Grazing intensity and vegetation change

1994 ◽  
Vol 18 ◽  
pp. 23-29
Author(s):  
J. A. Milne
Keyword(s):  
Vegetation Change ◽  
Management Practices ◽  
Production Systems ◽  
Rapid Change ◽  
Grazing Intensity ◽  
Abundant Species ◽  
Rate Of Change ◽  
Large Herbivores ◽  
Current State ◽  
The Uk

AbstractChange in the semi-natural vegetation of the hills and uplands of the UK is a relatively slow process. Whilst exogenous influences, such as climate and air quality, can influence the rate of change, the principal means whereby more rapid change can occur is through the actions of man in managing such resources to meet a range of objectives. Burning and grazing by large herbivores are the two most important management practices adopted and their interaction is central to the maintenance of vegetation in its current state and to its direction of change. This paper reviews how vegetation change associated with grazing occurs, how it can be measured, what the critical levels of grazing are for the most abundant species and what the implications of grazing are for nutrient supply for animal production systems.

Decreasing water pressure cues ‘bailout’ in seaweed-associated crustaceans

2020 ◽  
Vol 653 ◽  
pp. 121-129
Author(s):  
RB Taylor ◽  
S Patke
Keyword(s):  
Water Pressure ◽  
Rapid Change ◽  
Brown Seaweed ◽  
Model System ◽  
Rate Of Change ◽  
Suitable Habitat ◽  
Changing Light ◽  
Surface Increase ◽  
Reduced Water ◽  
Transparent Chamber

Small mobile crustaceans are abundant on seaweeds. Many of these crustaceans rapidly abandon their host if it is detached from the seafloor and floats towards the surface, but the trigger for this ‘bailout’ behaviour is unknown. We tested 2 potential cues, i.e. rapid change in light and rapid change in water pressure, using >1 mm epifauna on the brown seaweed Carpophyllum plumosum as a model system. Bailout occurred in response to reduced water pressure, but not to changing light, as (1) bailout occurred at similar rates in light and dark, (2) bailout occurred on the seafloor when water pressure was reduced within a transparent chamber by the equivalent of ~0.5 m depth or more, and (3) little bailout occurred when water pressure was held constant within the chamber while seaweeds were raised to the surface. Increase in pressure (simulating sinking) did not induce bailout. The rate of bailout increased with increasing magnitude of pressure reduction but was not influenced greatly by the rate of change of pressure within the range tested (up to an equivalent of 0.4 m depth s-1). The use of pressure rather than light as a cue for bailout is consistent with the need for seaweed-associated crustaceans to rapidly abandon a detached host and relocate to suitable habitat during both day and night.

French and Spanish Queer Film

2016 ◽  
Author(s):  
Chris Perriam ◽  
Darren Waldron
Keyword(s):  
Focus Groups ◽  
Sense Of Community ◽  
National Identities ◽  
Audience Research ◽  
Large Sample ◽  
Current State ◽  
Trans People ◽  
Screening Questionnaires ◽  
On Line ◽  
The Uk

This book advances the current state of film audience research and of our knowledge of sexuality in transnational contexts, by analysing how French LGBTQ films are seen in Spain and Spanish ones in France, as well as how these films are seen in the UK. It studies films from various genres and examines their reception across four languages (Spanish, French, Catalan, English) and engages with participants across a range of digital and physical audience locations. A focus on LGBTQ festivals and on issues relating to LGBTQ experience in both countries allows for the consideration of issues such as ageing, sense of community and isolation, affiliation and investment, and the representation of issues affecting trans people. The book examines films that chronicle the local, national and sub-national identities while also addressing foreign audiences. It draws on a large sample of individual responses through post-screening questionnaires and focus groups as well as on the work of professional film critics and on-line commentators.

Nitrate Leaching to a Shallow Mid-Atlantic Coastal Plain Aquifer as Influenced by Conventional No-Till and Low-Input Sustainable Grain Production Systems

1993 ◽  
Vol 28 (3-5) ◽  
pp. 691-700 ◽  
Author(s):  
J. P. Craig ◽  
R. R. Weil
Keyword(s):  
Management Practices ◽  
Production Systems ◽  
Cropping Systems ◽  
Cropping System ◽  
Atlantic Coastal Plain ◽  
Grain Production ◽  
Nitrogen And Phosphorus ◽  
Mineral N ◽  
Low Input ◽  
No Till

In December, 1987, the states in the Chesapeake Bay region, along with the federal government, signed an agreement which called for a 40% reduction in nitrogen and phosphorus loadings to the Bay by the year 2000. To accomplish this goal, major reductions in nutrient loadings associated with agricultural management practices were deemed necessary. The objective of this study was to determine if reducing fertilizer inputs to the NT system would result in a reduction in nitrogen contamination of groundwater. In this study, groundwater, soil, and percolate samples were collected from two cropping systems. The first system was a conventional no-till (NT) grain production system with a two-year rotation of corn/winter wheat/double crop soybean. The second system, denoted low-input sustainable agriculture (LISA), produced the same crops using a winter legume and relay-cropped soybeans into standing wheat to reduce nitrogen and herbicide inputs. Nitrate-nitrogen concentrations in groundwater were significantly lower under the LISA system. Over 80% of the NT groundwater samples had NO3-N concentrations greater than 10 mgl-1, compared to only 4% for the LISA cropping system. Significantly lower soil mineral N to a depth of 180 cm was also observed. The NT soil had nearly twice as much mineral N present in the 90-180 cm portion than the LISA cropping system.

scholarly journals Legumes increase grassland productivity with no effect on nitrous oxide emissions

2019 ◽  
Vol 446 (1-2) ◽  
pp. 163-177 ◽  
Author(s):  
Arlete S. Barneze ◽  
Jeanette Whitaker ◽  
Niall P. McNamara ◽  
Nicholas J. Ostle
Keyword(s):  
Management Practices ◽  
Production Systems ◽  
N Uptake ◽  
Relative Proportion ◽  
Management Strategies ◽  
Ghg Emissions ◽  
Chemical Properties ◽  
Nitrous Oxide Emissions ◽  
Mineral N ◽  
Grassland Productivity

Abstract Aims Grasslands are important agricultural production systems, where ecosystem functioning is affected by land management practices. Grass-legume mixtures are commonly cultivated to increase grassland productivity while reducing the need for nitrogen (N) fertiliser. However, little is known about the effect of this increase in productivity on greenhouse gas (GHG) emissions in grass-legume mixtures. The aim of this study was to investigate interactions between the proportion of legumes in grass-legume mixtures and N-fertiliser addition on productivity and GHG emissions. We tested the hypotheses that an increase in the relative proportion of legumes would increase plant productivity and decrease GHG emissions, and the magnitude of these effects would be reduced by N-fertiliser addition. Methods This was tested in a controlled environment mesocosm experiment with one grass and one legume species grown in mixtures in different proportions, with or without N-fertiliser. The effects on N cycling processes were assessed by measurement of above- and below-ground biomass, shoot N uptake, soil physico-chemical properties and GHG emissions. Results Above-ground productivity and shoot N uptake were greater in legume-grass mixtures compared to grass or legume monocultures, in fertilised and unfertilised soils. However, we found no effect of legume proportion on N2O emissions, total soil N or mineral-N in fertilised or unfertilised soils. Conclusions This study shows that the inclusion of legumes in grass-legume mixtures positively affected productivity, however N cycle were in the short-term unaffected and mainly affected by nitrogen fertilisation. Legumes can be used in grassland management strategies to mitigate climate change by reducing crop demand for N-fertilisers.

scholarly journals Pollination Potential in Portugal: Leveraging an Ecosystem Service for Sustainable Agricultural Productivity

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 431
Author(s):  
Caroline Wentling ◽  
Felipe S. Campos ◽  
João David ◽  
Pedro Cabral
Keyword(s):  
Land Management ◽  
Management Practices ◽  
Production Systems ◽  
Local Level ◽  
Well Being ◽  
Food Sources ◽  
Pollination Services ◽  
Pollinator Abundance ◽  
Study Results ◽  
Administrative Boundary

As urbanization and agriculture increase worldwide, habitats and food sources for wild pollinators are often fragmented or destroyed. As wild pollinators contribute both resilience and variety to agricultural fields, it is desirable to implement land management practices that preserve their well-being and ability to contribute to food production systems. This study evaluates continental Portugal for its change in suitability to host bee’s pollinator species (Apis mellifera) from 1990 to 2018. It uses the InVEST crop pollination modeling tool and CORINE Land Cover, as well as parameterization to produce pollinator abundance and supply maps. These are generalized to municipality boundaries to provide actionable insights to farmers and policymakers and strengthen land management practices. It finds that the potential for pollination services is growing, with averages of both pollinator abundance and supply indices improving by 8.76% across the continental territory in 28 years. The study results are validated using another pollination index derived from a study that is based on expert opinion and field sampling in a sub-region of Portugal. This method of aggregation of model results and comparison of the percent difference by administrative boundary has the potential to better inform both policymakers and farmers about the pollination potential on a local level, as well as inspire interventions for future productivity.

scholarly journals 395 Impact of pig mortality on U.S. pig producers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 184-185
Author(s):  
Caleb M Shull
Keyword(s):  
Feed Efficiency ◽  
Management Practices ◽  
Production Systems ◽  
Research Priorities ◽  
Functional Approach ◽  
Production Cycle ◽  
Limiting Factor ◽  
Significant Challenge ◽  
The Relationship ◽  
Positive Step

Abstract Swine producers in the U.S. face a significant challenge. On top of the ever-changing market dynamics that lead to wide swings in profitability or loss, is an underlying issue of pig mortality that the industry must address. While significant improvements in total piglets born per litter have been achieved over the last 10 years, pig mortality has seen no improvement or has worsened (Figure 1). When expressed as a percentage of piglets born (excluding mummies), a total of 7.9% were recorded as stillborn and 13.4% died prior to weaning in 2019. Assuming a typical mortality range of 7–10% from weaning to harvest, a typical U.S. producer could expect to lose around 27–30% of all piglets born. In addition, the average producer had around 12% annual sow mortality (Figure 1). Litter size and post-weaning growth rate and feed efficiency will always factor heavily into research priorities due to the economic impact associated with those traits; however, the opportunity to drive value through reduction in pig losses across the production cycle is staggering. In defense of the industry, improving pig survival is not an easy task for a number of reasons. The sample size (i.e., number of pigs) required to do mortality research correctly is often a limiting factor for many production systems. Furthermore, a cross-functional approach is likely required to make significant improvements in mortality. Specifically, the relationship between genetics, health, and management practices warrant consideration. Recent collaboration across the industry to improve mortality is a positive step forward and this collaboration should continue moving forward.

Research on HRM Based on Knowledge System

2014 ◽  
Vol 687-691 ◽  
pp. 4894-4897
Author(s):  
Xin Zhao
Keyword(s):  
Resource Management ◽  
Human Resource Management ◽  
Human Resource ◽  
Human Resources Management ◽  
Rapid Change ◽  
Design Organization ◽  
Resources Management ◽  
Current State ◽  
System Requirements ◽  
Basic Ideas

We are in an era of rapid change and the gradual opening of changes push us to make a lot of new theories and thinking to deal with the problems faced very different from previous close, and open and at the same time so that we can think about making reference to external experience. In this case, how should the planning, design, organization and implementation of both compatible with the current state of the personnel system requirements for the current situation of reform, but also has certain forward-looking human resources management system, is currently engaged in human resource management for all staff challenge. Based on this, the era of knowledge from four aspects of human resource management and knowledge management integration were discussed and presented the basic ideas.

A Survey of Glyphosate-Resistant Waterhemp (Amaranthus rudis) in Missouri Soybean Fields and Prediction of Glyphosate Resistance in Future Waterhemp Populations Based on In-Field Observations and Management Practices

2013 ◽  
Vol 27 (4) ◽  
pp. 656-663 ◽  
Author(s):  
Kristin K. Rosenbaum ◽  
Kevin W. Bradley
Keyword(s):  
Crop Production ◽  
Management Practices ◽  
Production Systems ◽  
Glyphosate Resistance ◽  
Continuous Cropping ◽  
Field Observations ◽  
Weed Species ◽  
Herbicide Treatment ◽  
Amaranthus Rudis

A survey of soybean fields containing waterhemp infestations was conducted just prior to harvest in 2008 and 2009 to determine the frequency and distribution of glyphosate-resistant waterhemp in Missouri, and to determine if there are any in-field parameters that may serve as indicators of glyphosate resistance in this species in future crop production systems. Glyphosate resistance was confirmed in 99 out of 144, or 69%, of the total waterhemp populations sampled, which occurred in 41 counties of Missouri. Populations of glyphosate-resistant waterhemp were more likely to occur in fields with no other weed species present at the end of the season, continuous cropping of soybean, exclusive use of glyphosate for several consecutive seasons, and waterhemp plants showing obvious signs of surviving herbicide treatment compared to fields characterized with glyphosate-susceptible waterhemp. Therefore, it is suggested that these four site parameters, and certain combinations of these parameters, serve as predictors of glyphosate resistance in future waterhemp populations.

DIFFERENCES IN PERCEPTION OF CAUSES OF CAMEL CALF LOSSES BETWEEN PASTORALISTS AND SCIENTISTS

2003 ◽  
Vol 39 (4) ◽  
pp. 363-378 ◽  
Author(s):  
B. A. KAUFMANN
Keyword(s):  
Causes Of Death ◽  
Management Practices ◽  
Production Systems ◽  
Quantitative Information ◽  
Knowledge Systems ◽  
Complete Understanding ◽  
Underlying Causes ◽  
Calf Mortality ◽  
Management Changes ◽  
Calf Rearing

Management deficiencies on the part of the pastoralists were claimed to be one of the major causes of the high losses of camel (Camelus dromedarius) calves contributing to low productivity of camel herds. In the present study, calf deaths, and the causes thereof, were analysed in connection with pastoral calf management in order to assess possible relationships. Progeny history data on 1506 Rendille, 789 Gabra and 1206 Somali calves born between 1980 and 1995 provided quantitative information on losses and the underlying causes. Assessment of the causes of death, and analysis of related management practices, led to suggestions for management changes. In feedback seminars with pastoralists, however, it became apparent that these management changes would not be adopted because they contradicted the pastoralists' assumptions on the causes of calf mortality. The discussions revealed that differences between pastoralists' and scientists' perceptions determined different opinions on proper calf-rearing management practices. Combining different knowledge systems offers the possibility of a more complete understanding, which is required for the derivation of adoptable calf mortality-reducing interventions that are compatible with the knowledge and production systems of the pastoralists.

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