European Diatom Database-Spanish Saline Lake Dataset

The European Diatom Database (EDDI) is a web-based information system designed
to enhance the application of diatom analysis to problems of surface water
acidification, eutrophication and climate change.

The Spanish training set includes 74 samples from 57 sites situated between
42N and 36S in latitude, 6W and 2E in longitude. Sampling was restricted to
endorheic zones of flat topography, from the interior plateau: La Mancha and
Albacete (central Spain) and Zamora (northeastern Spain), and from the lowlands
of Andaluc?a (southern Spain) and the Ebro basin (northeastern Spain), at
altitudes ranging from 2-1020m asl. Conductivity ranges from 150 to 338,000 ?S
cm-1. There is a tendency for water chemistry to be dominated by sulphates in
the central plateau region, chlorides in Andaluca, and mixed chloride- or
sulphate-dominance in the Ebro basin, dependent on the mineralogy of underlying
Tertiary or Triassic marine or continental evaporites. Carbonate-dominated
waters are rare, comprising a small number of freshwater, karstic systems.
Samples were collected by J. Reed during her PhD (UCL Geography). Following
removal of four outliers from the training set, a conductivity transfer
function (r2 = 0.91) was derived for Spanish salt lakes (Reed 1995, 1998),
which has been applied to one Spanish sequence (Reed 1995, Reed in press, Reed
et al., 2001) and in unpublished work in Mexico. Based mainly on the above
combined African transfer function, optima from the Spanish transfer function
were also used in conductivity reconstruction for sites in Turkey (Reed et al.
1999, Roberts et al. 2001).