Digital Commons Network^™

An Investigation On Inventory Of Sub-Steppic Meadows In Northwestern Iran, Mansour Mesdaghi

IGC Proceedings (1977-2023)

The meadows of the Ardabill region with an area of 77,000 hectares, make up about 50% of the total areas scattered in central and western parts of Ardabill. The objectives of this research were to identify and classify the meadows based on vegetation. It was observed that among eight representative stands, Vagah-sara and Samian were more diverse compared to the other stands. The richness increases as soil moisture increases. From the standpoint of life form, hemicryptophytes and therophytes dominated. Productions of dry matter were 3900 and 3700 kg/ha at Arjestan and Khatampboulaghi respectively, and were decreased to 1500 kg/ha at …

A Study Of Reasons For The Endangered Status Of Potaninia Mongolica In Arid Desert Grasslands Of China, Wang Jihe, Peng Hongjia, Shi Qian, Zhang Dongming

IGC Proceedings (1977-2023)

Potaninia mongolica is an endangered plant species of arid desert grasslands of China. Reasons for its decline and opportunities for its conservation were investigated by studying the plant’s distribution, biological characteristics, plant community associations and stress resistance.

Modifying Management Methods To Promote The Reform And Development Of Grassland Based Animal Husbandry Through Better Resource Use, Cui Heng-Xin, Zhang Jiang-Ling, Asya Jiang-Ling

IGC Proceedings (1977-2023)

The development of grassland livestock production cannot rely on the cost of pasture degradation. The stocking rate has to be based on the pasture production and it also has to be under the guidance of law. Changing management methods, development of grassland agriculture and optimization of the utilization of natural resources is the effective way of improving the reformation and development of grassland livestock production.

Restoration Of Degraded Coastal Grasslands In The Falkland Island, J A. Kerr

IGC Proceedings (1977-2023)

In the Falkland Islands the coastal grasslands are the most valuable for wool production and important habitats for wildlife. Tussac grass (Parodiochloa flabellata Lam.) and sandy areas which support an Ammophilia - Elymus association have been degraded by overgrazing, burning and invasion by alien flora and fauna. Traditional approaches to restoration, mainly by replanting, have had limited success. Research on

Climate, Food, And Humans Predict Communities Of Mammals In The United States, Roland Kays, Matthew H. Snider, Andrew M. Wilson

Environmental Studies Faculty Publications

The assembly of species into communities and ecoregions is the result of interacting factors that affect plant and animal distribution and abundance at biogeographic scales. Here, we empirically derive ecoregions for mammals to test whether human disturbance has become more important than climate and habitat resources in structuring communities.

Feather Mites Through Genomic And Ecological Lenses: Host Specificity And Symbiosis At Multiple Levels Of Organization, Alix Elizabeth Matthews

Student Theses and Dissertations

Symbionts, or organisms that form close and persistent associations with hosts, are ubiquitous across the tree of life, and symbioses are among the most common interspecific interactions in the natural world. Symbionts play a fundamental ecological and evolutionary role across multiple levels of biological organization – from individuals to ecosystems – and can have strong effects on global biodiversity. However, many aspects of these relationships are poorly understood including symbiont genetic diversity (inter- and intraspecific), host specificity, and the mechanisms underlying their functional nature or any context-dependent patterns. This dissertation uses a model symbiosis between permanent, obligate, ectosymbiotic vane-dwelling feather …

A Harmonized Public Resource Of Deeply Sequenced Diverse Human Genomes, Zan Koenig, Mary T Yohannes, Lethukuthula L Nkambule, Xuefang Zhao, Julia K Goodrich, Heesu Ally Kim, Michael W Wilson, Grace Tiao, Stephanie P Hao, Nareh Sahakian, Katherine R Chao, Mark A Walker, Yunfei Lyu, Heidi L Rehm, Benjamin M Neale, Michael E Talkowski, Mark J Daly, Harrison Brand, Konrad J Karczewski, Elizabeth G Atkinson, Alicia R Martin

Faculty, Staff and Students Publications

Underrepresented populations are often excluded from genomic studies owing in part to a lack of resources supporting their analyses. The 1000 Genomes Project (1kGP) and Human Genome Diversity Project (HGDP), which have recently been sequenced to high coverage, are valuable genomic resources because of the global diversity they capture and their open data sharing policies. Here, we harmonized a high-quality set of 4094 whole genomes from 80 populations in the HGDP and 1kGP with data from the Genome Aggregation Database (gnomAD) and identified over 153 million high-quality SNVs, indels, and SVs. We performed a detailed ancestry analysis of this cohort, …

Winterkill Potential Of Alfalfa Under Different Snow Depths, R H. Leep

IGC Proceedings (1977-2023)

The presence and amount of insulating winter snow cover are key factors in determining the potential of winter injury of alfalfa (Medicago sativa L.) In the Midwestern U.S. Four alfalfa varieties of varying fall dormancy ratings were planted in the summers of 1993 and 1994. Snow depths above the crop plots were kept constant at depths of 0, 10, and 20 cm during the subsequent winters with framed mesh covers. Winterkill percentages during the two seasons varied dramatically from 0-100% and were significantly higher for the 0 cm treatment than for 10 or 20 cm treatments. Nitro, a nondormant …

Effect Of Grazing And Soils On The Structure Of Mountain Vegetation Communities, I Alonso

IGC Proceedings (1977-2023)

The range of life forms of four grassland communities in the Cantabrian mountains (N. Spain) was studied under grazing and when grazing was excluded in relation to soil characteristics. Hemicryptophytes were the most abundant life form in all communities and they increased their number when ungrazed. Diversity was bigger in the communities with shrubs, which presented a more heterogeneous structure. As a whole, grasslands on calcareous soils were more diverse than those on siliceous soils.

Integrating Satellite Images And Species-Based Vegetation Maps To Manage Native Grasslands, M Hall-Beyer, Q.H. J. Gwyn

IGC Proceedings (1977-2023)

Satellite image mapping of grasslands is problematic when species diversity occurs at a sub-pixel scale. We propose a method, called melody classification, to map ground cover units that group several spectral classes (colours). Melodies are defined as the normalized expected frequencies of each class within the ground cover unit. Starting from an unsupervised classification, an image is created showing the probability of finding each spectral class in the vicinity of each pixel. Each pixel is classified by comparing the melody in its neighbourhood with that of each ground cover unit. Accuracies are greatly enhanced over those of supervised classification. Melody …

Perspectives On Modifiable Spatiotemporal Unit Problems In Remote Sensing Of Agriculture: Evaluating Rice Production In Vietnam And Tools For Analysis, Brad G. Peter, Joseph P. Messina, Victoria Breeze, Cadi Y. Fung, Abhinav Kapoor, Peilei Fan

Geosciences Faculty Publications and Presentations

Measuring agricultural productivity is a multiscale spatiotemporal problem that requires multiscale solutions. In Vietnam, rice comprises a substantial portion of the cultivated area and is a major export crop that supplies much of the global food system. Understanding the when and where of rice productivity is vital to addressing changes to yields and food security, yet descriptive summarizations will vary depending on the spatial or temporal scale of analysis. This paper explores rice trends across Vietnam over a 19-year period, giving specific attention to modifiable spatiotemporal unit problems by evaluating productivity across multiple time periods and administrative levels. A generalizable …

Invertebrate Diversity From Deep Wells Of The Southern Boundary Of The Edwards Aquifer Of Southcentral Texas, Kathryn E. Perez, Valentin Cantu, Vanessa Saenz, J. Randy Gibson, Patricia Duncan, Benjamin T. Hutchins

School of Integrative Biological & Chemical Sciences Faculty Publications

This study examined the invertebrate fauna from three deep wells located at the Uvalde National Fish Hatchery in south-central Texas. These wells provide a water source from geological strata of the southern boundary of the Edwards Aquifer ranging in age from Lower Cretaceous to Recent. Forty-seven collections, sampled on a continuous basis from November 2020 to January 2022, produced a total of 738 specimens comprising 15 different species. These collections reveal a diverse crustacean assemblage along with dominant numbers of the stygobiotic snail Balconorbis uvaldensis. This study provides a preliminary survey for future investigations of unidentified crustacean species as …

Uncovering The Dynamic Nature Of Fire Refugia Across Landscapes In Oregon's Western Cascades, Alec Scott Dyer

Dissertations and Theses

With increased fire activity, the presence of fire refugia is critical to support forest resiliency and mitigate large-scale vegetation conversion, however, the persistence of fire refugia within burn perimeters over time is uncertain. This study examines the dynamic nature of fire refugia by mapping the decline in forest cover over time, identifying spatiotemporal patch- and landscape-scale patterns and the biophysical drivers of delayed mortality following the 2020 Labor Day Fires occurring in Oregon’s western Cascades. After three years post-fire, delayed mortality accounted for an additional 8.5% of forest loss (total of 24,147 hectares in all five burns) compared to pre-fire …

Assessing The Climate Resilience Of Quercus Garryana In The Portland Metro Region, Jess Rose Nettle Shamek

Dissertations and Theses

In the context of rapid global climate change, understanding the resilience of local tree species is essential for fostering effective environmental stewardship and community hopefulness. Oregon white oak (Quercus garryana), an emblematic species in the Pacific Northwest, has faced significant habitat loss and degradation since settler colonization. However, it also exhibits a predicted resilience to climate change, potentially leading to a range shift and expansion. Species resilience refers to the capacity of a species to persist and adapt in the face of rapid global climate change. Beyond vulnerability assessments and niche models, we know little about this species' …

The Ecosystem As Super-Organ/Ism, Revisited: Scaling Hydraulics To Forests Under Climate Change, Jeffrey D. Wood, Matteo Detto, Marvin Browne, Nathan J.B. Kraft, Alexandra G. Konings, Joshua B. Fisher, Gregory R. Quetin, Anna T. Trugman, Troy S. Magney, Camila D. Medeiros, Nidhi Vinod, Thomas N. Buckley, Lawren Sack

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Classic debates in community ecology focused on the complexities of considering an ecosystem as a super-organ or organism. New consideration of such perspectives could clarify mechanisms underlying the dynamics of forest carbon dioxide (CO₂) uptake and water vapor loss, important for predicting and managing the future of Earth's ecosystems and climate system. Here, we provide a rubric for considering ecosystem traits as aggregated, systemic, or emergent, i.e., representing the ecosystem as an aggregate of its individuals, or as a metaphorical or literal super-organ or organism. We review recent approaches to scaling-up plant water relations (hydraulics) concepts developed for …

Evidence Of Climatic Influence On Subsistence Strategies At Sage Hen Springs, Nevada, Andrew Rogers

Electronic Theses and Dissertations

Models of settlement patterns in the northwest Great Basin describe a decrease in residential mobility, intensified use of upland spring ecozones, and an increase in diet breadth during the Middle and Late Archaic. Here, I present data collected from the Sage Hen Springs site in northwestern Nevada during a Phase II testing project conducted by the BLM and an analysis of these data focusing on patterns of subsistence and mobility strategies throughout the Archaic. Results of this analysis support existing models of lifeways in the northwest Great Basin at the small scale and point to climatic factors as influences on …

Machine Learning Vegetation Filtering Of Coastal Cliff And Bluff Point Clouds, Phillipe A. Wernette

Michigan Tech Publications

Coastal cliffs erode in response to short- and long-term environmental changes, but predicting these changes continues to be a challenge. In addition to a chronic lack of data on the cliff face, vegetation presence and growth can bias our erosion measurements and limit our ability to detect geomorphic erosion by obscuring the cliff face. This paper builds on past research segmenting vegetation in three-band red, green, blue (RGB) imagery and presents two approaches to segmenting and filtering vegetation from the bare cliff face in dense point clouds constructed from RGB images and structure-from-motion (SfM) software. Vegetation indices were computed from …

Assessment Of Georgia’S Royal Catchfly (Silene Regia) Along A Forest-Edge Gradient In A Remnant Prairie Community, Megan Brooks

Master's Theses

Royal catchfly (Silene regia) is a perennial prairie forb known to grow in rocky, alkaline soils within tallgrass prairies of the eastern United States. S. regia is recorded from twelve states, including Georgia, and is now confined to fragmented habitats due to the loss of 95% of its natural environment. The species is now listed as critically imperiled in the state of Georgia. Attempts at reintroduction via outplanting have only shown limited success, necessitating more research on the environmental conditions in which this plant survives in its southern-most distribution. This study investigated the local ecological factors influencing the …

Current And Future Environmental Suitability For Bats Hosting Potential Zoonotic Pathogens In Rural Kenya, Ruut Uusitalo, Reilly T. Jackson, Tamika J. Lunn, Essi M. Kohonen, Joseph G. Ogala, Paul W. Wabala, Tarja A. Sironen, Kristian M. Forbes

Biological Sciences Faculty Publications and Presentations

Synanthropic bats live in close proximity to humans and domestic animals, creating opportunities for potential pathogen spillover. We explored environmental correlates of occurrence for a widely distributed synanthropic African bat, Mops pumilus—a species associated with potential zoonotic viruses—and estimated current and future environmental suitability in the Taita Hills region and surrounding plains in Taita–Taveta County in southeast Kenya. To project future environmental suitability, we used four Coupled Model Intercomparison Project Phase 6 general circulation models that capture temperature and precipitation changes for East Africa. The models were parameterized with empirical capture data of M. pumilus collected …

The Aquatic Microbial Environment Shapes The Gut Microbiota, Brain, And Behavior Of Larval Amphibians, Kyle Emerson

Electronic Theses and Dissertations

Microbial communities comprising bacteria, viruses, fungi, and protists live within and on the surfaces of animal hosts. These microbial communities exist in symbiosis with the host, and heavily influence host physiology, development, health, and fitness. Gut-dwelling microbes (i.e., gut microbiota) contribute to host neurodevelopment through a bidirectional Microbiota-Gut-Brain (MGB) axis. Evidence of the MGB axis has been primarily derived from studies that use germ-free (GF) models, which commonly display altered neurophysiology and behavior compared to conventionally raised counterparts. Almost all studies of the MGB axis have used mammalian models in a biomedical framework, leaving a knowledge gap regarding the role …

Using Dna Barcoding To Identify High-Priority Taxa (Hymenoptera: Ichneumonidae) From Great Smoky Mountains National Park, Emerie Landers, Brandon Claridge, Will Kuhn, Victoria Seymour, Hettie Peek, Scout Fluet, Jake Ramgren, Jake Phelps, Brayden Paulk, Lydia Cordner, Jeremy Blaschke

Biology Student Research

The All Taxa Biodiversity Inventory (ATBI) in Great Smoky Mountains National Park (GSMNP) seeks to document every species of living thing in the park. The ATBI is decades in progress, yet some taxa remain virtually untouched by taxonomists. Such "high priority" taxa include the hyper-diverse parasitoid wasp family Ichneumonidae. Despite the positive and multifaceted effects ichneumonids have on their environment, only a small percentage of those collected in the park have been identified as species, mostly to their complex morphology and overwhelming diversity. Recently, DNA barcoding has transformed biodiversity inventories, streamlining the process to be more rapid and efficient. To …

Soil And Organic Carbon Losses By Water Erosion In Coffee-Growing Areas In Southern Minas Gerais, Brazil, Derielsen Brandão Santana, Guilherme Da Silva Rios, Guilherme Henrique Expedito Lense, Felipe Gomes Rubira, Flávio Roberto Araújo Franceschi, Velibor Spalevic, Joaquim Ernesto Bernardes Ayer, Ronaldo Luiz Mincato

Turkish Journal of Agriculture and Forestry

Organic carbon performs essential functions in soils. Soils act as sources or sinks of atmospheric organic carbon. Agricultural management influences soil organic carbon, impacting climate change. One of the crops most vulnerable to climate change is coffee. Brazil is the world's largest coffee producer, with a predominance of management under a conventional system, with sloping terrain and the absence of conservationist practices. The absence of conservationist practices results in an increase in soil loss rates due to water management and carbon emissions, as well as a reduction in coffee production. This paper aimed to estimate soil and organic carbon losses …

Tree Rings Reveal The Transient Risk Of Extinction Hidden Inside Climate Envelope Forecasts, Margaret E. K. Evans, Sharmila M. N. Dey, Kelly A. Heilman, John R. Tipton, R. Justin Derose, Stefan Klesse, Emily L. Schultz, John D. Shaw

Wildland Resources Faculty Publications

Given the importance of climate in shaping species' geographic distributions, climate change poses an existential threat to biodiversity. Climate envelope modeling, the predominant approach used to quantify this threat, presumes that individuals in populations respond to climate variability and change according to species-level responses inferred from spatial occurrence data—such that individuals at the cool edge of a species' distribution should benefit from warming (the "leading edge"), whereas individuals at the warm edge should suffer (the "trailing edge"). Using 1,558 tree-ring time series of an aridland pine (Pinus edulis) collected at 977 locations across the species' distribution, we found …

Agricultural Groundcover Update May 2024, Justin Laycock

Natural resources published reports

• In May, over 9% (1,410,000 ha) of the arable farmland in the south-west of Western Australia had less than 50% vegetative groundcover, which is inadequate to prevent wind erosion.
• Northern grainbelt had the highest risk of wind erosion and over 26% of this farmland had inadequate groundcover, predominantly found on landscapes known for sandy soils.
• About 1.3% (208,900 ha) of arable land had a high to very high risk of wind erosion because groundcover was less than 30%. Half of this land was in the West Midlands Ag Soil Zone.

Agricultural Groundcover Update April 2024, Justin Laycock

Natural resources published reports

• In April, over 12% (1,876,000 ha) of the arable farmland in the south-west of Western Australia had less than 50% vegetative groundcover, which is inadequate to prevent wind erosion.
• Northern grainbelt had the highest risk of wind erosion and over 26% of this farmland had inadequate groundcover, predominantly found on landscapes known for sandy soils.
• About 1.5% (238,900 ha) of arable land had a high to very high risk of wind erosion because groundcover was less than 30%.

Occurrence Of Lotmaria Passim In Africanized And European Honey Bee, Apis Mellifera, Lineages From The United States, Mary-Kate Williams, Dylan Cleary, Allen Szalanski

Entomology and Plant Pathology Faculty Publications and Presentations

Honey bee populations in the United States have been under stress for the past several decades. Several internal parasites may contribute to this, including the trypanosome Lotmaria passim. It is unknown how widespread the honey bee parasite, L. passim, is in Africanized honey bee (AHB) populations in the United States. A total of 321 feral honey bee colony samples which had been previously recorded to be of Africanized origin using molecular diagnostics from California (n=3), New Mexico (n=46), Oklahoma (n=57), Texas (n=106), and Utah (n=109) were used in this study. Of these samples, a total of 15 (4.7%) …

Naturify 2300, Yarina Yiwei Dai

Masters Theses

In my art practice, I explore the interplay between human desires to manipulate and anthropomorphize nature, as seen in the technological augmentation of plants and living entities. This investigation delves into how this intersection, alongside empathy towards these creations, contributes to fears of uncontrollability and the risks of addiction and excessive dependence on technology.

Bioengineering and genetic modification have cultivated unprecedented developments, allowing humans to manipulate the fundamental building blocks of life. My research speculates on this technology further, modifying the genetic code of organisms and creating bioengineered wearable entities with enhanced traits or entirely new functionalities. The primary objective …

Association Of Tea And Coffee Consumption And Biliary Tract Cancer Risk: The Biliary Tract Cancers Pooling Project, Yu-Han Huang, Erikka Loftfield, Ilona Argirion, Hans-Olov Adami, Demetrius Albanes, Andrew T Chan, Veronika Fedirko, Gary E Fraser, Neal D Freedman, Graham G Giles, Patricia Hartge, Verena Katzke, Synnove F Knutsen, James Lacey, Linda M Liao, Juhua Luo, Roger L Milne, Katie M O'Brien, Ulrike Peters, Jenny N Poynter, Mark P Purdue, Kim Robien, Sven Sandin, Dale P Sandler, Veronica W Setiawan, Jae H Kang, Tracey G Simon, Rashmi Sinha, Trang Vopham, Stephanie J Weinstein, Emily White, Xuehong Zhang, Bin Zhu, Katherine A Mcglynn, Peter T Campbell, Mei-Hsuan Lee, Jill Koshiol

Faculty, Staff and Student Publications

Background and aims: Tea and coffee are widely consumed beverages worldwide. We evaluated their association with biliary tract cancer (BTC) incidence.

Approach and results: We pooled data from 15 studies in the Biliary Tract Cancers Pooling Project to evaluate associations between tea and coffee consumption and biliary tract cancer development. We categorized participants as nondrinkers (0 cup/day), moderate drinkers (>0 and < 3 cups/day), and heavy drinkers (≥3 cups/day). We estimated multivariable HRs and 95% CIs using Cox models. During 29,911,744 person-years of follow-up, 851 gallbladder, 588 intrahepatic bile duct, 753 extrahepatic bile duct, and 458 ampulla of Vater cancer cases were diagnosed. Individuals who drank tea showed a statistically significantly lower incidence rate of gallbladder cancer (GBC) relative to tea nondrinkers (HR=0.77; 95% CI, 0.64-0.91), and intrahepatic bile duct cancer (IHBDC) had an inverse association (HR=0.81; 95% CI, 0.66-1.00). However, no associations were observed for extrahepatic bile duct cancer (EHBDC) or ampulla of Vater cancer (AVC). In contrast, coffee consumption was positively associated with GBC, with a higher incidence rate for individuals consuming more coffee (HR< 3 cups/day =1.29; 95% CI, 1.01-1.66; HR≥3 cups/day =1.49; 95% CI, 1.11-1.99, Ptrend=0.01) relative to coffee nondrinkers. However, there was no association between coffee consumption and GBC when restricted to coffee drinkers. There was little evidence of associations between coffee consumption and other biliary tract cancers.

Conclusions: Tea consumption was associated with a lower incidence of GBC and possibly IHBDC. Further research is warranted to replicate the observed positive association between coffee and GBC.

Diversity, Distribution, And Determinants Of Bacterial Communities In Arctic Soil, Amna Khaleefa Alhemeiri

Theses

Arctic soils host diverse bacterial communities crucial for ecosystem functioning and nutrient cycling. Understanding the factors shaping their diversity and distribution is essential to assess ecosystem responses to climate warming. This study aimed to assess and compare bacterial diversity and community structure between high- and sub-arctic ecosystems and explore the environmental and climatic factors determining their distribution. We collected 16S rRNA gene amplicon sequence data from 999 samples of high- and sub-arctic soils. All the data was pre-processed and quality-controlled using a similar bioinformatics methodology, followed by statistical analyses including alpha and beta diversity assessments, and volatility analysis using QIIME2. …

Produced Water Management From Production Sites In The State Of Kuwait, Feras Adel Alsalem

Dissertations

Extraction of crude oil also produces large volumes of water, termed produced water (PW). PW is by far the most significant by-product in the process of extracting hydrocarbons from the subsurface. Consequently, managing PW has become a great concern to oil and gas producers. The increasing amounts of PW and more stringent environmental and safety regulations in regard to PW make more efficient treatment methods necessary, where sustainable long-term solutions for PW management need to be provided. The focus of this study is on PW from onshore operations as the majority of the oil and gas extraction operations (upstream processes) …