Modelling the influence of peri-urban trees in the air quality of Madrid region (Spain)

Tropospheric ozone (O(3)) is considered one of the most important air pollutants affecting human health. The role of peri-urban vegetation in modifying O(3) concentrations has been analyzed in the Madrid region (Spain) using the V200603par-rc1 version of the CHIMERE air quality model. The 3.7 version of the MM5 meteorological model was used to provide meteorological input data to the CHIMERE. The emissions were derived from the EMEP database for 2003. Land use data and the stomatal conductance model included in CHIMERE were modified according to the latest information available for the study area. Two cases were considered for the period April-September 2003: (1) actual land use and (2) a fictitious scenario where El Pardo peri-urban forest was converted to bare-soil. The results show that El Pardo forest constitutes a sink of O(3) since removing this green area increased O(3) levels over the modified area and over down-wind surrounding areas.     

Simulation of stomatal conductance for Aleppo pine to estimate its ozone uptake

The data from a previous experiment carried out in open-top chambers to assess the effects of ozone (O3) exposure on growth and physiology of Aleppo pine (Pinus halepensis Mill.) were re-assessed to test the performance of the EMEP O3 stomatal conductance model used to estimate tree O3 uptake at a European scale. Aleppo pine seedlings were exposed during three consecutive years to three different O3 treatments: charcoal filtered air, non-filtered air and non-filtered air supplemented with 40 nl l(-1). The results of the model using the default parameterisation already published for Mediterranean conifers showed a poor performance when compared to measured data. Therefore, modifications of g(max), f(min), and new f(VPD), f(temp) and f(phen) functions were developed according to the observed data. This re-parameterisation resulted in a significant improvement of the performance of the model when compared to its original version.     

Evaluation of fruit-vegetable and fish wastes as alternative feedstuffs in pig diets

Fruit-vegetable and fish wastes were evaluated as potential feedstuffs for growing-finishing pigs. Wastes were collected from shops in the city of Salamanca (Spain) and their nutritional composition, mineral content and digestibility were determined. The dry matter of the wastes under study was relatively low (12% for fruit-vegetable waste and 26% for fish waste), but they presented all of the nutrient requirements for swine diets. The fish waste contained 58% crude protein, 22% ash, 19% ether extract and 1% crude fibre, whereas the fruit-vegetable waste contained 65% nitrogen free extract, 13% crude fibre, 12% crude protein, 8% ash and 2% ether extract. Waste digestibility decreased with temperature, and hence temperatures over 65 degrees C for fruit-vegetable waste and 105 degrees C for fish waste should not be used in the treatment to reduce the moisture and to ensure the microbiology quality. Therefore, two diets were formulated using linear programming. The analysed waste was included in approximately 20% of one of the diets, while another diet was formulated without any type of waste. These data showed that this part of biodegradable municipal waste could be managed as alternative feedstuffs in swine diets, reducing the amount of biodegradable municipal waste going to landfills.