Environmental impacts of Little Ice Age cooling in central Mexico recorded in the sediments of a tropical alpine lake

Environmental changes during the last millennium recorded in subfossil Cladocera, diatoms and sediment geochemistry from Lake El Sol (Central Mexico)

“…Alona manueli in hab its the lit to ral zone and lives in as so ci a tion with plants on sandy sed i ment. As sug gested by pre vi ous stud ies (Zawisza et al, 2012;Sinev and Zawisza, 2013;Cuna et al, 2014), both en demic spe cies pre fer ben thic hab i tats and are tol er ant to low nu tri ent con cen tra tions and low pH val ues. However, the ecol ogy of these spe cies is still not well-known.…”

“…in a small catch ment area, there fore we ex pect that these re sults should pro vide a "clear" eco log i cal and cli ma tic sig nal as high-al ti tude lakes are usu ally not af fected by com plex soil and veg e ta tive re sponses to hu man ac tiv i ties in their catch ments (Cuna et al, 2014).…”

“…Those min er als are usu ally trans ported into the lake from the catch ment by pre cip i ta tion and sur face runoff. Due to the char ac ter is tics of the catchment and ba sin of this lake (poorly de veloped veg e ta tion and soils), the mag netic sus cep ti bil ity can be di rectly re lated to precip i ta tion (Cuna et al, 2014).…”

“…How ever so far, palaeolimnological and palaeo eco logi cal anal y ses us ing subfossil Cladocera, have been mainly con ducted at high lat i tudes (Eu rope, Rus sia, Can ada, and north ern parts of the USA). Only a few stud ies on subfossil cladoceran fauna have been conducted in the south ern hemi sphere (e.g., Brazil, Chile, Uru guay, and New Zea land; Serafim et al, 2003;Iglesias et al, 2007;Coronel et al, 2007;Kotov et al, 2010;Kattel, 2010) and there is only one re cord from trop i cal North Amer ica (Mex ico) (Zawisza et al, 2012;Cuna et al, 2014).…”

“…In these eco sys tems, even very small dif fer ences in tem per a ture be tween warm and cold pe ri ods can strongly af fect wa ter level, wa ter chem is try, the length of the grow ing sea son, and the com po si tion of aquatic plant and an i mal pop u la tions (Koining et al, 2002;Cuna et al, 2014). Ad di tion ally, high-al ti tude lakes are of ten con sid ered to be pris tine, which makes them suit able ob jects for study ing past cli ma tic and en vi ron men tal changes (McCormack et al, 2009;Cuna et al, 2014). In ad di tion the de pos its of high-al ti tude lakes con tain bio-in di ca tor re mains that re flect en vi ron men tal changes, spe cif i cally the re mains of Cladocera (Hofmann, 2000;Kamenik et al, 2007) and di a toms (Battarbee et al, 2002).…”