Ga. Islebe et H. Hooghiemstra, VEGETATION AND CLIMATE HISTORY OF MONTANE COSTA-RICA SINCE THE LAST GLACIAL, Quaternary science reviews, 16(6), 1997, pp. 589-604
New palynological evidence from the Cordillera de Talamanca (Costa Ric
a) is presented. The La Chonta-1 core (2310 m a.s.l) shows the develop
ment of montane vegetation during the late Quaternary. A shorter core
(La Trinidad-III) shows the Lateslacial-Holocene transition, including
the La Chonta stadial based on earlier published evidence, A soil sec
tion from the paramo belt at 3100 m shows vegetation recovery after fi
re. Modern pollen rain was studied along an altitudinal transect from
2100 m to 3800 m at Mt Chirripo. A comparison with other palaeoecologi
cal data of the region is given to elucidate climatic and vegetational
changes throughout the Central American region. Data show a cooling o
f 7-8 degrees C during the Last Glacial Maximum (LGM) for montane Cost
a Pica, which is in accordance with data from lowland Guatemala. A 1.5
degrees to 2.5 degrees C temperature drop is recorded during the Youn
ger Dryas Chron in both Costa Pica and Guatemala, but apparently not i
n Panama. The Lateglacial-Holocene transition in montane Costa Rica is
established at 10,400 BP. Between 9000 and 8500 BP moist forest devel
oped in mountainous Costa Pica as well as in lowland Guatemala and Pan
ama. Environmental change during the mid-Holocene seems more affected
by changes in humidity than temperature change throughout Central Amer
ica. Distribution maps of paramo and montane vegetation in Costa Rica
are reconstructed for 10 ka, 14 ka and 18 ka based on currently availa
ble palynological data. These data indicate that during the LGM a para
mo vegetation corridor existed between northern Costa Pica and probabl
y northern Panama. (C) 1997 Elsevier Science Ltd.