Physical Sciences and Mathematics Commons^™

Sarah Pohjola, Senior Art Exhibition Portfolio, Earth's Destruction, Sarah Pohjola

Senior Art Portfolios

This work was created for the Senior Art Exhibition Portfolio 2024. This work includes graphic design and illustration focused on environmental conservation.

Soil Organic Matter Diagenetic State Informs Boreal Forest Ecosystem Feedbacks To Climate Change, Allison N. Myers-Pigg, Karl Kaiser, Ronald Benner, Susan E. Ziegler

Faculty Publications

The fate of soil organic carbon (SOC) in boreal forests is dependent on the integrative ecosystem response to climate change. For example, boreal forest productivity is often nitrogen (N) limited, and climate warming can enhance N cycling and primary productivity. However, the net effect of this feedback on the SOC reservoir and its longevity with climate change remain unclear due to difficulty in detecting small differences between large and variable carbon (C) fluxes needed to determine net changes in soil reservoirs. The diagenetic state of SOC – resulting from the physicochemical and biological transformations that alter the original biomolecular composition …

Analysis Of Fossil Pollen From A Pleistocene Cypress Forest Preserved On The Northern Gulf Of Mexico Continental Shelf, Kathryn Joyce Garretson

Master's Theses

This study presents the findings of fossil pollen analysis performed on terrestrial sediments preserved on the northern Gulf of Mexico continental shelf (site hereafter known as the Underwater Forest or DF). This research aims to establish vegetation composition on a continental shelf glacial refuge and provide a better understanding of vegetation response to sea-level rise. Two cores (15DF1 and 15DF3B) located at different locations within the forest were recovered and analyzed. Pollen results from both cores were similar, with high percentages of Taxodium and Nyssa pollen in the lowermost sections reflecting an assemblage typical of contemporary baldcypress swamps. Pollen assemblages …

Biochemical And Structural Controls On The Decomposition Dynamics Of Boreal Upland Forest Moss Tissues, Michael Philben, Sara Butler, Sharon A. Billings, Ronald Benner, Kate A. Edwards, Susan E. Ziegler

Faculty Publications

Mosses contribute an average of 20 % of boreal upland forest net primary productivity and are frequently observed to degrade slowly compared to vascular plants. If this is caused primarily by the chemical complexity of their tissues, moss decomposition could exhibit high temperature sensitivity (measured as Q10) due to high activation energy, which would imply that soil organic carbon (SOC) stocks derived from moss remains are especially vulnerable to decomposition with warming. Alternatively, the physical structure of the moss cell-wall biochemical matrix could inhibit decomposition, resulting in low decay rates and low temperature sensitivity. We tested these hypotheses by …

Exploring The Relationship Between Climate And Forest Conditions In Forest Classee De La Mondah (Gabon) Using Remote Sensing Data, Mariano Mboumba

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

This study aims to examine the relationship between temperature and precipitation as climatic factors and the vegetation characteristics in Forêt Classée de la Mondah (Gabon). A pixel based spatial analysis procedure with QGIS was used to extract vegetation characteristics from MODIS on Terra, NDVI band, data from February 2000 to December 2015, while temperature and precipitation were monitored from January 1980 to December 2015 to highlight climate fluctuations in the study area. Two regression analyses were conducted : one between temperature and NDVI and the other one between precipitation and NDVI. Results showed that temperature and precipitation did not vary …

Slides: Murray-Darling Basin, Australia, Tony Mcleod

Coping with Water Scarcity in River Basins Worldwide: Lessons Learned from Shared Experiences (Martz Summer Conference, June 9-10)

Presenter: Tony McLeod, MDBA, Murray-Darling Basin Authority

17 slides

Negative Feedbacks On Bark Beetle Outbreaks: Widespread And Severe Spruce Beetle Infestation Restricts Subsequent Infestation, Sarah J. Hart, Thomas T. Veblen, Nathan Mietkiewicz, Dominik Kulakowski

Geography

Understanding disturbance interactions and their ecological consequences remains a major challenge for research on the response of forests to a changing climate. When, where, and how one disturbance may alter the severity, extent, or occurrence probability of a subsequent disturbance is encapsulated by the concept of linked disturbances. Here, we evaluated 1) how climate and forest habitat variables, including disturbance history, interact to drive 2000s spruce beetle (Dendroctonus rufipennis) infestation of Engelmann spruce (Picea engelmannii) across the Southern Rocky Mountains; and 2) how previous spruce beetle infestation affects subsequent infestation across the Flat Tops Wilderness in northwestern Colorado, which experienced …

Modeling The Effects Of The Hemlock Woolly Adelgid On Carbon Storage In Northern New England Forests, Jeffrey John Krebs

Graduate College Dissertations and Theses

The hemlock woolly adelgid (HWA, Adelges tsugae Annand) is an invasive insect that threatens to eradicate native eastern hemlock (Tsuga canadensis (L.) Carr.) across the eastern United States. In southern New England and southern Appalachian forests, HWA-induced hemlock mortality has impacted carbon (C) flux by altering stand age, litter composition, species composition, and coarse woody debris levels. However, no one has examined how total C storage and sequestration may be impacted by these changes. Further, while projections are that HWA will ultimately infest hemlock across its entire geographic range, the majority of studies have been limited to southern New …

Slides: Forests And Grasslands, Federico Cheever

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

Presenter: Professor Federico Cheever, University of Denver Sturm College of Law

30 slides