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Image Processing Techniques For Water Droplet Penetration Time And Contact Angle Estimation, Sai Balaji Jai Kumar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Water droplet behavior on soil surfaces plays a critical role in numerous environmental processes, including soil erosion, hydrological dynamics, and ecosystem health. Accurate characterization of soil water repellency, quantified by parameters such as water droplet penetration time (WDPT) and contact angles (WDCA), is essential for informed decision-making in agricultural management, forestry practices, and land-use planning. Despite the significance of these parameters, challenges exist in reliably estimating them due to the complex and dynamic nature of soil-water interactions. This thesis address challenges in estimating WDPT and WDCA, by leveraging state-of-the-art image processing techniques and machine learning algorithms. The research focuses on …

Phylogenetic And Biogeographic Patterns Of Devonian Proetid Trilobites, Katherine Jane Jordan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Ecological disruption events such as mass extinctions can result in the permanent alteration in clades and ecosystems. A pivotal time of change during the history of life on Earth can be seen in the Devonian Period. During this time, major transitions in marine and terrestrial system resulted in a different world at the end of the period in comparison to the beginning. One such group most heavily impacted were trilobites. Trilobites were reduced to one order by the end of the Devonian: Proetida. My dissertation focuses on phylogenetic, biogeographic, and paleocommunity patterns of this group, known as the last of …

Effects Of Climate Change On (Semi)-Arid Ecosystems In The Southwestern United States, Charlotte Van Der Nagel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate change is considered amongst the most severe threats to terrestrial and aquatic ecosystems globally. Ecosystems in the southwestern United States have specifically been impacted by intense drought conditions since 2000. Higher temperatures combined with altered precipitation stresses many ecosystems; however, ecosystem specific responses to such stressors may vary. Here, the effects of climate change on semi-arid ecosystems are analyzed for some of the most vulnerable ecosystems in the southwestern United States: lacustrine, riparian, and dryland ecosystems.

Lakes and reservoirs in arid environments often serve as drinking water sources and recreational areas where high water quality is essential. Climate change …

Tales In The Teeth: Using Isotopic Analysis To Understand The Paleoecology And Social Behavior Of Brontotheres Of The Intermountain Basins During The Middle Eocene, John Michael Michalski

All Graduate Reports and Creative Projects, Fall 2023 to Present

Isotopic analysis has been a common practice used in paleontology to study ancient ecosystems, and the lives of animals therein. Oxygen isotopic analysis is of particular importance not only because of its use in studying paleoecology, diet, and migration, but also its use in studying mountain elevation, and its impact on ancient ecosystems. I use stable oxygen isotopic analysis to study the habits and ecology of brontotheres from intermountain basins surrounding the Uinta Mountains of Utah and Wyoming, USA. I studied the oxygen isotopes from 16 fossil specimens of teeth, most of which belonged to brontotheres, including the genera Palaeosyops …

Economics - The Neglected Dimension Of Pasture Disease R&D, N D. Macleod

IGC Proceedings (1977-2023)

Pasture utilisation underpins a significant contribution of livestock industries to Australia’s economic well-being. Pasture disease represents a direct threat to these enterprises but the economic magnitude of this threat remains largely unknown as the contribution of agricultural economics to pasture disease R&D, management and policy making has been minimal to date. Some insights to explain this apparent neglect are highlighted and a suggestion is made for a multiple disciplinary approach to R&D.

The Effect Of Grazing On Etiolated Regrowth In Eight Grass Species, H A. Lardner, S.B M. Wright, R.D H. Cohen

IGC Proceedings (1977-2023)

Grazing by herbivores affects grass species both morphologically and physiologically. A grazing study was conducted on an irrigated pasture near Outlook, Saskatchewan, Canada during the summers of 1991 and 1992 to determine etiolated regrowth after grazing of reed canarygrass (Phalaris arundinacea L.), slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners subsp. trachycaulus), intermediate wheatgrass (Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp. intermedium), orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus beibersteinii Roem. & Schult.), smooth bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea (Schreb.) Wimm.) and timothy (Phleum pratense L.) in …

Forage And Animal Management Systems On Communal Rangelands In Arid And Semi-Arid Regions, Panjab Singh, A N. Ghosh

IGC Proceedings (1977-2023)

Grasslands and savannas, which comprise about 25% of the earth's land surface, are undergoing constant degradation, particularly in ar d and semi-arid regions. The rangeland resource is constantly sinking mainly because of its conversion to crop land, leaving farmer and pastorilist vulnerable to environmental extremes. This Paper presents the existing situation and the herbage and animal Product biomass of these regions. Climate and its impact on the Vegetation are discussed. Prevalent systems of rangeland use by sedentary and nomadic herdsman are considered and the constraints 0 the system are enumerated. Livestock 'rearing has been the most important occupation in these …

Autumn Grass Growth- The Effect Of Rest Interval, R Neilan, E G. O'Riordan, G Keane

IGC Proceedings (1977-2023)

The effect of closing dates (Experiment 1: August 1, August 14 and September 18) and grass regrowth interval (Experiment 2) on herbage yield in the autumn/winter and in the following spring were investigated on a previously grazed Lolium perenne sward. In Experiment 1, similar yields were obtained for the August 1 and August 14 closing. Yields decreased and the proportion of dead material increased from 0.19 to 0.61 between mid-October and late- December. In Experiment 2, dry matter yield increased linearly (P < 0.05) with rest interval up to 7 wks in swards closed in September. There was no significant yield advantage for rest intervals greater than 5-6 wks. It is concluded that accumulated autumn and spring yields showed increased DM production with the shorter regrowth intervals.

Responses Of Artemisia Herba-Alba Asso. And Its Associated Species To Grazing Frequency (Midelt, Morocco), M Mejjati Alami, O Berkat, C Bensalem

IGC Proceedings (1977-2023)

The objective of this study (conducted in 1994) was to assess the effects of season and grazing frequency (control, continuous, intermittent during 2 days per week) on vegetation attributes, and animal feeding behavior. Mean standing crop, for which Artemisia herba alba contributed 72%, attained 533 for the control while it was maintained at 394 and 322 Kg DM/ha, for the continuous and the intermittent grazing, respectively. Mean productivity of Artemisia herba alba varied according to treatment and had values of 5.3, 3.0 and 2.5 Kg DM/ha/day, under the ungrazed control, the continuous and the intermittent grazing regimes, respectively. Percent utilization …

Grazing Management Of An Italian Ryegrass Sward With Dairy Sheep In The Mediterranean Environment, M Sitzia, P P. Roggero, N Fois, G Molle

IGC Proceedings (1977-2023)

A grazing experiment was conducted in North-West Sardinia with the aim of testing the sward height as a mean to set up an efficient spring management of Italian ryegrass (Lolium multiflorum Lam.). Three fields were continuously grazed during spring 1992 by three groups of 12 dairy Sarda ewes, at three different sward heights (SH): 30 - 60 - 90 mm. The target sward height was obtained by continuously adjusting the field sizes. The results showed that the different grazing managements influenced the above ground biomass production and partitioning of the Italian ryegrass and the animal performances. During the vegetative …

Estimation Of Herbage Intake Of High Producing Milking Cows Under Intensive Grazing With A Supplementary Feeding Method In Northern Japan, K Ohiai, K Sudo, T Ikeda, T Honma

IGC Proceedings (1977-2023)

The objective of this study was to estimate the herbage intake and to assess a supplementary feeding method for high producing milk cows under intensive grazing. Eight high producing milking cows were grazed rotationally on perennial ryegrass (Lolium perenne L) dominant mixed pasture and on meadow fescue (Festuca elatior L) dominant mixed pasture, changing rotation period and grazing area ccording to seasonal pasture growth rate. Pasture intakes were estimated to be about 2% of body weight by TDN requirements estimation of animals. A supplementary feeding method is examined to be proper for high producing milking cows under …

Palatability Of Grasses And Grazing On Hungarian Grassland, Z Barcsak, I Kertesz, L Szeman

IGC Proceedings (1977-2023)

Grasslands provide the most basic and cheapest forage diet for cattle. The palatability studies were carried out on pure and mixed swards sown in 1990 on the GATE experimental farm. The studies involved the following 12 species: Lolium perenne, Trifolium repens, Festuca arundinacea, Festuca rubra, Poa pratensis, Festuca pratensis, Bromus inermis, Phalaris arundinacea, Lotus corniculatus, Agropyron crystatum, Dactylis glomerata and a mixed sward. During the study the morning and afternoon grazings were investigated with the involvement of 60 Limousin cattle. The following observations were made: 1. On the basis of our ethological observations regarding the bite rates the animals found …

Selective Sheep Grazing In An Heterogeneous Wheatgrass Dominated Pasture Related To Stocking Rate, G L. Siffredi, M A. Brizuela, M S. Cid, C Cangiano

IGC Proceedings (1977-2023)

It has been hypothesized that patch and community selection are driven by forage quality and/or quantity. We assess the relationship between vegetation characteristics and community and patch selection by sheep under continuous grazing at different stocking rates in an heterogeneous pasture. Our results suggest that when communities strongly differed in nutritive value sheep recurrently select the higher quality community in spite of its low biomass. However, sheep do not completely exclude the poorer quality community, generating a patchy vegetation pattern.

Grazing Management Of Elephant-Grass For Milk Production, F Deresz, L L. Matos

IGC Proceedings (1977-2023)

The objectives of these experiments were to study the effects of three resting periods (RP) of elephant-grass pasture on milk production and composition of Holstein-Zebu cows. These trials were carried out during two consecutive rainy seasons (December to May) using 24 cows in each year. They were randomly assigned by blocks according to milk yield and live weight (LW) to four treatments: 30- day RP with no concentrate (30N), 30-day RP with concentrate (30C), 36 and 45-day RP with C (36C and 45C) in the first year. In the second year the treatments were: 30C, 30N, 36N and 45N. Concentrate …

Comparison Of Yield, Forage Quality And Persistence Of 11 Grasses Grown With Irrigation In A Semi-Arid Climate, D E. Glover, G A. Kielly, R H. Cohen, P G. Jefferson

IGC Proceedings (1977-2023)

Nutritive quality of many grass species used for forage in the Northern Great Plains of Canada and the United States is not well documented, especially at different maturity stages. This study compared agronomic and forage quality characteristics of eleven grasses common to Saskatchewan. Botanical separation and quality analysis was undertaken at three growth stages. Meadow Brome (Bromus riparius), Russian Wildrye (Psathyrostachys juceus) and Altai Wildrye (Elymus angustus) were shown to have high leaf to stem ratios which corresponded with high protein levels. Separations showed persistence of Reed Canarygrass (Phalaris arudinaceus), Creeping Foxtail …

The Effect Of Grazing On Leaf Development In Eight Grass Species, H A. Lardner, S.B M. Wright, R H. Cohen

IGC Proceedings (1977-2023)

Grazing by herbivores affects grass species both morphologically and physiologically. A grazing study was conducted on an irrigated pasture near Outlook, Saskatchewan, Canada during the summers of 1991 and 1992 to determine morphological development of regrowth of reed canarygrass (Phalaris arundinacea L.), slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners subsp. trachycaulus), intermediate wheatgrass (Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp. intermedium), orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus beibersteinii Roem. & Schult.), smooth bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea (Schreb.) Wimm.) and timothy (Phleum pratense L.) in order to …

The Effect Of Slurry And Dirty Water Application To Swards On Grazing Behaviour In Dairy Cows, S Danby, J A. Laws, P D. Penning, B F. Pain, E Owen

IGC Proceedings (1977-2023)

In preference tests using pairs of turves in boxes (treated and control), dairy cows were more averse to surface spread than shallow injected slurry and more averse to slurry than dirty water. Effects of slurry persisted for up to 6 weeks, with fewer bites and less herbage removed from treated swards compared to control swards. Aversion to slurry may be decreased by injection. Effects of dirty water persisted for only 14 days.

Applications Of Height-Based Grazing Management In Mixed Swards, A Singh, J E. Johnston, E A. Clark

IGC Proceedings (1977-2023)

Grazing efficiency and livestock performance were compared on swards rotationally grazed down to either 50 or 100 mm for three years. With a fixed entry height of 200-250 mm, standing swards of mixed grasses and white clover (Trifolium repens L.) were stratified into 50 mm vertical layers both pre- and post-grazing. Through four or five cycles of grazing each year for three years, a fixed entry height range stabilized total standing herbage at 3250 to 3690 kg OM ha-1. Organic matter on-offer above 100 mm was 36, 45, and 43% of total standing herbage in the three years, compared …

Ingestive Behavior Of Fistulated And Intact Sheep Grazing Grass And Legumes Indoors And Outdoors, Y M. Gong, J Hodgson, M G. Lambert

IGC Proceedings (1977-2023)

Components of short-term ingestive behaviour were recorded for fistulated and intact sheep grazing turves in indoor crates, and for esophageal-fistulated sheep grazing swards in situ in outdoor cages. Perennial ryegrass, orchard grass and white clover at vegetative and reproductive growth stages were offered to the sheep. Bite weight, depth, area and volume did not differ between sheep grazing indoors and outdoors, nor between intact and fistulated sheep. Bite rate of fistulated sheep was slower indoors than outdoors (25.3 versus 32.1 bites/min), and intact sheep had a higher biting rate (36.7 versus 25.3 bites/min) than fistulated sheep. Bite weight was over-estimated …

Dairy Production From Pasture In Southern China, P.N P. Matthews, J Hodgson, A.C P. Chu, W L. Jiang, C B. Luo

IGC Proceedings (1977-2023)

This paper covers the development of dairy production systems as part of the UNDP funded Agro-grasslands Systems Development Project in Guizhou Province, China. The basic philosophy for the project was for local adaptation of New Zealand technology for developing dairy production systems based on pastures. The dairy production systems were established and the outputs of the project successfully achieved. Net incomes of smallholder farmers increased from a baseline of RMB $140 to RMB $1740 per annum over a three year period. Based on the experienced gained in setting up these systems local researchers, administrators, extension personnel and smallholders were able …

Trace Mineral Status Of Beef Cattle Grazing Semiarid Rangelands Of North Mexico, J R. Kawas, G T. Armienta, E Olivares, O Torress, J J. Kawas, F Garza

IGC Proceedings (1977-2023)

Trace mineral concentrations of soil, forage and serum of range cattle of the northeast Mexico state of Nuevo Leon were determined in both wet and dry seasons of 1992. For each season, collections were made at twenty-four ranches within eleven counties of three regions. A total of 220 soil, 680 forage and 220 blood samples were collected and analyzed. No differences (P<0.05) between regions were obtained for Zinc (28.0 to 34.9 ppm) or Copper (4.4 to 5.4 ppm). Molybdenum concentrations were greater in the northern (2.1 ppm) than in the central (1.6 ppm) or southern (1.5 ppm) regions. Considering the critical levels in forages for Zinc (30 ppm) and Copper (10 ppm) reported by the National Research Council (1984), Zinc concentrations may be marginally deficient, whereas Copper concentrations were deficient in all three regions, in both seasons, and in grasses and woody species.

Forage-Based Seasonal Dairying In South Louisiana, H A. Deramus, L Labbe, K Ingawa, W A. Atkinson, M J. Simon, J D. Roussel

IGC Proceedings (1977-2023)

The effects on the net profit and total milk production were compared using two levels of grain supplementation and forage-only feeding in a program of seasonal dairying in South Louisiana using management intensive grazing. Treatments were 8 kg grain, 4 kg grain, and 0 grain supplementation. Annual ryegrass (Lolium multiflorium) and clovers (Trifolium incarnatum, and T. Alexandrinum) were grazed intensively with 51 multiparous Jersey and Holstein cows in mid-lactation in 1993-1995. Milk production, milk fat, milk protein, and blood urea nitrogen were measured. Milk and protein models were all highly significant for all classes. Daily milk …

Influence Of Sheep And Goats On The Natural Succession, H D. Matthes, S Demise, M Schubert, H Mohring

IGC Proceedings (1977-2023)

A study was conducted to examine the effect of extensively-grazed pasture on the botanical composition. The trails were carried out in the year 1992 to 1995. For the study different breeds of sheep with the stocking rate of 30 sheep with their lambs / 2.6 ha were used. For the mixed-grazing a ratio of 20 sheep and 10 goats with their lambs / 2.6 ha were used. It is not possible to control all problem species with the help of sheepgrazing only. In contrast to that, it was concluded that goats grazed off all problem species quite effectively. Botanical composition …

Influence Of Different Breeds Of Pigs To The Natural Succession, H D. Matthes, A.C D. Micklich, G Dietl, H Mohring, W Jentsch

IGC Proceedings (1977-2023)

The aim of this study was to find out the effect of pigs on the natural succession. We used 4 different breeds of pigs for our investigations. Because of the grazing behaviour and their rooting activity the total number of plants increased up to 30%. But the vegetation quickly returned to conditions prior to rooting, if the rooting activity fails to happen. Rooting activity of pigs on floodplain soil and following grazing in the next spring after rooting permits seeds of different species of plants to germinate and develop in the plant free areas. These plants often have little chance …

Road Mitigation Structures Designed For Texas Ocelots: Influence Of Structural Characteristics And Environmental Factors On Non-Target Wildlife Usage, Anna Rivera Roy, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

Roads negatively impact wildlife through habitat fragmentation, loss of habitat connectivity, and wildlife-vehicle collisions, thus road mitigation structures, such as wildlife crossing structures (WCS), wildlife guards (WG), and fencing are commonly used to address this issue all over the world, including in the United States. In South Texas, such structures were built or modified along a State Highway in an effort to address road mortality for the endangered ocelot (Leopardus pardalis) and non-target wildlife species. The goal of this study was to examine temporal changes in wildlife interactions with WCS and WG during and after their construction and …

Red Harvester Ant, Pogonomyrmex Barbatus, Nests Impact Soil Compaction But Not Temperature In Peri-Urban Habitats Of The Lower Rio Grande Valley, Geovanni Hernandez, Hannah J. Penn, Richard Cano, Lilly Victoria Elliott-Vidaurri, Robin A. Choudhury

School of Earth, Environmental, & Marine Sciences Faculty Publications

Ants are vital ecosystem engineers that can influence soil properties, subsequent soil processes, and associated biota via underground nest construction. Harvester ants consume seeds and are often found in arid areas. They frequently alter the soil chemistry and bulk density of the soils in and around their nest sites. Many species of harvester ants also intentionally remove vegetation around their nest openings, which creates cones or discs of bare soil that may further alter soil temperatures. However, much of the work to study the impacts of harvester ants on soil properties has occurred in shrubland and grassland settings rather than …

Populations Of The Stygobiotic Amphipod Palearcticarellus Pusillus (Martynov, 1930) Maintain Genetic Connectivity Between The Mountain Springs And The Deep Bottom Habitats Of Lake Teletskoye (Altai Mountains, Russia), Ivan Marin, Liubov Yanygina, Svetlana Ostroukhova, Dmitry Palatov

International Journal of Speleology

The diversity of underground fauna is often associated with the presence of karst areas, which have extensive underground cavities and connecting channels. Non-karst areas, however, make up a larger portion of the planet’ surface, and our understanding of the distribution and dispersal abilities of underground fauna in these areas currently remains limited. During a recent study of the diversity of stygobiotic crustaceans in the mountain streams of the Kurai Mountain Range (Altai, Russia), a small-sized species of crangonyctid amphipod, Palearcticarellus pusillus (Crustacea, Amphipoda, Crangonyctidae) was found in high-altitude springs. This species has been previously known only from deep-water habitats in …

Infograz: A Data Base For Tropical Grazing Systems, K G. Rickert, J Carter, C K. Mcdonald

IGC Proceedings (1977-2023)

INFOGRAZ is a prototype of a comprehensive relational database that describes the management of, and stores information from, grazing experiments in northern Australia associated with the wool, beef, and dairy industries. It provides permanent storage and public access for detailed measurements on climate, soil, plants, and animals, which are a valuable resource for future pasture scientists and computer modellers of grazing systems. Thus it will prevent the detailed observations being lost with the passage of time. Verified data from each experiment are stored in tables which can be distributed on CD-ROM, along with procedures to access the data and use …

The Hydrological Impacts Of Woody Plant Encroachment On Coastal Tallgrass Prairie Of Texas, Zhiwei Guo

LSU Master's Theses

Globally, woody plant encroachment into grassland and savanna ecosystems impacts the hydrological functions of grasslands and associated wetlands. In the coastal tallgrass prairie of Texas, encroachment of woody plants has altered vegetation structure, but the hydrological impacts are poorly understood. In this study, I evaluated and quantified how woody plant encroachment affects hydrological processes on the pimple mounds and inter-mound freshwater marsh, including precipitation partitioning, infiltration in the vadose zone, groundwater recharge, and water volume in the inter-mound marsh. I randomly selected three pimple mounds with woody plants and three pimple mounds with tallgrass w to quantify hydrologic processes. The …

Effects Of Two Grazing Conditions On The Reproductive Achievement Of Male Alpaca In The Northern Peru Grasslands, C Pinares, E Malpartida, S Cortez

IGC Proceedings (1977-2023)

Alpaca have recently been introduced to the northern Peru grasslands (Jalca). Effects of two systems of grazing management, co-grazing (with sheep) under fair grassland condition (CGFC) versus exclusive grazing under good grassland condition (EGGC), upon the reproductive achievement was examined from the 6th to the 16th month of age. Each system involved 20 Huacaya animals, managed by individual herders. Availability of herbage preferred by alpaca (HMA) and animal measurements (herbage intake, liveweight, testicle size, penis release from preputial attachments, plasma testosterone) were monitored monthly. Puberty, judged by the penis release from the preputial attachments, was achieved by 7 …