Assessing Stream Ecosystem Structure and Function in an Urban Canal and Logan River in Logan, Utah

Humans have constructed canals to support agriculture, to mitigate flooding, and to discharge stormwater, especially in the Intermountain West. These canals are common in Cache Valley, where they receive flows from the Logan River during summer months. However, the ecological structure (e.g., water quality, freshwater invertebrates) and function (e.g., leaf decomposition) of these canals remains largely unknown. Studying ecosystem structure and function of these urban waterways is important because it can inform us of the health of these waterways. My research had three objectives. First, I compared water chemistry, invertebrate assemblages, and leaf decomposition in an urban canal and the Logan River in Logan, Utah. Next, I compared these variables along a longitudinal urban gradient (i.e., from upstream reaches to downstream reaches of the waterways). Last, I examined which of the various environmental factors I measured was correlated with shredders (i.e., leafshredding invertebrates) and leaf decomposition in both waterways. Water quality was similar between the Logan River and the canal, except for the most downstream site of the Logan River which had a higher concentration of nutrients and heavy metals. The canal had faster leaf decomposition, and facultative shredders were abundant in the canal. Facultative shredders increased with the decay rate in the canal, suggesting that these shredders are playing a critical role aiding in leaf decomposition in the canal. The most downstream sites in the canal may have had faster leaf decomposition due to facultative shredders whereas the most downstream sites in the Logan River may have had faster decomposition because of elevated concentrations of nutrients. I found that physical forces from the flow of streams (e.g., water velocity) and shredder biomass were correlated with leaf decomposition in both waterways. Total phosphorus was also correlated with shredder biomass and leaf decomposition, the latter of which is likely due to enhanced microbial activity on leaf litter

ASSESSING THE EFFECTS OF SOIL MOISTURE ON GERMINATION OF WINTER WHEAT

Drought is a major issue in wheat production globally and in Nebraska particularly during germination. Rapid germination is important for satisfactory stands whereas late germination may lead to a lower yield. Laboratory experiments were conducted at the University of Nebraska-Lincoln (UNL) to compare germination of five Nebraska-grown wheat varieties, or cultivars, under water stress conditions. The cultivars, Anton, Nuplains, Pronghorn, Trego, and Wesley were selected because of their presumed differing water use efficiency (WUE). Tests were conducted on a Nebraska soil to create a soil water release curve and to select soil moisture level or water treatments. The experimental design was a 3X5 factorial consisting of three water treatments and 5 cultivars replicated four times. Seeds with the appropriate water treatments were incubated at 21o C and germination success was measured on the fifth and twelfth day after incubation. Analysis of variance was used for data analyses and significance tests. Germination differed significantly across cultivars and water treatments. A significant interaction was found between cultivars and water treatment (

Assessing Ecosystem Structure and Function in the Logan River and an Urban Canal in Logan, UT

Urban water systems are highly managed, especially in the semi-arid, Intermountain West. Here, humans have constructed extensive conveyance systems to support agriculture, mitigate flooding, and discharge stormwater. Despite their regional prevalence, the ecological structure and functioning of these conveyance systems remains largely unknown. To address this gap, we are comparing ecosystem structure and function (i.e. leaf decomposition) between an urban canal the Logan River in Logan, Utah. We hypothesized that leaf decomposition would be slower in the canal compared to the river because of reduced shredder biomass associated with poorer water quality. We also expected water temperature and concentrations of nutrients and metals to be higher at sites further downstream in both waterways, due to the accumulation of stressors as they flow through urban areas. To test these hypotheses, we collected water quality and freshwater invertebrates samples and measured leaf decomposition at twenty sites along the Logan River and an urban canal. Our results did not support these hypotheses. The canal showed faster leaf decomposition as the canal had a significantly lower amount of ash-free dry mass remaining in coarse-mesh litter bags compared to the river. Leaf breakdown was driven by a significantly higher biomass of shredders (Hyalella sp.) in the canal compared to the Logan River. Water chemistry data of several nutrients and metals suggest that the lower reaches of the Logan River have poorer water quality than both the canal and the upstream reaches of the river. Our results suggest that man-made waterways can retain important ecological services

Worldviews more than experience predict Californians’ support for wildfire risk mitigation policies

California must adapt to increasing wildfire activity concurrent with climate change and expanding housing development in fire-prone areas. Recent decades have seen record-breaking fire activity, economic costs, and human health impacts. Residents more frequently face home evacuations, prolonged periods of unhealthy air quality, and power shut-offs. Understanding how these experiences influence support for risk mitigation policies is essential to inform action on climate and fire adaptation. To better understand linkages between experience and policy support, we surveyed California residents ( n = 645) about their wildfire-related experiences, risk perceptions, and support for 18 wildfire risk mitigation policies. To assess how the relationship between policy support and wildfire experience is modulated by preexisting worldviews, we measured the extent to which respondents are motivated by individualistic or communitarian values as proposed in the cultural theory of risk. We surveyed residents across a gradient of wildfire impacts, spatially stratifying residences based on wildland-urban-interface type and proximity to large 2020 wildfires. Support was generally high for most policies, though most respondents opposed incorporating future risk into insurance rates and coverage. Policy support models showed that communitarian worldviews were more consistently associated with greater support for diverse wildfire mitigation policies than were measures of recent experience with wildfire. These results suggest that California residents within our sample regions already support many wildfire risk mitigation strategies, and preexisting societal beliefs are a stronger predictor of these views than personal experiences with wildfire. Policy-makers can utilize this understanding to focus on crafting policies and messaging that resonates with individualistic values