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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Evolutionary Responses Of Invasive Grass Species To Variation In Precipitation And Soil Nitrogen, Monica A. Nguyen, Amy E. Ortega, Quoc L. Nguyen, Sarah Kimball, Michael L. Goulden, Jennifer L. Funk Apr 2016

Evolutionary Responses Of Invasive Grass Species To Variation In Precipitation And Soil Nitrogen, Monica A. Nguyen, Amy E. Ortega, Quoc L. Nguyen, Sarah Kimball, Michael L. Goulden, Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

1.Global climate models suggest that many ecosystems will experience reduced precipitation over the next century and the consequences for invasive plant performance are largely unknown. Annual invasive species may be able to quickly evolve traits associated with drought escape or tolerance through rapid genetic changes.

2.We investigated the influence of five years of water and nitrogen manipulations on trait values in a southern California grassland system. Seeds from two annual grass species (Avena barbata, Bromus madritensis) were collected from experimental plots and grown in a common environment over two generations. We measured 14 physiological, morphological, phenological, and …


Spatiotemporal Variability Of Plant Phenology In Drylands: A Case Study From The Northern Chihuahuan Desert, Naomi Robin Luna Jan 2016

Spatiotemporal Variability Of Plant Phenology In Drylands: A Case Study From The Northern Chihuahuan Desert, Naomi Robin Luna

Open Access Theses & Dissertations

With global change, which includes climate change, there is a sense of urgency to understand how shifts in climate will affect ecosystems. Although several studies have improved understanding of how and why some ecosystems respond, most studies have not explored simultaneous responses of different land cover types throughout a given region. Dryland ecosystems, such as the Chihuahuan Desert, appear to respond to climate variability and currently make up about 40% of global land surface area. It is expected that drylands will expand to cover 60% of land surface area on earth by mid-century making this ecosystem more critical to global …


An Agent-Based Modeling Approach To Determine Winter Survival Rates Of American Robins And Eastern Bluebirds, Samuel Iselin, Shannon Segin, Alex Capaldi Dec 2015

An Agent-Based Modeling Approach To Determine Winter Survival Rates Of American Robins And Eastern Bluebirds, Samuel Iselin, Shannon Segin, Alex Capaldi

Alex Capaldi

American Robins (Turdus migratorius) and Eastern Bluebirds (Sialia sialis) are two species of migratory thrushes that breed in Northwest Indiana but historically are uncommon during the winter season. These trends have changed recently, and both species are seen more abundantly during the winter. Recently invaded non-native fruiting plants continue to provide nutrients for the birds throughout the winter and may contribute to the increased avian populations during that time. To measure the effect these food sources contribute to thrush wintering habits, we created an agent-based computer model to simulate the birds' movement in Northwest Indiana along …