European Diatom Database-ALPE Mountain Lake Dataset

The ALPE diatom-pH calibration data-set consists of surface-sediment diatom
assemblages from 118 lakes and contains 530 taxa. The ALPE training set is from
high-altitude or high-latitude lakes in the Alps, Norway, Svalbard, Kola
Peninsula, UK, Slovenia, Slovakia, Poland, Portugal, and Spain. Gravity or
piston corers were used to collect surface-sediment samples of 0.25 or 0.5 cm
thickness, usually from the deepest point in each lake and a total of at least
500 valves were counted from each sample. A large number of possible sites in
existing calibration sets, plus new ALPE project sites, were first screened
carefully to select a set of lakes meeting the criteria of an alpine or remote
location and an undisturbed catchment. The resulting ALPE data set of 118 lakes
is derived from the whole or parts of 5 data-sets. These are 31 lakes from a
Central Alps data set (Marchetto & Schmidt, 1993), 28 lakes from a Pyrenean
data set (Garcia & Catalan, unpub.), 30 AL:PE 1 and AL:PE 2 lakes in various
countries, 9 lakes from a Norwegian diatom-pH data set (Birks, Boyle & Berge,
unpub.), and 20 Norwegian, Welsh, and Scottish lakes from the SWAP calibration
set (see above). These 118 lakes have an altitudinal range of 20 m (northern
Svalbard 79o40'N, 10o45'E) to 3050 m (mean = 1762 m median = 2091 m).

This is a composite dataset derived from the following original datasets: ALPI,
ALPS, ALPU, Bergen and SWAP. Please see metadata for these records.