Publication Date:
2018-06-28
Description:
Publication date: 15 September 2018 Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 505 Author(s): A.A. Vela-Pelaez, N. Torrescano-Valle, G.A. Islebe, J.F. Mas, H. Weissenberger Holocene fossil pollen samples ( n = 38) from Lake Silvituc in Mexico were analyzed with the analog technique using modern pollen samples ( n = 98) of the Yucatán Peninsula, Mexico. Calculated dissimilarity indices allow us to reconstruct the vegetation and to develop a precipitation record for the last 7900 years. The Middle Holocene shows a gradual increase of precipitation and a marked drop in reconstructed precipitation around 4200 BCE. During the Late Holocene two phases were identified: Phase I (2500 BCE – 1 CE) shows the greatest increase in precipitation with four peaks around 1200 BCE, 650 BCE, 200 BCE and 1 CE. Also a period of increased precipitation resulted for the period between 200 and 500 BCE. Periods of reduced precipitation were detected at 900–1100 BCE, 500–600 BCE and 100–190 BCE. Phase II (1–2000 CE) encompasses several strong dry events during the following periods: 150–300 CE, 750–900 CE, 1050–1180 CE, and 1530–1580 CE. A strong reduction of 32% in precipitation in the late Preclassic Period (100–300 CE) was detected. Non-analogs of Phase II are associated with periods of reduced precipitation and fall into time periods of extended droughts related to the Maya Late Classic and the Little Ice Age. A limiting factor on the use of analogs for tropical forests is that a combination of different analogs for the same fossil pollen signal exists. Interpretation under these circumstances requires good knowledge of the ecology of the taxa and a priori characterization of the modern samples.
Print ISSN:
0031-0182
Electronic ISSN:
1872-616X
Topics:
Geosciences
,
Physics
