Salvador Oliver

Impact of Municipal Waste on Mediterranean Dry Environments

We studied the physical characteristics and the main chemical components found in sealed municipal landfills in semi‐arid environments. This research was focused primarily on the identification of the main limiting factors for establishment and growth of plants on landfill surfaces, and the comparison of these factors with other soils in the area. Such information may be applicable to the future use of landfill sites. Variance analysis of our soil data showed that significant differences existed for 20 of the 36 parameters analyzed. The percentage of bare soil was much higher in landfills. Fine sand, silt, apparent density, and structural instability were greater in landfill covers than in other types of habitats. Field capacity and wilting point were low, and soil permeability to water was very low in the landfill covers. Electrical conductivity and pH were clearly higher in these environments, while organic matter and total N were much lower. Chloride, sulfate, fluoride, and sodium content were higher i...

Soil factors and Fe content in wild herbaceous plants

We study the average and range Fe contents in wild plants from pastures located in West and Central Spain, and how its Fe content is affected by some environmental factors, specially the soil variables: lithology, clay, pH, organic matter, free CaCO3, exchangeable Ca, Mg, K and Al, available P, total N, water, climate, rainfall, temperature range and light intensity.

Response of wild subclovers to soil calcium in xeric and acid Spanish soils

We studied nutrition in 123 field populations of Trifolium subterraneum, var. subterraneum and var. brachycladum Gib. et Belli, with respect to calcium and aluminium tolerance in low-fertility soils in western Spain, most of them situated in semi-arid environments. The observation of the ecological profiles allowed us to know the differences about the autoecological behaviour of the species and the two varieties with respect to soil exchangeable calcium and aluminium and percent of soil calcium carbonate. The response of populations of the two varieties of Trifolium subterraneum L. to the increase of soil exchangeable calcium directly affects the content of Mn and Na. Besides, we found significant differences for Mg and Fe contents in the populations of var. brachycladum. Differences in intervarietal behaviour were mainly related to populations that grew on soils with low and high exchangeable calcium levels, while the differences were small or absent at intermediate levels. There was a clear intervarietal difference with respect to the mean values of Na and Ca in the plants. In soils with higher exchangeable calcium levels there were also differences between both varieties with respect to Mg and K plant content, and therefore for the divalent/monovalent ratio. Our study further showed that populations exposed to the same level of available nutrients in low-fertility soils have markedly different uptake capacities. The results confirm the existence of stress-tolerant populations growing in soils with exchangeable calcium levels lower than 3 meq. 100 g−1. The results obtained will help to clarify the use of nutrients by plant close taxa in stressful environments.