research

As global warming, human conversion of natural landscapes to agricultural uses, and widespread biodiversity losses continue to alter the ecosystems we depend on, an understanding of the relationship between ecosystem structure, composition, and function is needed to maintain valuable ecosystem states and their associated functions. Research testing the limits of an ecosystem’s ability to maintain essential structure and functioning under disturbance conditions can aid in this goal.

In this study, I measured the relationship between plant diversity, community structure and functional traits, and their responses to added disturbances. I added disturbances representing those either caused or intensified by human activity …

Effects Of Industrial And Investigator Disturbance On Arctic-Nesting Geese, Brandt W. Meixell, Paul L. Flint

United States Geological Survey: Staff Publications

Oil and gas development on the Arctic Coastal Plain (ACP) of Alaska, USA may have effects on Arctic-nesting birds. To estimate effects of industrial activity and investigator disturbance on avian productivity, we monitored nests of greater white-fronted geese (Anser albifrons) with digital cameras and periodic nest visits during 2013–2014 at 2 sites on the ACP. A disturbed site was adjacent to human-made infrastructure and industrial clean-up activities initiated at the onset of the study and a control site was >2 km from sources of industrial disturbance. We assessed variation in estimates of incubation constancy, nest survival, and predator …

Impact Of Linear Disturbances On A Discontinuous Permafrost Peatland Environment, Michael Braverman

Theses and Dissertations (Comprehensive)

Permafrost is ground that remains at or below 0°C for at least two consecutive years (PIWP, 2012). In the continuous permafrost zone its thickness may exceed 300 m, in lower latitudes, permafrost thickness is progressively decreasing, its occurrence becomes discontinuous and eventually sporadic (PIWP, 2012). At the southern fringe of permafrost in northwestern Canada, just about few meters. In subarctic peatlands permafrost is one of the main elements governing the hydrological processes. Being very thin and with temperature just fractions of the degree below 0^oC, it is very vulnerable to any changes in soil temperature and water content. …