Physical Sciences and Mathematics Commons^™

Low-Emission Beef Production In The Southern Rangelands Of Western Australia: An Analysis Of Herd Structure And Stocking Rate Experiencing Droughts, Christophe D'Abbadie

Animal Production and Livestock Research Articles

Reconciling profitable cattle production with rangeland health and reduced emissions is a key challenge in the southern rangelands of Western Australia (WA). Stocking rate and herd structure selection are crucial decisions to achieve this balance. This study assessed the emission profiles of three contrasting herd structures (weaner production, live export, and slaughter production), and three stocking rates within a herd–carbon accounting modelling framework. The analysis considers the impact of varying drought frequencies on these cattle production systems. Herd models were developed for the semiarid southern WA rangelands. Stocking rates were set at 100%, 80% and 66% of the government recommended …

Spatiotemporal Plasticity In Reproductive Readiness And Recruitment Of Ichthyoplankton Of Invasive Silver Carp Along A Western Invasion Front, Jessi L. Urichich

School of Natural Resources: Dissertations, Theses, and Student Research

Individuals of invasive species at the edge of their invasion distribution may exhibit enhanced reproductive capacity and phenotypic plasticity leading to accelerated range expansion. Environmental conditions in highly fluctuating environments at distribution edges may either promote or hinder such reproductive readiness and phenotypic plasticity. Dynamic habitat conditions and periodic disturbances experienced in prairie streams, such as drought (e.g., low-flow, high water temperatures), may potentially reduce suitable spawning environments and ichthyoplankton recruitment of invasive Silver Carp, potentially slowing range expansion or enabling management strategies that reduce abundance in the absence of a reproducing population. Female Silver Carp batch fecundity, Gonadosomatic Index …

Heavy Steers And Heifers Run At Low Stocking Rates Enhance Drought Resilience In A Pastoral Region Of Australia, Christophe D'Abbadie, Ross Kingwell, Philip E. Vercoe, Bradley Plunkett, Alan Peggs

Animal Production and Livestock Research Articles

CONTEXT

The semi-arid mulga lands of the Southern Rangelands of Western Australia experience frequent droughts. Maintaining a profitable animal grazing enterprise whilst preserving rangeland condition requires selecting an appropriate stocking rate and herd structure.

OBJECTIVE

We construct and apply bioeconomic models of beef enterprises for the semi-arid Southern Rangelands of Western Australia, to assess the profitability and relative riskiness of three different livestock production systems and three different stocking rates when exposed to different frequencies of drought.

METHODS

We construct bio-economic models of herd structures that separately focus on producing either: (i) 200 kg heifers and 210 kg steers (ii) …

Drought Legacy Interacts With Wildfire To Alter Soil Microbial Communities In A Mediterranean Climate-Type Forest, Anna J. M. Hopkins, Aaron J. Brace, Jess L. Bruce, J. Hyde, J. B. Fontaine, L. Walden, W. Veber, K. X. Ruthrof

Research outputs 2022 to 2026

Mediterranean forest ecosystems will be increasingly affected by hotter drought and more frequent and severe wildfire events in the future. However, little is known about the longer-term responses of these forests to multiple disturbances and the forests' capacity to maintain ecosystem function. This is particularly so for below-ground organisms, which have received less attention than those above-ground, despite their essential contributions to forest function. We investigated rhizosphere microbial communities in a resprouting Eucalyptus marginata forest, southwestern Australia, that had experienced a severe wildfire four years previously, and a hotter drought eight years previously. Our aim was to understand how microbial …

Updating The Dual C And O Isotope—Gas-Exchange Model: A Concept To Understand Plant Responses To The Environment And Its Implications For Tree Rings, Rolf T. W. Siegwolf, Marco M. Lehmann, Gregory R. Goldsmith, Olga V. Churakova (Sidorova), Cathleen Mirande-Ney, Galina Timoveeva, Rosmarie B. Weigt, Matthias Saurer

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The combined study of carbon (C) and oxygen (O) isotopes in plant organic matter has emerged as a powerful tool for understanding plant functional responses to environmental change. The approach relies on established relationships between leaf gas exchange and isotopic fractionation to derive a series of model scenarios that can be used to infer changes in photosynthetic assimilation and stomatal conductance driven by changes in environmental parameters (CO₂, water availability, air humidity, temperature, nutrients). We review the mechanistic basis for a conceptual model, in light of recently published research, and discuss where isotopic observations do not match our …

Physiological And Transcriptomic Responses Of Two Artemisia Californica Populations To Drought: Implications For Restoring Drought-Resilient Native Communities, Hagop S. Atamian Dr., Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As climate change brings drier and more variable rainfall patterns to many arid and semi-arid regions, land managers must re-assemble appropriate plant communities for these conditions. Transcriptome sequencing can elucidate the molecular mechanisms underlying plant responses to changing environmental conditions, potentially enhancing our ability to screen suitable genotypes and species for restoration. We examined physiological and morphological traits and transcriptome sequences of coastal and inland populations of California sagebrush (Artemisia californica), a critical shrub used to restore coastal sage scrub vegetation communities, grown under low and high rainfall environments. The populations are located approximately 36 km apart but …

Timing And Magnitude Of Drought Impacts On Carbon Uptake Across A Grassland Biome, Andrew Felton, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Although drought is known to negatively impact grassland functioning, the timing and magnitude of these impacts within a growing season remains unresolved. Previous small-scale assessments indicate grasslands may only respond to drought during narrow periods within a year; however, large-scale assessments are now needed to uncover the general patterns and determinants of this timing. We combined remote sensing datasets of gross primary productivity and weather to assess the timing and magnitude of grassland responses to drought at 5 km² temporal resolution across two expansive ecoregions of the western US Great Plains biome: the C₄-dominated shortgrass steppe and …

Evolution Of The Southwest Drought Learning Network: Collective Response To Exceptional Drought, E. Elias, B. Fuchs, J. Lisonbee, T. Bernadt, V. Martinez, T. Haigh

School of Natural Resources: Documents and Reviews

No abstract provided.

Drought Levels In Nevada Counties, 2022, Julianna Jovillar, Caitlin J. Saladino, William E. Brown Jr.

Environment

This fact sheet synthesizes data on drought levels within Nevada counties from the National Integrated Drought Information System (NIDIS) in 2022. The information presented in this document focuses on the breakdown of the number of Nevada residents affected by the droughts within each county and the drought experience in each county.

Precipitation Is A Strong Predictor Of Airborne Ammonia Levels., Bridger Jorgensen, Casey Olson, Connor Snow

Research on Capitol Hill

USU senior Connor has lived in the Uintah Basin all his life and studies kinesiology. Senior Casey, a Cache Valley native, studies climate science and works at the Utah Climate Center. Junior Bridger, also of Cache Valley, studies nutrition science. They led and funded this project through a student grant. Casey was alarmed by the ammonia data he was collecting at the Climate Center. “I immediately began to wonder how this issue would evolve over the coming decades.” The three teamed up to take a look at how Logan’s record-breaking amount of ammonia in our air is impacting those who …

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …

Tile Drainage Flow Partitioning And Phosphorus Export In Vermont Usa, Ryan Ruggiero, Donald Ross, Joshua W. Faulkner

Lake Champlain Sea Grant Institute

Tile drainage (TD) has been identified as a potential non-point source of phosphorus (P) pollution and subsequent water quality issues. Three fields with TD in Vermont USA were monitored to characterize hydrology and P export. Fields were in corn silage and used minimal tillage and cover cropping practices. Preferential flow path (PFP) activity was explored by separating TD flow into flow pathway and source connectivity components using two hydrograph separation techniques, electrical conductivity end member unmixing, and hydrograph recession analysis. TD was the dominant P export pathway because of higher total discharge. Drought conditions during this study limited surface runoff, …

Evidence For Irruptive Fluctuation In Axis Deer Of Hawai‘I, Steven C. Hess, Jonathan Sprague, Jacob Muise

United States Department of Agriculture Wildlife Services: Staff Publications

Axis deer on the Hawaiian Islands of Maui, Lāna‘i, and Moloka‘i simultaneously experienced one of the most dramatic population crashes on record in 2020-2021, which coincided with extended drought conditions and prompted an emergency declaration for these islands. This phenomenon has been anecdotally documented during previous drought events in 2011-2012, but never formally studied. Newspaper articles document abundant deer becoming a nuisance to agriculture and natural resources, and then experiencing high mortality during droughts. This phenomenon fits Caughley’s (1970) operational definition of eruptive (sic) fluctuation “…as an increase in numbers over at least two generations, followed by a marked decline.” …

Assessing And Mapping The Spatial-Temporal Change In Forest Phenology Of Arabuko-Sokoke Forest Using Moderate Resolution Satellite, Bailey Ytterdahl

Independent Study Project (ISP) Collection

This study focuses on coastal forests in Kenya that have some of the highest variety of flora and fauna, specifically Arabuko Sokoke Forest. Arabuko Sokoke Forest is located 110 miles north of Mombasa and 18 kilometers south of Malindi. This forest is known to be a worldwide biodiversity hotspot that is home to endemic and rare plants and animals. Within the Arabuko Sokoke Forest ecosystem, there are two main issues that challenge the conservation of the area. First, there has been more competition for land, primarily for agriculture and development. Second, there is an increase demand for forest resources due …

A Record Of Vapour Pressure Deficit Preserved In Wood And Soil Across Biomes, Adrian Broz, Gregory J. Retallack, Toby M. Maxwell, Lucas C.R. Silva

Biology Faculty Publications and Presentations

The drying power of air, or vapour pressure deficit (VPD), is an important measurement of potential plant stress and productivity. Estimates of VPD values of the past are integral for understanding the link between rising modern atmospheric carbon dioxide (pCO₂) and global water balance. A geological record of VPD is needed for paleoclimate studies of past greenhouse spikes which attempt to constrain future climate, but at present there are few quantitative atmospheric moisture proxies that can be applied to fossil material. Here we show that VPD leaves a permanent record in the slope (S) of least-squares …

Drought In The Breadbasket Of America And The Influence Of Oceanic Teleconnections, Grace Campbell

Mahurin Honors College Capstone Experience/Thesis Projects

From 1980 to 2020, drought events accounted for 11.4% of the billion-dollar disasters in the United States (U.S.) yet caused the second highest total amount in damages at $236.6 billion. With the average cost of a drought being upwards of $9.5 billion, these natural disasters can create serious problems in agriculture. Drought is defined as a period of below average precipitation that causes damage to agriculture and water supply. Previous research has linked drought events in the U.S. Great Plains to oceanic teleconnections in the Pacific and Atlantic basins, indicating the influence of the El Niño – Southern Oscillation (ENSO), …

Influence Of Forest-To-Silvopasture Conversion And Drought On Components Of Evapotranspiration, Adam P. Coble, Alexandra R. Contosta, Richard G. Smith, Nathan W. Siegert, Matthew A. Vadeboncoeur, Katie A. Jennings, Anthony J. Stewart, Heidi Asbjornsen

Natural Resources & the Environment

The northeastern U.S. is projected to experience more frequent short-term (1-2 month) droughts interspersed among larger precipitation events. Agroforestry practices such as silvopasture may mitigate these impacts of climate change while maintaining economic benefits of both agricultural and forestry practices. This study evaluated the effects of forest-to-silvopasture (i.e., 50% thinning) conversion on the components of evapotranspiration (transpiration, rainfall interception, and soil evaporation) during the growing season of 2016. The study coincided with a late-summer drought throughout the northeastern U.S., which allowed us to also evaluate the effects of forest-to-silvopasture conversion on drought responses of multiple tree species, including Pinus strobus, …

Assessing Agricultural Risk Management Using Historic Crop Insurance Loss Data Over The Ogallala Aquifer, Julian Reyes, Emile Elias, Erin M.K. Haacker, Amy Kremen, Lauren Parker, Caitlin Rottler

Department of Earth and Atmospheric Sciences: Faculty Publications

Much of the agricultural production in the Ogallala Aquifer region relies on groundwater for irrigation. In addition to declining water levels, weather and climate-driven events affect crop yields and revenues. Crop insurance serves as a risk management tool to mitigate these perils. Here, we seek to understand what long-term crop insurance loss data can tell us about agricultural risk management in the Ogallala. We assess patterns and trends in crop insurance loss data from the U.S. Department of Agriculture Risk Management Agency. Indemnities, or insurance payments, totaled $22 billion from 1989–2017 for the 161 counties that overlie the Ogallala Aquifer. …

Quantifying The Impact Of Climate Change And Human Activities On Streamflow In A Semi-Arid Watershed With The Budyko Equation Incorporating Dynamic Vegetation Information, Lei Tian, Jiming Jin, Pute Wu, Guo-Yue Niu

Watershed Sciences Faculty Publications

Understanding hydrological responses to climate change and land use and land cover change (LULCC) is important for water resource planning and management, especially for water-limited areas. The annual streamflow of the Wuding River Watershed (WRW), the largest sediment source of the Yellow River in China, has decreased significantly over the past 50 years at a rate of 5.2 mm/decade. Using the Budyko equation, this study investigated this decrease with the contributions from climate change and LULCC caused by human activities, which have intensified since 1999 due to China’s Grain for Green Project (GFGP). The Budyko parameter that represents watershed characteristics …

Does Drought Affect Reproduction In The Saltmarsh Sparrow (Ammodramus Caudacutus)?, Valerie K. Watson

Honors College

The Saltmarsh Sparrow (Ammodramus caudacutus) is experiencing steep population declines, with extinction likely within the next few decades. Sea-level rise has been identified as a major threat to the species, but little has been done to examine the effects of other aspects of climate change on Saltmarsh Sparrow populations. In this study, I examine whether drought affects reproductive success in the Saltmarsh Sparrow. I use nest- and chick-monitoring data collected over five years across the northern half of the species range to test whether drought conditions affect four metrics of reproductive success in these birds: hatch rate, clutch …

Severe Drought Impacts Female Pheasant Physiology In Southwest Nebraska, Jessica A. Laskowski, Gwen C. Bachman, Joseph J. Fontaine

The Prairie Naturalist

In 2012, Nebraska experienced one of the worst droughts since the 1930s, accompanied by abnormally high temperatures. We studied the impacts of the 2012 summer drought on female ring-necked pheasant (Phasianus colchicus) body condition and baseline and stress-induced corticosterone concentrations (CORT). We hypothesized that drought conditions would reduce pheasant body condition, increase chronic stress resulting in elevated baseline CORT levels, and down-regulate pheasant stress response to acute stressors, resulting in reduced stress-induced CORT concentrations. In southwestern Nebraska, we captured female pheasants in 2012 (pre-drought) and 2013 (post-drought). Pheasants had poorer body condition after the drought. Although female CORT measures were …

Capturing Species-Level Drought Responses In A Temperate Deciduous Forest Using Ratios Of Photochemical Reflectance Indices Between Sunlit And Shaded Canopies, Taehee Hwang, Hamed Gholizadeh, Daniel A. Sims, Kimberly A. Novick, Edward R. Brzostek, Richard P. Phillips, Daniel T. Roman, Scott M. Robeson, Abdullah F. Rahman

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Highlights

• We examine capability of spectral indices to capture isohydric/anisohydric behavior.

• We used both in-situ spectral measurements and multi-angle MODIS images.

• Only PRI could capture species-level drought responses.

• This study presents a step forward to directly mapping emergent isohydricity.

Abstract

To classify trees along a spectrum of isohydric to anisohydric behavior is a promising new framework for identifying tree species' sensitivities to drought stress, directly related to the vulnerability of carbon uptake of terrestrial ecosystems with increased hydroclimate variability. Trees with isohydric strategies regulate stomatal conductance to maintain stationary leaf water potential, while trees with anisohydric strategies allow leaf …

Do Advisors Perceive Climate Change As An Agricultural Risk? An In-Depth Examination Of Midwestern U.S. Ag Advisors’ Views On Drought, Climate Change, And Risk Management, Sarah P. Church, Michael Dunn, Nicholas Babin, Amber Saylor Mase, Tonya Haigh, Linda Stalker Prokopy

Drought Mitigation Center: Faculty Publications

Through the lens of the Health Belief Model and Protection Motivation Theory, we analyzed interviews of 36 agricultural advisors in Indiana and Nebraska to understand their appraisals of climate change risk, related decision making processes and subsequent risk management advice to producers. Most advisors interviewed accept that weather events are a risk for US Midwestern agriculture; however, they are more concerned about tangible threats such as crop prices. There is not much concern about climate change among agricultural advisors. Management practices that could help producers adapt to climate change were more likely to be recommended by conservation and Extension advisors, …

Severe Drought Impacts Female Pheasant Physiology In Southwest Nebraska, Jessica A. Laskowski, Gwendolyn C. Bachman, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

In 2012, Nebraska experienced one of the worst droughts since the 1930s, accompanied by abnormally high temperatures. We studied the impacts of the 2012 summer drought on female ring-necked pheasant (Phasianus colchicus) body condition and baseline and stress-induced corticosterone concentrations (CORT). We hypothesized that drought conditions would reduce pheasant body condition, increase chronic stress resulting in elevated baseline CORT levels, and down-regulate pheasant stress response to acute stressors, resulting in reduced stress-induced CORT concentrations. In southwestern Nebraska, we captured female pheasants in 2012 (pre-drought) and 2013 (post-drought). Pheasants had poorer body condition after the drought. Although female CORT …

Agenda: Coping With Water Scarcity In River Basins Worldwide: Lessons Learned From Shared Experiences, University Of Colorado Boulder. Getches-Wilkinson Center For Natural Resources, Energy, And The Environment

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

Water scarcity is increasingly dominating headlines throughout the world. In the southwestern USA, the looming water shortages on the Colorado River system and the unprecedented drought in California are garnering the greatest attention. Similar stories of scarcity and crisis can be found across the globe, suggesting an opportunity for sharing lessons and innovations. For example, the Colorado River and Australia's Murray-Darling Basin likely can share many lessons, as both systems were over-allocated, feature multiple jurisdictions, face similar climatic risks and drought stresses, and struggle to balance human demands with environmental needs. In this conference we cast our net broadly, exploring …

Slides: Food For Thought: Water Requirements For Social-Ecological Systems, Michael Douglas, Sue Jackson

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

Presenters:

Michael Douglas, University of Western Australia, Charles Darwin University

Sue Jackson, Griffith University

35 slides

Slides: The Columbia River Basin, Barbara Cosens

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

Presenter: Barbara Cosens, Professor and Associate Dean of Faculty, University of Idaho College of Law, Waters of the West Interdisciplinary Program

16 slides

Drought Risk Management For Beef Cattle Farms, Stephen F. Higgins, Lee Moser, Kylie Schmidt

Agriculture and Natural Resources Publications

One of the most challenging aspects of owning and operating any farming operation is dealing with uncertainty. Uncertainty on the farm comes in many forms; livestock health, feed prices, fuel prices, market prices, and weather to name a few. Over the past decade, the prevalence and impact of drought on agriculture has dramatically increased, thus adding further uncertainty to farmers’ decision-making processes. Drought and the associated loss of productivity is a real risk scenario that all farmers must face. With this inherent risk, one must protect their farm and the environment it impacts through a sound decision-making process that factors …

Experimental Evidence For Drought Induced Alternative Stable States Of Soil Moisture, David A. Robinson, Scott B. Jones, Inma Lebron, Sabine Reinsch, Maria T. Dominguez, Andrew R. Smith, Davey L. Jones, Miles R. Marshall, Bridget A. Emmett

Plants, Soils, and Climate Faculty Publications

Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought, and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ∼10%. However, intense summer drought, …

Riparian Vegetation, Colorado River, And Climate: Five Decades Of Spatiotemporal Dynamics In The Grand Canyon With River Regulation, Joel B. Sankey, Barbara Ralston, Paul E. Grams, John C. Schmidt, Laura E. Cagney

Watershed Sciences Faculty Publications

Documentation of the interacting effects of river regulation and climate on riparian vegetation has typically been limited to small segments of rivers or focused on individual plant species. We examine spatiotemporal variability in riparian vegetation for the Colorado River in Grand Canyon relative to river regulation and climate, over the five decades since completion of the upstream Glen Canyon Dam in 1963. Long-term changes along this highly modified, large segment of the river provide insights for management of similar riparian ecosystems around the world. We analyze vegetation extent based on maps and imagery from eight dates between 1965 and 2009, …