2015 CGRER Seed Grants - $148,191

Early hominins and Pleistocene climate in Southern Wallacea:  Russell L. Ciochon, Department of Anthropology, The University of Iowa

With Pleistocene climate cycling, Island Southeast Asia became an expanse of ecologically dynamic landmasses. A million and a half years ago, Homo erectus arrived to the western landmasses and, by a million years ago, pushed onto the smaller islands east of Wallace’s Line. The unique Flores island find of Homo floresiensis evinces one evolutionary result. On Flores and other core Wallacea islands, Stegodon (extinct Asian elephant) and Paleolithic stone tools co-occur archaeologically. Common habitat variables are indicated for both forms. Farther south, on the Southern Wallacea outer arc (Sumba and Timor islands), stone tools and stegodontid fossils are also present, but temporal cooccurrenceis not as clear. Toward understanding early hominin outer arc habitats, this project will evaluate stratigraphy and geochemistry at eight sites with stegodontid fossils and/or stone tools. One or two sequences will be sampled intensively for radiometric age and isotopic climatic indicators.  $30,000

Fate Studies of Insensitive Munitions Explosives in Poplar and Methlyobacteria:  Dr. Craig L. Just, Department of Civil & Environmental Engineering, The University of Iowa

The environmental fate of 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazole-5-one (NTO), and 1-nitroguanidine (NQ) in new insensitive munitions explosives (IMX) formulations is an emerging global issue. The new IMX formulations are replacing old formulations at a rapid pace, but IMX has a relatively unknown fate and ecosystem toxicity. The proposed research will examine IMX fate in poplar trees, poplar tissue cultures, and poplar endophytic bacteria. The research will focus on uptake and partitioning by whole trees and degradation of IMX by poplar tissue cultures and poplar-associated bacteria in vitro. The results will inform the possibility of in situ remediation by poplar trees toward field-scale implementations. Full-scale remediation will be necessary for military training and testing sites around the world, and this research will confirm the viability of the energy-efficient and economical technique of tertiary treatment by poplar trees, as opposed to costly techniques such as incineration or landfilling of contaminated soils.  $29,896

Seeing the urban forest for the trees: An assessment of the relationships between urban forests and biodiversity, carbon storage, and carbon sequestration:  Dr. Heather Sander, Assistant Professor, Department of Geographical and Sustainability Sciences, The University of Iowa

Over half of today’s population is urban, a number expected to rise to nearly three-quarters by mid-century. Cities occupy little land, but have large ecological footprints, influencing environmental quality within and beyond their boundaries. Urbanization will thus dramatically alter ecosystems, making it critical to manage cities to enhance ecosystem services. Urban forests execute many ecological functions, making them key in such management. However, current poor understanding of these functions limits such urban forest management. The proposed research, which aims to identify how urban forests influence spatial variability in urban biodiversity and carbon storage and sequestration and the regional generalizability of these relationships, seeks to fill this gap by quantifying relationships between urban forests and ecosystem services in cities in the US Corn Belt. This study will increase our understanding of how urban forests influence biodiversity and ecosystem services, facilitating management to both support species conservation and enhance urban sustainability.  $28,899

Effects of larval nutritional stress on honey bee disease susceptibility and immunocompetence:  Amy L. Toth,  Adam G. Dolezal, Department of Ecology, Evolution and Organismal Biology, Iowa State University; Department of Entomology, Iowa State University

Honey bees and other pollinators are important to natural ecosystems and sustainable agriculture, but recent bee declines have been alarming. Increased disease exposure and poor nutrition due to decreasing plant diversity have been implicated as likely contributors to pollinator declines. These factors also appear to interact, as recent evidence shows that a low-diversity pollen diet increases disease susceptibility in adult honey bees. However, previous re-search has overlooked the importance of nutrition during the sensitive period of larval de-velopment. Nutritional stress on immatures can potentially have life-long and dire conse-quences on the health of adult workers, queens, and entire colonies. To date, it is unclear how nutritional deprivation during development affects disease resistance and immunocompe-tence at later stages. To address this, we will treat developing honey bees using two forms of field-relevant nutritional stress and test pathogen susceptibility and immune function in these bees as pupae and adults. The results of this work will help us better understand how the effects of poor nutrition during development is translated into health effects later in life, and will pave the way for more in-depth investigations of honey bee health and immunity.  $30,000

Modeling Nonstationary Spatio-temporal Data on Stream Networks:  Dale L. Zimmerman, Robert V. Hogg Professor of Statistics, Department of Statistics and Actuarial Sciences, The University of Iowa

Statistical methods for spatio-temporal prediction and temporal trend estimation have long been available for environmental variables on Euclidean domains, but are not yet available for variables on stream networks. The proposed research will develop new models for nonstationary and spatio-temporal processes on stream networks. It will also modify or extend the Torgegram — a graphical tool for characterizing spatial dependence on stream networks — for use with nonstationary spatio-temporal data. The performance of new hypothesis tests for stationarity and space-time separability based on these new Torgegrams will be investigated. The combined effect of these efforts will be to make statistically sound spatiotemporal prediction and trend estimation possible on stream networks.  $30,000