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2021

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Articles 481 - 510 of 16206

Full-Text Articles in Earth Sciences

Effect Of Water-Soluble Browning Products In Heated Herbages On Rumen Microorganisms, E. Touno, A. Takenaka, T. Kondo, O. Tanaka, M. Murai Oct 2021

Effect Of Water-Soluble Browning Products In Heated Herbages On Rumen Microorganisms, E. Touno, A. Takenaka, T. Kondo, O. Tanaka, M. Murai

IGC Proceedings (1977-2023)

When feed is heated, browning can occur. This browning is detrimental to both the value of feed and physiological functioning of the animal. Browning occurs when polymeric substances are produced during the Maillard reaction. Indigestible soluble Maillard reaction products could affect nitrogen utilization by ruminants. A method has been established for isolation of water-soluble browning products using a reversed phase column. In the present work, the effect of water-soluble browning products isolated from heated herbage on rumen microorganisms was investigated. A solution of browning products was added to the medium 10 to obtain final concentration of 0, 0.5 and 2.0 …


Comparison Of Summer Forages And The Effect Of Nitrogen Fertilizers On Brassica Forages In Tasmania, A. A. Salardini, R. J. Eckard, D. R. Franks Oct 2021

Comparison Of Summer Forages And The Effect Of Nitrogen Fertilizers On Brassica Forages In Tasmania, A. A. Salardini, R. J. Eckard, D. R. Franks

IGC Proceedings (1977-2023)

Summer forage crops, and in particular Brassica spp., have become increasingly popular in dairy production systems in Tasmania. Field experiments were conducted for 3 years in northwestern Tasmania, in the spring/summers beginning in 1995. The study aimed to compare yield and quality of Brassica and Poaceae forages and the response of Brassica species to nitrogen (N) (50, 100 and 200 kg N/ha) and irrigation.

The average total yields of dryland (rainfed) crops in 1995 to 1997 experiments, were turnip (Brassica rapa) 9.3 t/ha, rape (B. napus) 5.9 t/ha, oats (Aevena sativa) 5.2 t/ha, kale …


Maturity And Fertilization Effects On Leaf Blade Tissue Percentages Of Contrasting Fescue Cultivars, L. B. Tempone, M. S. Cid, M. A. Brizuela, M. C. Nunciari, M. G. Cendoya Oct 2021

Maturity And Fertilization Effects On Leaf Blade Tissue Percentages Of Contrasting Fescue Cultivars, L. B. Tempone, M. S. Cid, M. A. Brizuela, M. C. Nunciari, M. G. Cendoya

IGC Proceedings (1977-2023)

Palenque Plus and Ceres Torpedo are tall fescue (Festuca arundinacea Schreb.) cultivars available to the animal production systems in the humid Pampean Region of Argentina. They differ in growth cycle and morphological characteristics. At vegetative stage, Torpedo leaves are fine and tender, which suggests that their percentages of slowly digestible and indigestible tissues (SDIT) should be low. In this study we 1) explored the effects of phenological stage and nitrogen fertilization on leaf blade tissue percentages of both cultivars, using an ordination multivariate technique, and 2) evaluated the effects of these factors on the percentage of SDIT. Our results …


Different Harvest Schedules To Prepare Deferred Forage From C4 Grasses In Córdoba, Argentina, M. R. Steinberg, E. F. Nienstedt, H. A. Valdez, J. C. Coraglio, C. A. Vieyra, P. A. Minuzzi Oct 2021

Different Harvest Schedules To Prepare Deferred Forage From C4 Grasses In Córdoba, Argentina, M. R. Steinberg, E. F. Nienstedt, H. A. Valdez, J. C. Coraglio, C. A. Vieyra, P. A. Minuzzi

IGC Proceedings (1977-2023)

From 1995 until 1999 a trial was done in the fields of the Universidad Nacional de Córdoba with four C4 forage grasses. These fields lie in the subtropical and semiarid region of Argentina. This research aimed to identify forage species that could be used as deferred forage for the drier and cooler winter season. Four species of C4 grasses were used: Rhodesgrass (Chloris gayana Kunth), Gatton (Panicum maximum), coloratum (Panicum coloratum) and digitgrass (Digitaria eriantha), respectively. Two growing periods were used: full season growth (FS) and half season regrowth (HS), in both cases …


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No abstract provided.


Boron Fertilization Effects On Nutritive Parameters Of Alfalfa, F. M. Rouquette Jr., V. A. Haby, J. O. Fritz, M. Collins Oct 2021

Boron Fertilization Effects On Nutritive Parameters Of Alfalfa, F. M. Rouquette Jr., V. A. Haby, J. O. Fritz, M. Collins

IGC Proceedings (1977-2023)

With early pre-plant incorporation of limestone to raise soil pH to 6.8 to 7.0, alfalfa (Medicago sativa L.) may be grown successfully on acid, Coastal Plain, sandy loam soils. Fertility and forage quality for hay and/or grazing require alternative management of alfalfa on these Coastal Plain soils. A two-year experiment evaluated alfalfa fertilized with three rates of boron to quantify effects on nutritive entities, especially fiber components. On a whole-plant basis in year 1, only crude protein was increased (P < .05) at one of six harvest dates. In year 2, chemical analyses of leaf-stem components indicated consistent increases in crude protein of leaf fractions at each harvest (P < .05), reduction in neutral detergent fiber at three harvest dates (P < .06), and reduced lignin (P < .07) at the final harvest. Stem sections were affected by rate of boron at only the June harvest with an increase in crude protein (P < .05). Rate of boron fertilization had indirect effects on nutritive value (crude protein) by either delaying physiological maturity or enhancing nitrogen fixation in leaves, and had a direct negative effect on certain fiber components.


The Role Of Grass Feeding In Improving Oxidative Stability And Increasing Vitamin B12 Content Of Beef And Veal, V. Pastushenko, H.-D. Matthes, H. Heinrich, Z. Holzer, T. Prokopyuk Oct 2021

The Role Of Grass Feeding In Improving Oxidative Stability And Increasing Vitamin B12 Content Of Beef And Veal, V. Pastushenko, H.-D. Matthes, H. Heinrich, Z. Holzer, T. Prokopyuk

IGC Proceedings (1977-2023)

The objective of this study was to investigate the influence of grass feeding of cattle on the decontamination capacity against free radical (DCAFR) and vitamin B12 content of beef and veal. The meat samples from intensively (26 cattle, final weight 485±9 kg, concentrate feeding) and ecologically (25 heifers, final weight 472±32 kg, and 28 calves, final weight 260±24 kg, pasture grazing) managed cattle groups were investigated. The DCAFR was colorimetric assessed by examining damage to 1.4 benzoquinone. Vitamin B12 was analyzed by high performance liquid chromatography. Data indicate that the oxidative stability of meat samples from ecological management …


Nitrate Accumulation In A Sorghum-Sudangrass Hybrid As Influenced By Nitrogen Fertilization, A. Elgersma, I. Y. Tecle, T. Provin Oct 2021

Nitrate Accumulation In A Sorghum-Sudangrass Hybrid As Influenced By Nitrogen Fertilization, A. Elgersma, I. Y. Tecle, T. Provin

IGC Proceedings (1977-2023)

The effect of nitrogen (N) fertilization and plant stage on nitrate accumulation was studied in a sorghum-Sudan grass hybrid. Grass cv. Dynagrazer was sown at the experimental site of Texas A & M University. Six N levels were applied (0, 112 … 672 Kg. N ha-1). Nitrate concentrations were determined in three harvests, 5– 7 weeks after planting. Maximum levels were 2.1, 3.5 and 4.6 g nitrate-N kg-1 DM, respectively, which is beyond the safe limits for animal consumption. The plots were cut at heading. Regrowth took place on residual N. Nitrate-N accumulation was lowest in the …


Effect Of Maceration On In Sacco Degradability And Energy Content Of Low-Moisture Round Bale Alfalfa Silage, K. Nonaka, S. Kume, T. Ohshita Oct 2021

Effect Of Maceration On In Sacco Degradability And Energy Content Of Low-Moisture Round Bale Alfalfa Silage, K. Nonaka, S. Kume, T. Ohshita

IGC Proceedings (1977-2023)

The aim of this study was to determine the effect of maceration on in sacco degradability and energy content of low-moisture alfalfa (Medicago sativa L.) silage. The results of two treatments were compared: 1) maceration, in which the alfalfa was processed through a large- scale forage mat maker prior to wilting to approximately 50% DM content (FM treatment), and 2) conventional conditioning, in which the alfalfa was tedded and wilted to the same DM content as that in the FM treatment (CC treatment). Silage bales were chopped in 20-mm pieces for each experiment. In sacco degradabilities of DM, CP …


Efficiency Of Nitrogen Use In Dairy Cows Grazing Ryegrass With Different Water Soluble Carbohydrate Concentrations, L. A. Miller, D. H. Baker, M. K. Theodorou, J. C. Macrae, M. O. Humphreys, Nigel D. Scollan, J. M. Moorby Oct 2021

Efficiency Of Nitrogen Use In Dairy Cows Grazing Ryegrass With Different Water Soluble Carbohydrate Concentrations, L. A. Miller, D. H. Baker, M. K. Theodorou, J. C. Macrae, M. O. Humphreys, Nigel D. Scollan, J. M. Moorby

IGC Proceedings (1977-2023)

This experiment is one of a series designed to investigate the efficiency of nitrogen (N) use in Holstein-Friesian dairy cows grazing perennial ryegrass (Lolium perenne) which has been bred to express high water soluble carbohydrate (WSC) concentrations. Animals grazed either a High Sugar (HS) grass or a Control (C) variety chosen on the basis of heading date compatibility. Dry matter (DM) intakes were estimated using herbage mass. Milk yields, milk constituent concentrations and plasma concentrations of b-hydroxybutyrate, glucose, total protein, albumin and urea were also measured. Forage DM intakes were similar for the two grasses. However, because of …


Mgrre_Pureoilscouttickets_Pinder._2_21127023530000, Mgrre Oct 2021

Mgrre_Pureoilscouttickets_Pinder._2_21127023530000, Mgrre

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No abstract provided.


Three-Dimensional Intrusion Geometries In The Monogenetic San Rafael (Utah) Sub-Volcanic Field Revealed By Nonlinear Inversion Of Magnetic Anomaly Data, Troy A. Berkey Oct 2021

Three-Dimensional Intrusion Geometries In The Monogenetic San Rafael (Utah) Sub-Volcanic Field Revealed By Nonlinear Inversion Of Magnetic Anomaly Data, Troy A. Berkey

USF Tampa Graduate Theses and Dissertations

Distributed volcanic fields are common on Earth and nearby planetary bodies. Unlike their central-vent counterparts, these volcanic centers are comprised of many individual basaltic magmatic dikes, which are often only expressed at the surface in the form of vents, domes, and lava flows. In situ imaging of the shallow (<1 km) subsurface can reveal important details about the 3D geometry of fissure systems that feed distributed eruptive centers, with implications for the nature of these eruptions: their mass flow rates, explosivity, durations, and volcanotectonic interaction. Luckily, dikes, sills, conduits and related near-surface structures tend to carry high remnant magnetizations, creating magnetic anomalies at the surface where sufficient magnetic contrast exists with the host rocks they intrude. In the San Rafael Sub-volcanic field (SRSVF), basaltic dikes intrude fractured and horizontally bedded Jurassic sandstones, now eroded to a depth of about 800 m beneath the paleo-surface. Detailed mapping and profiles with a Cs-vapor magnetometer reveal far more complex anomalies than can be attributed to simple planar dikes, including: sills, buds, and domes. We image these geometries using MagCube-parallel, an open-source nonlinear inversion code we developed that models complex geometry with multiple (<= 1,000) vertical-sided prisms. I show one normally polarized fissure system to include along strike: An ~3-14 m thick, ~50 m wide dome-like feature or laccolith at depths of ~9-20 m, a roughly vertical conduit ~15 m thick, ~36-50 m wide, at ~1-16 m depth near the center of the mapped fissure-like system, and a ~8-48 m. wide dike at ~2-17 m depth that is <1-6 m thick, with reducing magnitude northward. While model depth and thickness vary with magnetization contrast, the main geometric relationships do not. Magnetic mapping of a nearby fissure reveals the same types of structures. The implication of these structures is that the small-volume fissure eruptions were likely pulsatory, with episodes of horizontal intrusion of sills, and sufficient time to develop gravitational instabilities.


Maris: Scalable Online Scenario Development Tool For Rangeland Conservancy Managers Using High Spatial-Temporal Resolution Carrying Capacity Maps And Livestock Market Data, L. G. J. Boerboom, R. O. Ohuru, A. G. Toxopeus, W. Nieuwenhuis, C. A. J. M. De Bie, P. K. Mwangi, M. L. Schouwenburg, R. L. G. Lemmens Oct 2021

Maris: Scalable Online Scenario Development Tool For Rangeland Conservancy Managers Using High Spatial-Temporal Resolution Carrying Capacity Maps And Livestock Market Data, L. G. J. Boerboom, R. O. Ohuru, A. G. Toxopeus, W. Nieuwenhuis, C. A. J. M. De Bie, P. K. Mwangi, M. L. Schouwenburg, R. L. G. Lemmens

IGC Proceedings (1977-2023)

Although the management of livestock numbers within the bounds of carrying capacity of African rangelands is a way to manage risks, both scientists and practitioners, caution against a momentary and local use of carrying capacity as a management indicator. Carrying capacity should be seen in wider spatial and temporal/seasonal context as well as in a social and economic context. Given the large numbers of conservancies across Kenya, and its Maasai Mara region in particular, with many more landowner members, it is difficult for conservancies’ managers to contextualize phenomena such as carrying capacity and market price over space and time.

We …


Assessing The Impacts Of Different Initiatives On The Rehabilitation Of Pastoral And Silvopastoral Ecosystems: Big Data Oriented Approach, Said Moukrim, Said Lahssini, Mustapha Naggar, K. Menzou, H. Mharzi-Alaoui, A. Labbaci, L. Rhazi Oct 2021

Assessing The Impacts Of Different Initiatives On The Rehabilitation Of Pastoral And Silvopastoral Ecosystems: Big Data Oriented Approach, Said Moukrim, Said Lahssini, Mustapha Naggar, K. Menzou, H. Mharzi-Alaoui, A. Labbaci, L. Rhazi

IGC Proceedings (1977-2023)

Moroccan forests, through the provision of goods and ecosystem services, underpins benefits to local communities and play a crucial role for rural area development. The legal framework recognizes to people, living near public forests, the right to graze their domestic livestock. Over the years, the grazing pressure is at levels far beyond the forestland’s carrying capacity throughout the country. Such pressure has been demonstrated as the main cause of forest cover loss and land degradation in Morocco and still threatening the sustainability of forests. To reduce the heavy grazing pressure on forest ecosystems and ensure their regeneration, several initiatives have …


The Role Of Indigenous Knowledge In The Effective Collective Management Of The Communal Rangelands, A. Finca, S. Linnane, D. Getty, J. H. Slinger Oct 2021

The Role Of Indigenous Knowledge In The Effective Collective Management Of The Communal Rangelands, A. Finca, S. Linnane, D. Getty, J. H. Slinger

IGC Proceedings (1977-2023)

Numerous scientific studies have highlighted the complexities associated with the collective management of communal rangelands. To date, policy interventions in rangelands have largely ignored people’s traditional ways of managing, with adverse effects on rangeland productivity. Thus, local knowledge has not been considered in spatial planning, despite the fact that local rural communities are often repositories of key indigenous knowledge. Hence this study set out to evaluate the role of indigenous knowledge in the management of the communal rangeland in Cata and Guquka, now and in the future. This was achieved through the use of Participatory GIS (PGIS), specifically participatory mapping …


Land Users – Land Watchers, J. H. Stefánsson, B. Marteinsdóttir Oct 2021

Land Users – Land Watchers, J. H. Stefánsson, B. Marteinsdóttir

IGC Proceedings (1977-2023)

GróLind is a collaborative project with the aim of monitoring Icelandic vegetation and soil resources. It was founded in 2017 by the Icelandic National Associations of Sheep Farmers, the Farmers Association of Iceland, Ministry of Industries and Innovation, and the Soil Conservation Service of Iceland. GróLind is a collaborative project and cooperation with stakeholders, such as the science community, landowners, and others, is a fundamental concept in the project.

In this project, the state of vegetation and soils are evaluated. Currently, a citizen science project is being developed within GróLind, in which land-users will annually monitor, using a mobile app, …


Silvopastoral Strategy And Sustainable Management Of Forests In Morocco, Mustapha Naggar, Said Lahssini, Said Moukrim, Anass Legdou Oct 2021

Silvopastoral Strategy And Sustainable Management Of Forests In Morocco, Mustapha Naggar, Said Lahssini, Said Moukrim, Anass Legdou

IGC Proceedings (1977-2023)

In Morocco, forests act as a grazing reserve all year long and in a normal year produce 1.5 billion feed units, i.e. 17 % of the national forage assessment. The pastoral question is one of the factors involved in the desertification of forested areas against a bioclimatic background where more than 93% of the national territory is arid. In 2016, the Water and Forestry Department in cooperation with its partners, devised a nation-wide sylvo-pastoral strategy. The approach adopted consists in sustainably managing sylvo-pastoral resources over the long term based on good governance of all goods and services offered by forested …


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No abstract provided.


The Importance Of Lithologic Variability And Stratigraphic Architecture In The Development Of Eogenetic Karst Systems, Nicholas J. Soto-Kerans Oct 2021

The Importance Of Lithologic Variability And Stratigraphic Architecture In The Development Of Eogenetic Karst Systems, Nicholas J. Soto-Kerans

USF Tampa Graduate Theses and Dissertations

Integrative characterizations of karst systems on low-lying eogenetic carbonate platforms are rare and often limited to areas of direct observation where caves can be entered and explored. Because hydraulic properties of eogenetic limestones have been implicitly assumed to be homogeneous, classical models of carbonate island karst development stressed the importance of geochemical interfaces in controlling cave and vug development. These studies have explained the largest cavern systems as results of either 1) mixing dissolution at platform margins or 2) microbially-mediated dissolution processes at water tables.

New data from core descriptions and wireline logs obtained in 18 boreholes drilled in the …


Impacts Of Wood Fuel Uses On Forest Cover: The Case Of Semiarid Areas In Northern Tanzania, Debora J Mahushi, Revocatus L Machunda, Talam E Kibona Oct 2021

Impacts Of Wood Fuel Uses On Forest Cover: The Case Of Semiarid Areas In Northern Tanzania, Debora J Mahushi, Revocatus L Machunda, Talam E Kibona

Tanzania Journal of Science

Satellite images for the years 1987, 1997, 2002 and 2017, and questionnaire surveys were used to assess energy sources and demands as well as the impacts of wood fuel use to forest cover changes in Meru and Mwanga Districts. The major energy sources identified include cow dung cake, firewood, charcoal, liquefied petroleum gas and biogas. The total energy demands from these sources were 1400 (in Meru), 6289, 724 and 21 kg per day, respectively. The amount of biogas was not quantified since the reactors were constructed locally with no reading meter. Analysis from Landsat images showed variations in forest cover. …


Effects Of Agroforestry Practices On Soil Properties In The Drylands Of Eastern Kenya, Nicholas Syano Mutuku, Moses M. Nyangito, Geoffrey Kironchi, Oliver Vivian Wasonga Oct 2021

Effects Of Agroforestry Practices On Soil Properties In The Drylands Of Eastern Kenya, Nicholas Syano Mutuku, Moses M. Nyangito, Geoffrey Kironchi, Oliver Vivian Wasonga

IGC Proceedings (1977-2023)

Drylands, which are home to about 2 billion people face a myriad of problems among them low land productivity. Agroforestry is one of the land use practices that is perceived to be sustainable with beneficial effects on soil properties. However, the effects of agroforestry practices on soils especially in the drylands have rarely been quantified and studied in details. The study determined the effects of selected agroforestry practices on soil properties in Makueni County of Kenya where agroforestry has been promoted by various organizations. Four soil samples were collected at 0-15cm, 15-30cm, 30-45cm and 45-60cm depths in a zigzag pattern …


Adaptive, Multi-Paddock, Rotational Grazing Management: An Experimental, Ranch-Scale Assessment Of Effects On Multiple Ecosystem Services, D. J. Augustine, J. D. Derner, L. M. Porensky, H. Wilmer, María E. Fernández-Giménez, David D. Briske Oct 2021

Adaptive, Multi-Paddock, Rotational Grazing Management: An Experimental, Ranch-Scale Assessment Of Effects On Multiple Ecosystem Services, D. J. Augustine, J. D. Derner, L. M. Porensky, H. Wilmer, María E. Fernández-Giménez, David D. Briske

IGC Proceedings (1977-2023)

Decisions on how to move livestock in space and time are central to rangeland management. Despite decades of small-scale research, substantial uncertainty exists regarding the relative importance of cattle stocking rates per se, versus the movement of cattle in both space and time, in achieving desired vegetation and livestock outcomes at scales relevant to livestock producers. We report on a ranch-scale experiment comparing effects of collaborative, adaptive, multi-paddock, rotational management (CARM) versus more traditional, season-long, continuous rangeland management (TRM) on perennial grass density and production, cattle performance, and wildlife habitat, while holding the annual stocking rate the same in …


Water Use Efficiency And Land Cover Variability On A Native Grassland Ranch On The Pampa Biome Of Uruguay, Diana L. Restrepo-Osorio, Gabriel De Oliveira, James Coll, Daniela Schossler Oct 2021

Water Use Efficiency And Land Cover Variability On A Native Grassland Ranch On The Pampa Biome Of Uruguay, Diana L. Restrepo-Osorio, Gabriel De Oliveira, James Coll, Daniela Schossler

IGC Proceedings (1977-2023)

Global efforts towards sustainable cattle ranching should be based on comprehensive approaches, targeting physical variables of the ranching process, as well as, the socioeconomic dimensions. Alianza del Pastizal is a non-profit conservation organization that works to preserve the temperate grasslands of the Southern Cone of South America by promoting conservation practices among ranching communities in Uruguay, Paraguay, Argentina, and Brazil. Alianza has become a mediator for ranchers exchanging information, resources, and education. Ranchers associated with the Alliance take pride in their property management as they aim to improve the community wellbeing and natural resource sustainability. In a previous study, producers …


Revisiting The Concept Of The Planning Region In Settings With Dynamic Spatial-Temporal Conditions: Lessons From Land Use Planning In Pastoral Areas Of Kenya, Ethiopia And Tanzania, H. Musoga, L. W. Robinson Oct 2021

Revisiting The Concept Of The Planning Region In Settings With Dynamic Spatial-Temporal Conditions: Lessons From Land Use Planning In Pastoral Areas Of Kenya, Ethiopia And Tanzania, H. Musoga, L. W. Robinson

IGC Proceedings (1977-2023)

Pastoralist rangeland systems often provide prime examples of scale mismatch—the challenge that arises when the scale and geographic extent of decision-making institutions do not correspond to the scale and geographic extent of problems that need to be addressed. Pastoralist resource use and traditional governance systems operate at multiple levels, and are often characterized by multiple, overlapping claims, rights, and management territories. Scholarship on pastoralist systems suggests that their fuzziness, flexibility, and overlap in territories and rights mean that there is no single scale or level that is optimal for effective resource governance. These characteristics stymie attempts to implement conventional …


Ewe Daily-Weight Gain Grazing Leucaena Leucocephala-Megathyrsus Maximus Cv Mombasa Silvopastoral System And Tropical Native Unimproved Range, L. K. Trejo-Arista, Enrique Cortés-Díaz, P. A. Martínez-Hernández, J. A. Cadena-Meneses Oct 2021

Ewe Daily-Weight Gain Grazing Leucaena Leucocephala-Megathyrsus Maximus Cv Mombasa Silvopastoral System And Tropical Native Unimproved Range, L. K. Trejo-Arista, Enrique Cortés-Díaz, P. A. Martínez-Hernández, J. A. Cadena-Meneses

IGC Proceedings (1977-2023)

Silvopastoral systems are a viable option to increase livestock productivity, The silvopastoral arrangement of Leucaena leucocephala associated with Megathyrsus maximus CV Mombasa (LMS) is successfully cultivated in tropical environments.. The objective of the study was to determine ewe daily-weight gain grazing LMS and a tropical unimproved native range. Two LMS were tested: high and low leucaena densities, 4700 and 2383 plants/ha, respectively. Grazing was rotational, lasted 150 d (rainy season) at equivalent stocking rate of 59 ewes/ha/150 d. Experimental design was a completely random design with three replications, the experimental unit was a 192 m2 plot. Variables measured on …


Status, Management, And Governance Of The Communal Grasslands Of Ethiopia’S Highlands: A Disappearing Asset For Mixed Crop-Livestock Livelihood Systems, Bedasa Eba, Fiona Flintan, Tesfa Getachew, Jason Sircely Oct 2021

Status, Management, And Governance Of The Communal Grasslands Of Ethiopia’S Highlands: A Disappearing Asset For Mixed Crop-Livestock Livelihood Systems, Bedasa Eba, Fiona Flintan, Tesfa Getachew, Jason Sircely

IGC Proceedings (1977-2023)

There is little documentation about the status, management, and governance of the communal grasslands of Ethiopia’s highlands. However, research being carried out by ILRI (International Livestock Research Institute) in northern Shewa, Amhara region, is highlighting their importance as a critical resource for those farmers engaged in mixed crop-livestock livelihood systems across the highland areas. These grassland areas range from 2 to 200 hectares and can be used by up to four different villages or ‘kebele’ and providing on average 10-20% of livestock feed for local farmers. However, this important resource is rapidly disappearing with encroachment of farming and tree-planting with …


Mgrre_Pureoilscouttickets_Pinder_2_21127022210000, Mgrre Oct 2021

Mgrre_Pureoilscouttickets_Pinder_2_21127022210000, Mgrre

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No abstract provided.


Removal Of The Northern Paleo-Teton Range Along The Yellowstone Hotspot Track, J. Ryan Thigpen, Summer J. Brown, Autumn L. Helfrich, Rachel Hoar, Michael M. Mcglue, Edward W. Woolery, William R. Guenthner, Meredith L. Swallom, Spencer Dixon, Sean Gallen Oct 2021

Removal Of The Northern Paleo-Teton Range Along The Yellowstone Hotspot Track, J. Ryan Thigpen, Summer J. Brown, Autumn L. Helfrich, Rachel Hoar, Michael M. Mcglue, Edward W. Woolery, William R. Guenthner, Meredith L. Swallom, Spencer Dixon, Sean Gallen

Earth and Environmental Sciences Faculty Publications

Classically held mechanisms for removing mountain topography (e.g., erosion and gravitational collapse) require 10-100 Myr or more to completely remove tectonically generated relief. Here, we propose that mountain ranges can be completely and rapidly (< 2 Myr) removed by a migrating hotspot. In western North America, multiple mountain ranges, including the Teton Range, terminate at the boundary with the relatively low relief track of the Yellowstone hotspot. This abrupt transition leads to a previously untested hypothesis that preexisting mountainous topography along the track has been erased. We integrate thermochronologic data collected from the footwall of the Teton fault with flexural-kinematic modeling and length-displacement scaling to show that the paleo-Teton fault and associated Teton Range was much longer (min. original length 190-210 km) than the present topographic expression of the range front (~65 km) and extended across the modern-day Yellowstone hotspot track. These analyses also indicate that the majority of fault displacement (min. 11.4-12.6 km) and the associated footwall mountain range growth had accumulated prior to Yellowstone encroachment at ~2 Ma, leading us to interpret that eastward migration of the Yellowstone hotspot relative to stable North America led to removal of the paleo-Teton mountain topography via posteruptive collapse of the range following multiple supercaldera (VEI 8) eruptions from 2.0 Ma to 600 ka and/or an isostatic collapse response, similar to ranges north of the Snake River plain. While this extremely rapid removal of mountain ranges and adjoining basins is probably relatively infrequent in the geologic record, it has important implications for continental physiography and topography over very short time spans.


Effects Of Nitrate On Arsenic Mobilization During Aquifer Storage And Recovery, Hania Hawasli Oct 2021

Effects Of Nitrate On Arsenic Mobilization During Aquifer Storage And Recovery, Hania Hawasli

USF Tampa Graduate Theses and Dissertations

Aquifer storage and recovery technology is used to sustain water resources and to prevent saltwater intrusion. The injected water can come from various resources, including treated wastewater. In pilot ASR studies in the Tampa Bay region, researchers found high As concentrations in the recovered water from the oxidation of the arsenopyrite that is embedded in the aquifers. The presence of dissolved O2 in the injected water is a major factor in the arsenopyrite oxidation during ASR, however the effects of NO3- on the arsenopyrite has not been studied yet. This is an important knowledge gap because injected water may contain …


Slow Slip Events And The Earthquake Cycle, Nicholas K. Voss Oct 2021

Slow Slip Events And The Earthquake Cycle, Nicholas K. Voss

USF Tampa Graduate Theses and Dissertations

Slow Slip Events (SSEs) represent a new type of strain release along faults, which have onlybeen recognized as a global phenomena with the growth of precision space-borne geodetic techniques. These events represent an important part of the strain budget on faults, sometimes bounding the area of co-seismic release and perhaps limiting the amount of seismic energy release. SSEs have also been suggested to proceed large megathrust earthquakes including the great 2011 Tohoku and 2015 Iquique earthquakes. I document a series of SSE along the Nicoya Peninsula in Costa Rica. These events take place both before and after the 2012 M7.6 …