Data comprise stable element concentrations in terrestrial Reference Animals and Plants (RAPs) and corresponding whole-body concentration ratios determined in two different Mediterranean ecosystems: a Pinewood and a Dehesa (grassland with disperse tree cover). The International Commission on Radiological Protection (ICRP) RAPs considered in the Pinewood ecosystem were Pine Tree and Wild Grass; whereas in the Dehesa ecosystem those considered were Deer, Rat, Earthworm, Bee, Frog, Duck and Wild Grass. The data include: elemental concentrations in soils; elemental concentrations in plants, invertebrates, vertebrate tissues and estimated concentrations for vertebrate whole-organisms; individual concentration ratios (relating the fresh matter concentration in organisms to the dry matter concentration in soil); vertebrate species tissue masses; fresh to dry matter data for invertebrate species; geometric and arithmetic mean and standard deviation summaries for elemental concentrations and concentration ratios. Elemental concentrations presented include I, Li, Be, B, Na, Mg, Al, P, S, K. Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Cs, Ba, Tl, Pb and U. radioecology