UPPER QUATERNARY VEGETATION DYNAMICS AND PALEOCLIMATOLOGY OF THE LA CHONTA BOG AREA (CORDILLERA-DE-TALAMANCA, COSTA-RICA)

被引:57
作者
HOOGHIEMSTRA, H
CLEEF, AM
NOLDUS, GW
KAPPELLE, M
机构
[1] Hugo de Vries-Laboratory, Department of Palynology and Palaeo/Actuo-ecology, Amsterdam, 1098 SM
关键词
PALYNOLOGY; VEGETATION DYNAMICS; QUATERNARY CLIMATIC CHANGE; YOUNGER DRYAS EVENT; COSTA-RICA;
D O I
10.1002/jqs.3390070303
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
Two pollen records from La Chonta bog (2310 m altitude) and one pollen record of a soil profile (2430 m altitude) at a short distance from the bog permit the reconstruction of the vegetational history and climatic sequence of probably the last ca. 80 000 yr of the Cordillera de Talamanca, Costa Rica. The three pollen records can be correlated on the basis of three radiocarbon-dated horizons (> 39 900 yr BP, 34 850 yr BP and 1390 yr BP) and palynostratigraphy. Pollen concentration data provide indirect time control between radiocarbon-dated horizons of the La Chonta 2 core. During the Early Glacial successive fluctuations of the upper forest line occurred between ca. 2300 m and 2800 m altitude and the bog is alternately situated close to the subalpine rainforest belt and in the uppermontane rainforest belt. During the Pleniglacial (ca. 50 000-13 000 yr BP) the forest line fell to ca. 2000 m altitude and paramo vegetation surrounded the La Chonta site. During the Late Glacial the forest line shifted rapidly in ca. 270 yr to 2700-2800 m altitude and the lake became surrounded by Quercus-dominated upper montane rainforest during a period of ca. 1655 yr. A distinct climate cooling (by 2-2.5-degrees-C) followed during ca. 580 yr and the upper forest line dropped to ca. 2400 m altitude. This temperature rebound is probably equivalent to the Younger Dryas event. In the depression extensive Alnus carr and swamp vegetation developed. Finally, during the Holocene, the forest line shifted to 3300-3500 m elevation and the lower montane rainforest reached close to ca. 2300 m altitude. In the later part of the Holocene subparamo scrub with Hypericum, Puya, Compositae, Escallonia and Ericaceae largely replaced Alnus carr and the regional and local vegetation closely resembles the present-day composition. During the Last Glacial to Holocene transition a shift of the upper forest line of ca. 1400 m is inferred, corresponding to a glacial temperature depression at 2300 m altitude of ca. 8-degrees-C.
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页码:205 / 225
页数:21
相关论文
共 59 条
[1]  
Acosta-Solis M., Los Paramos Andinas del Ecuador, (1984)
[2]  
Bartlett A.S., Barghoorn E.S., Phytogeographic history of the Isthmus of Panama during the past 12,000 years (a history of vegetation, climate, and sea‐level change). IN:, Vegetation and Vegetational History of Northern Latin America, a Symposium, pp. 203-299, (1973)
[3]  
Blaser J., Standörtlich und waldkundliche Analyse eines Eichen‐Wolkenwaldes (Quercus spp.) der Montanstufe in Costa Rica, Göttinger Beiträge zur Land‐ und Forstwirtschaft in den Tropen und Subtropen, 26, (1987)
[4]  
Bush M.B., Colinvaux P.A., A pollen record of a complete glacial cycle from lowland Panama, Journal of Vegetation Science, 1, pp. 105-118, (1990)
[5]  
Chaverri A., (1988)
[6]  
Chaverri A., Vaughan C., Poveda L., Informe de la gíra efectuada al macizo de Chirripó a raíz del fuego ocurrido en marzo de 1976, Revista de Costa Rica, 11, pp. 243-279, (1976)
[7]  
Cleef A.M., Characteristics of Neotropical paramo vegetation and its subantarctic relations, Geo‐ecological Relations Between the Southern Temperate Zone and the Tropical Mountains, pp. 365-390, (1978)
[8]  
Cleef A.M., (1981)
[9]  
Cleef A.M., Chaverri A.
[10]  
Cleef A.M., Rangel J., Vegetation of the paramos of the northwestern part of the Sierra Nevada de Santa Marta, Studies on Tropical Andean Ecosystems, Vol. 2, La Sierra Nevada de Santa Marta (Colombia), Transecto Buritaca La Cumbre, pp. 203-266, (1984)