Browsing by Subject "Wetlands"

Now showing 1 - 5 of 5

Considering the importance of wetlands to hunter-gatherer adaptation : a microbotanical investigation of Late Pleistocene plant-use in the Eastern Levant
(2015-08) Nicolaides, Monica Lorelle; Rosen, Arlene Miller; Denbow, James R.; Wade, Mariah D.; Butzer, Karl W.; Olszewski, Deborah I.
The distribution and composition of ecological opportunities had a tremendous impact on Late Upper Palaeolithic to Middle Epipaleolithic (ca. 28-14.5 ka cal. BP) (Late Pleistocene) hunter-gatherers, influencing the ways they chose to use, modify and manage the changing Levantine landscape through and after the Last Glacial Maximum (ca. 28-19 ka cal. BP). The main objective of this dissertation is to employ phytolith and micro-charcoal analysis to explore through direct evidence, the long-term patterns of Late Pleistocene hunter-gatherer plant-use in the Eastern Levant. The phytolith data presented in this dissertation demonstrates clearly that wetlands are vital to understanding Late Pleistocene hunter-gatherer adaptations in the Eastern Levant during the late Pleistocene. This new direct archaeobotanical evidence shows that Late Pleistocene hunter-gatherers employed flexible local systems of plant-use that focused on wetland resources. Through their exploitation of anthropogenically sensitive phytolittoral resources, Late Pleistocene hunter-gatherers may have facilitated the development and expansion of those resources and contributed to the social and ecological feedbacks that aided the ‘upward mobility’ of wetland resources. In providing a dependable food and craft resource repository, wetland plant resources may have facilitated increasingly sedentary adaptations in certain locales and perhaps permitted increasing use of risky grass and cereal resources. This understanding of Late Pleistocene plant-use and human-environment dynamics veers significantly from previous perspectives on hunter-gatherer plant-use in the region. Firstly, in considering the local ecological opportunities, this work emphasizes the complexity of gathering strategies and the choices hunter-gatherers faced in the Late Pleistocene. Secondly, by seeking a new ethnographic analog in the American Great Basin, a region defined by its characteristic wetland/dryland landscape, it was possible to hypothesize about the many types of hunter-gatherer wetland adaptations in the Eastern Levant. Thirdly, by employing phytolith analysis a different picture of plant-use emerges from that which focuses on macrobotanical remains alone. Moreover, because macrobotanical remains are so rare in most Epipaleolithic contexts, this phytolith data constitutes the most complete botanical record for this important period in the Eastern Levant. This new perspective helps shift the emphasis from cereal and small-seeded grass (SSG) use and the broad-spectrum revolution (BSR) narrative that has overbearingly dominated our understanding of Late Pleistocene hunter-gatherers. Lastly, informed by an understanding of human-environment interactions based in Historical Ecology and Human Niche Construction (HNC), this dissertation recognizes that Late Pleistocene hunter-gatherers did not just react to their environments, but created and modified their environments. This research critically reconsiders the way we see hunter-gatherers in the prehistory of the Levant.
Effects of simulated inundation on wetland methane flux predictions for the southeastern U.S.
(2015-08) Resovsky, Alex Edward; Yang, Zong-liang; Shanahan, Timothy M; Breecker, Daniel O
This work provides an overview of factors that influence methane emissions from natural wetlands in the southeastern U.S. at seasonal and interannual timescales. It then examines simulations using CLM4Me, a methane biogeochemistry model run within CESM, through comparison with recently compiled flux estimations from remote sensing data. In addition, we assess how seasonal methane flux simulations in CLM4Me are affected by the use of alternative estimates of inundated land fraction. Inundation predictions are provided by DYPTOP, a TOPMODEL implementation which can be used to simulate the dynamics of wetland spatial distribution. Results may aid in future model development and in understanding the role of subtropical and temperate North American wetlands under future climate projections.
Enhanced Migratory Waterfowl Distribution Modeling by Inclusion of Depth to Water Table Data
(Public Library of Science, 2012-01-17) Kreakie, Betty J.; Fan, Ying; Keitt, Timothy H.
In addition to being used as a tool for ecological understanding, management and conservation of migratory waterfowl rely heavily on distribution models; yet these models have poor accuracy when compared to models of other bird groups. The goal of this study is to offer methods to enhance our ability to accurately model the spatial distributions of six migratory waterfowl species. This goal is accomplished by creating models based on species-specific annual cycles and introducing a depth to water table (DWT) data set. The DWT data set, a wetland proxy, is a simulated long-term measure of the point either at or below the surface where climate and geological/topographic water fluxes balance. For species occurrences, the USGS' banding bird data for six relatively common species was used. Distribution models are constructed using Random Forest and MaxEnt. Random Forest classification of habitat and non-habitat provided a measure of DWT variable importance, which indicated that DWT is as important, and often more important, to model accuracy as temperature, precipitation, elevation, and an alternative wetland measure. MaxEnt models that included DWT in addition to traditional predictor variables had a considerable increase in classification accuracy. Also, MaxEnt models created with DWT often had higher accuracy when compared with models created with an alternative measure of wetland habitat. By comparing maps of predicted probability of occurrence and response curves, it is possible to explore how different species respond to water table depth and how a species responds in different seasons. The results of this analysis also illustrate that, as expected, all waterfowl species are tightly affiliated with shallow water table habitat. However, this study illustrates that the intensity of affiliation is not constant between seasons for a species, nor is it consistent between species.
The 2015 Clean Water Rule's impact on oil and gas development in the Bakken Shale
(2016-05) Oliver, Mark Moore; Butler, John C. (Clinical associate professor); Kreitler, Charles W.; Fisher, William L
The 2015 Clean Water Rule (CWR) amended the definition of aquatic resources under the federal jurisdiction of the Clean Water Act (CWA). Jurisdiction is re-asserted over a specified portion of aquatic resources legally designated as isolated. The “isolated waters” stipulations apply to the Prairie Pothole Region (PPR), a region recently threatened by heightened oil and gas activity associated with the economic productivity of the underlying Bakken shale. The architects of the CWR claim it does not dramatically expand the jurisdictional scope of the CWA. The Oil and Gas Industry refutes this notion claiming the expansionary nature of the CWR will dramatically increase indirect costs associated with the CWA Section 404 dredge and fill provisions, crippling production in select regions. This study incorporates GIS spatial analysis with predictive modeling tools to determine the CWR’s impact to oil and gas development in the Bakken Shale portion of the PPR. More specifically, this study estimates and characterizes the extent of geographically isolated waters in the study region, determines the scope of jurisdiction within the study region based upon the CWR’s stipulations, and forecasts the economic impact to the oil and gas industry based upon the industry’s development footprint from 2006-2014. Results reaffirm the substantial amount of aquatic resources located within the study region. Furthermore, a significant portion of those resources will become jurisdictional under the new rule. However, the impacts to oil and gas industry are not expected to parallel the increase in jurisdiction. Development patterns over the last decade reveal an insignificant number of permanent impacts to wetlands associated with the development of 4,000 wells. Instead, the estimated increase in jurisdiction will increase the importance of incorporating environmental awareness measures into current operations to alleviate inevitable costs associated with delays, mitigation, and compensation, all while ensuring the industry’s long-term sustainability.
Wetland agroecoystems in the Maya Lowlands of Belize : LiDAR and multi-proxy environmental change
(2018-09-14) Krause, Samantha Marie; Beach, Timothy Paul; Luzzadder-Beach, Sheryl; Doolittle, William; Rosen, Arlene; Valdez, Frez
Globally, scholars have identified wetlands as critical environments for global carbon storage, water filtration, biodiversity, and many other ecosystem functions. Despite their importance, too few studies have focused on wetlands in the tropical Americas. This dissertation provides new and innovative knowledge on the extent and character of prehistoric indigenous wetland agricultural systems in the Maya Lowlands of Belize by exploring wetland development and paleoenvironmental change over the course of the late Holocene. The overall results of this project are as follows: provide new information and understanding of never before researched wetland agroecosystems; 2. determine the extent of human and environmental interaction and regional climate history in this crucial zone of the Neotropics, 3: answer questions concerning the scale and types of Maya to modern wetland management over time; 4: offer greater awareness concerning contemporary landscape degradation within critical wetland systems in the face of future climate change scenarios, and 5. provide future resources for policy and management of American wetlands as a critical geographic area.