Life Sciences Commons^™

Grassland In Ireland And The Uk, Myles Rath, S. Peel

IGC Proceedings (1997-2023)

1. Grassland is the dominant land use option in Ireland and the UK, and is characterised by a long growing season.
2. Dynamic, interactive systems of grassland management have been developed which combine high grass dry matter intakes with good sward quality. In the better grassland areas milk yields in excess of 7000 kg/cow are attainable with low levels of concentrate supplementation. In the times to come, measures to protect the environment will constrain stocking rates, and fertiliser and manure use on intensive grassland enterprises.
3. A high proportion of beef and sheep farms participate in voluntary, EU-funded agri- environmental schemes that promote …

How Herbivores Optimise Diet Quality And Intake In Heterogeneous Pastures, And The Consequences For Vegetation Dynamics, R. Baumont, Cécile Ginane, F. Garcia, P. Carrère

IGC Proceedings (1997-2023)

Understanding the interplay between foraging behaviour and vegetation dynamics in heterogeneous pasture is an essential requirement for evaluating the value of the resource for large herbivores and for managing that resource. The orientation of selective grazing behaviour between intake and diet quality depends on the spatial and temporal scales considered. In the short-term scale of a grazing sequence, there is evidence that large herbivores tend to optimise the intake rate of digestible materials by adaptation of their biting behaviour and by patch choice. On a day-to-day scale, there is evidence that large herbivores tend to prioritise the quality of the …

Land Use History And The Build-Up And Decline Of Species Richness In Scandinavian Semi-Natural Grasslands, O. Eriksson, S. A. O. Cousins, R. Lindborg

IGC Proceedings (1997-2023)

Scandinavian semi-natural grasslands have an exceptionally high small-scale species richness. In the past, these grasslands covered extensive areas but they have declined drastically during the last century. How species richness of semi-natural grasslands was built up during history, and how species respond to land use change, are discussed. The agricultural expansion from the late Iron Age was associated with increasing grassland extent and spatial predictability, resulting in accumulation of species at small spatial scales. Although few species directly depend on management, the specific composition of these grasslands is a product of haymaking and grazing. Grassland fragmentation initially has small effects …

Recreating Pastoralist Futures, T. J. P. Lynam

IGC Proceedings (1997-2023)

Research experience in southern Africa is used to reflect on key determinants of pastoral futures and how they might need to be addressed. The paper begins with a brief review of what we mean by marginality. A set of observations on key issues defining the option sets for pastoralism in the future is then presented. The first of these is that only a small number of structures or processes actually control the behaviour of social-ecological systems such as pastoralist systems. A second observation is that the future is so uncertain that there is a need to learn to design for …

Working Within Constraints: Managing African Savannas For Animal Production And Biodiversity, J. T. Du Toit

IGC Proceedings (1997-2023)

The mean density of livestock biomass on African rangelands now greatly exceeds that of indigenous large herbivores, although livestock cannot fully substitute for wildlife with respect to co-evolved ecosystem processes involving herbivory. The dominance of livestock in semi-arid rangelands is largely due to water provision, which uncouples livestock population dynamics from the rainfall-driven trajectories followed by indigenous ungulate species in wildlife areas. Ecological sustainability cannot be achieved with a few exotic species maintained at unprecedented biomass densities in savanna ecosystems, which are evolutionarily adapted for species-rich communities of ungulates of a wise range of sizes. Integrating wildlife and livestock in …

Challenges And Opportunities For Sustainable Rangeland Pastoral Systems In The Edwards Plateau Of Texas, J. W. Walker, J. L. Johnson, C. A. Taylor Jr.

IGC Proceedings (1997-2023)

This paper focuses on pastoral systems in an area of west-central Texas known as the Edwards Plateau. These rangelands have a combination of grass, forb and browse species and are used primarily for combinations of grazing by cattle, sheep, goats and wildlife. A major ecological challenge is woody plant encroachment. Stocking rate is the major factor affecting sustainability and historically this area was heavily grazed. Today the stocking rate is half or less of its historical peak. Species of livestock has shifted from predominantly small ruminant to cattle. About 70 % of pastoralists use some sort of rotational grazing system. …

Diversity And Variation In Nutritive Value Of Plants Growing On 2 Saline Sites In Southwestern Australia, H. C. Norman, R. A. Dynes, D. G. Masters

IGC Proceedings (1997-2023)

In south-western Australia 10% or 1.8 million ha of the farmed area is affected by dryland salinity and a further 6 million ha are at risk of salinity (NLWRA, 2001). Animal production from saltbush (Atriplex spp.)-based pasture systems represents the most likely large-scale opportunity for productive use of saline land in the short to medium term. Feeding saltbush-based pastures as a maintenance feed during the prolonged autumn feed gap typical in Mediterranean-type climates maximises their economic value. The aim of this study was to explore the diversity and nutritive value of plants that typically persist in saltbush-based saltland pastures.

The Long Road To Developing Native Herbaceous Summer Forage Legume Ecotypes, J. P. Muir, T. J. Butler, W. R. Ocumpaugh

IGC Proceedings (1997-2023)

Only a handful of well-adapted herbaceous summer forage legumes are currently marketed for drier regions of North America and even fewer are true natives. There is a growing demand for native germplasm in the region as a new generation of landowner attempts to return grasslands to a semblance of their original species and diversity. The objective of this paper is to describe preliminary research results of a grasslands team collecting, studying and promulgating native leguminous germplasm in Texas.

Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller

IGC Proceedings (1997-2023)

No abstract provided.

Selecting Grassland Species For Saline Environments, M. E. Rogers, A. D. Craig, T. D. Colmer, R. Munns, S. J. Hughes, P. M. Evans, P. G. H. Nichols, R. Snowball, D. Henry, J. Deretic, B. Dear, M. Ewing

IGC Proceedings (1997-2023)

In Australia, around 5.7 million hectares of agricultural land are currently affected by dryland salinity or at risk from shallow water tables and this figure is expected to increase over the next 50 years (LWRA, 2001). Most improved grassland species cannot tolerate the combined effects of salt and waterlogging and, therefore, the productivity of sown grasslands in salt-affected areas is low. However, there is potential to overcome the lack of suitably adapted fodder species by introducing new, salt and waterlogging-tolerant species and by diversifying the gene pool of proven species. Potential species include exotic, naturalised and native Australian grass, legumes, …

Grazing Animal Production Systems And Grazing Land Characteristics In A Semi-Arid Region Of Greece, I. Hadjigeorgiou, G. Economou, D. Lolis, N. Moustakas, G. Zervas

IGC Proceedings (1997-2023)

Rough grazing in Greece cover about 40% of the total land area, is publicly owned and managed extensively (Hadjigeorgiou et al., 2002). The Prefecture of Larisa is in the centre of Greece, and has 212,000 ha of rough grazing land, with a variable topography ranging from sea level up to 3,000 m a.s.l. This area is utilized by a total population of 135,000 LU (mainly sheep, goats and some suckler cows), which consumes annually an appreciable fraction of their total nutrient requirements from rough grazing.

The Productivity Of Coastal Meadows In Finland, R. Nevalainen, S. Jaakola, A. Huuskonen, J. Kiljala, E. Joki-Tokola

IGC Proceedings (1997-2023)

The coastal meadows of Finland have gained a new interest as a summer pasture for cattle. These habitats have great historical, aesthetic and biological value (Pessa & Anttila, 2000). Typical features of the coastal meadows are the varying vegetation zones and wet, sometimes waterlogged, soils. The meadows are important nesting and feeding habitats for many water birds. When grazing ceases, reeds, trees and shrubs take over and the area loses its openness. Lately the amount of grasslands and pastures has drastically declined all over Europe. In Finland, the area of semi-natural biotopes has decreased to 1% of what it had …

Grass And Forage Plant Improvement In The Tropics And Sub-Tropics, Liana Jank, C. B. Do Valle, Rosangela M. S. Resende

IGC Proceedings (1997-2023)

1. The majority of tropical and subtropical forage grass genera and/or species have not yet been collected, or need further collection to be representative of their natural distribution.
2. New biotechnological techniques will only result in the release of superior forage cultivars if supported by strong breeding programs.
3. More funding and investment in the formation of strong public research teams in forage conservation and improvement are needed to guarantee the sustainability of tropical and subtropical pasture-based livestock systems in the future.
4. The creation of a permanent international working group on tropical and subtropical forages is essential to assist the International Plant Genetic …

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

Data Curation For Modeling Tall Fescue Biomass Dynamics With Dssat-Csm, M. B. Hanson, P. D. Alderman, T. J. Butler, A. Caldeira Rocateli

IGC Proceedings (1997-2023)

While models for predicting forage production are available to aid management decisions for some forage crops, there is limited research for a yield model designed specifically for tall fescue (Schedonorus arundinaceus). Therefore, our objective was to adapt an existing perennial forage model, the Decision Support System for Agrotechnology Transfer Cropping Systems Model (DSSAT-CSM) for predicting forage biomass of tall fescue in the southern Great Plains. To evaluate model performance, there must first be a high level of data manipulation and cleaning. In this project, a cohesive dataset combining biomass, weather, soil, and management data were structured into DSSAT …

Opportunities And Challenges In Augmenting Honey Bee Forage Resources With Pasture Legumes In Southern Australia, M. Kratz, M. Brown, M. T. Newell, R. C. Hayes

IGC Proceedings (1997-2023)

More than 80% of Australian honey is produced from native tree and shrub species. However, with increasing demands on public lands along with production risks posed by drought, floods and wildfires, there is a need to identify alternative forage resources to augment Australian honey production. With over 30 pasture legumes now available for agriculture in southern Australia, opportunity exists to increase the utilisation of some species with co-benefits to multiple production industries. However, there is little understanding of the potential value of most pasture legumes for honey production, and side by side comparisons are complicated by factors such as differences …

Can Changing Breeding Structure Serve As A Climate Adaptation Strategy? Evidence From A Comparative Study Of China And Mongolia, Y. Zhang, Z. Huang, J. Wang, Y. Huang, T. Hao, G. Xu

IGC Proceedings (1997-2023)

Under the influence of climate change, the vulnerability of grassland ecosystems in the Mongolian Plateau has increased. Correspondingly, herdsmen need to adopt more livelihood adaptation strategies to cope with changes in climate and grassland environment. The purpose of this study is to analyze the impact of breeding structure on grassland quality in Mongolian plateau. We select 20 border provinces/banners of Mongolia and Inner Mongolia Autonomous Region for research, and combined statistical data with remote sensing data of 2007-2016. The Normalized Difference Vegetation Index (NDVI) is used to quantify the grassland vegetation quality. Results show that there are differences in livestock …

Development And Biological Evaluation Of Selective Small-Molecule Inhibitors Of The Human Cytochrome P450 1b1, Austin Hachey

Theses and Dissertations--Chemistry

The human cytochrome P450 1B1 (CYP1B1) is an emerging target for small- molecule therapeutics. Several solid tumors overexpress CYP1B1 to the degree that it has been referred to as a universal tumor antigen. Conversely, its expression is low in healthy tissues. CYP1B1 may drive tumorigenesis through promoting the formation of reactive toxins from environmental pollutants or from endogenous hormone substrates. Additionally, the expression of CYP1B1 in tumors is associated with resistance to several common chemotherapies and with poor prognoses in cancer patients. However, inhibiting CYP1B1 with small molecules has been demonstrated in cellular and murine model systems to reverse this …