Enhancement of surface-atmosphere fluxes by desert-fringe vegetation through reduction of surface albedo and of soil heat flux

Under the arid conditions prevailing at the end of the dry season in the western Negev/northern Sinai region, vegetation causes a sharp increase relative to bare soil in the daytime sensible heat flux from the surface to the atmosphere. Two mechanisms are involved: the increase in the surface absorptivity and a decrease in the surface heat flux. By increasing the sensible heat flux to the atmosphere through the albedo and the soil heat flux reductions, the desert-fringe vegetation increases the daytime convection and the growth of the planetary boundary layer. Removal of vegetation by overgrazing, by reducing the sensible heat flux, tends to reduce daytime convective precipitation, producing higher probabilities of drought conditions. This assessment of overgrazing is based on observations in the Sinai/Negev, where the soil albedo is high and where overgrazing produces an essential bare soil. Even if the assessment for the Sinai/Negev does not quantitatively apply throughout Africa, the current practice in many African countries of maintaining a large population of grazing animals, can contribute through the mesoscale mechanisms described to reduce daytime convective precipitation, perpetuating higher probabilities of drought. Time-of-day analysis of precipitation in Africa appears worthwhile, to better assess the role of the surface conditions in contributing to drought

Model construction for decision support systems for beef stations

Decision Support System (DSS)

EXTERNALITIES, RISK AND THE PRIVATE PROPERTY-OVERGRAZING PARADOX: THE CASE OF PRIVATE CATTLE FARMS IN NYABUSHOZI COUNTY, WESTERN UGANDA

Livestock Production/Industries,

Collective Action and Responses to Poor‐Quality Recycling in St. John’s

This paper discusses the lack of proper recycling programs in St John’s, NL and explains the relevance of collective action and rational choice theories in addressing the matter. The city has done a poor job of implementing proper recycling programs, and is one of only two provincial capitals that does not offer a government-funded curb‐side recycling program. While some private recycling programs do exist in the city, they are inefficient and thus viewed by the populace as a waste of time. As most people believe that their individual waste contributions will not make much difference to the overall state of the environment, waste continues to accumulate and negatively impact the environment, as well as the image and state of the city. Collective action theory, as discussed by Ostrom, offers several possible solutions, such as privatization of territory or discussion amongst the populace. Unfortunately, such solutions are impractical for this particular problem. The government must step in and impose a recycling “Leviathan” by implementing mandatory recycling and forcing citizens to recycle or be left with their own refuse. Only by making recycling a self-interested priority for the populace will St John’s be able to improve its waste management practices

FITCA-EMMC workshops on information exchange and training with rural communities on environment: Eastern Uganda. W1

Four workshops were held in four sub counties in the districts of Soroti, Tororo, Iganga and Kamuli. Five to seven villages were involved in each sub county. Participatory approach was used to gather the farmers' perception on four environmental themes; Forests and woodlands, wetlands and water, land and soils and livestock and wildlife. The main issues that have caused changes in each theme were: deforestation; cultivation of wetlands and drying up of swamps; land degradation and low productivity; livestock diseases and habitat destruction. 5 The communities related the changes to their effects on human livelihood and incidences of sleeping sickness and Nagana. Majority of these changes have had negative impacts on livelihood, thus making the communities poorer than before. Loss of habitat due to over exploitation of forests and cultivation of wetlands have affected tsetse ecolo gy and resulted in sleeping sickness and Nagana. The activities being undertaken by FITCA in reclaiming tsetse infested areas and making them available for agricultural activities are short term benefits whereas land degradation and the resultant cycle of poverty are the long term outcomes, unless steps are taken now to address the expected land use changes and the land carrying capacity. In this regard the initiative to encourage zero grazing and pasture development may help to address the problem of land degradation. The communities developed a suite of recommendations and indicators for each theme. It is important that follow up meetings be done to see the development of action plans at village level to implement these recommendations in order to arrest the downward spiral of the environment. Involvement of communities in monitoring, management and conservation is important in order to have a sustained conservation effort, as these communities are the ones bearing the full impacts of the changes that have taken place in the environment. (Résumé d’auteur

Estimating vegetation cover from high-resolution satellite data to assess grassland degradation in the Georgian Caucasus

In the Georgian Caucasus, unregulated grazing has damaged grassland vegetation cover and caused erosion. Methods for monitoring and control of affected territories are urgently needed. Focusing on the high-montane and subalpine grasslands of the upper Aragvi Valley, we sampled grassland for soil, rock, and vegetation cover to test the applicability of a site-specific remote-sensing approach to observing grassland degradation. We used random-forest regression to separately estimate vegetation cover from 2 vegetation indices, the Normalized Difference Vegetation Index (NDVI) and the Modified Soil Adjusted Vegetation Index (MSAVI2), derived from multispectral WorldView-2 data (1.8 m). The good model fit of R2 = 0.79 indicates the great potential of a remote-sensing approach for the observation of grassland cover. We used the modeled relationship to produce a vegetation cover map, which showed large areas of grassland degradation

The River Lyn SAP Final Plan

This is the River Lyn Salmon Action Plan Final document produced by the Environment Agency in 2003. This final Salmon Action Plan (SAP) for the River Lyn catchment has been produced after consideration of feedback from external consultation. It provides a list of the agreed issues and actions for the next five years to maintain and improve the River Lyn salmon stock. The actions presented within this Salmon Action Plan clarify the important issues and factors currently limiting the salmon stock on the river. The resolution of these issues should ensure that a sustainable salmon population will be maintained for future generations. An attempt has been made to cost these actions, identify possible sources of funding and to provide a timescale for action. This SAP aims also to promote long term collaboration between the Agency and other interested parties in managing the River Lyn salmon stock and fisheries