Pollen record

Bonnefdle, R. 1995 A reassessment of the Plio-Pleistocene pollen record of East Africa. In Vrba, E.S., Denton, G.H., Partridge, T.C. andBurckle, L.H., eds., Paleoclimate and Evolution. New Haven, CT, Yale University Press 299-310. 

The Holocene spans the past 11,500 years. Much of the Holocene time scale is obtained from Greenland and Antarctic ice-core data, from stratigraphic pollen records, and other records of floral, faunal, and landscape changes. Records younger then 45,000 years are also within the range of radiocarbon dating. The recent Holocene is the historic period when some written records are available and finally the past century or so, the contemporary period, where directly measured climatic data are available for comparison. 

Similar observations in Red Spider Cave, northwest Georgia, provided a good pollen record over the past 40,000 years, thus allowing interpretation of the local climate through the last glaciation in an area well south of the glacier margins (Brook and Nickmann, 1996). 

From the assemblages of fossil pollen, palynologists make inferences about the types of forests or other plant communities that may have occurred in the local environment. These interpretations must be made carefully, however, because species are not represented in the pollen record in ways that directly reflect their abundance as mature plants. For example, pollen of wind-pollinated species is relatively abundant in lake sediments, whereas species that are insect pollinated are not well... 

Palynology is the study of fossil pollen (and sometimes plant spores) extracted from lake sediment, peat bog, or other matrices. The most common goal of paly-nological research is to reconstruct the probable character of historical plant communities, inferred from the abundance of species in dated portions of the fossil pollen record. Pollen analysis is an extremely useful tool for understanding the character of ancient vegetation and its response to changes in environmental conditions, particularly in climate. Pollen analysis also has an economically important modem industrial use in the exploration for resources of fossil fnels. Palynology is also used to help reconstmct the probable habitats and foods of ancient humans and of wild animals. 

Van t Veer, R., Hooghiemstra, H. 2000. Montane forest evolution during the last 650.000 yr in Colombia a multivariate approach based on pollen record Funza-I. J. Quaternary Sci. 15 329-346. 

Perhaps the best known of the mass extinctions is that associated with the demise of the dinosaurs at the Cretaceous—Tertiary boundary, which has been attributed to a meteorite impact (Alvarez et al. 1980 Kruge et al. 1994 Skelton et al. 2003), although natural climate change may also have been a factor. Planktonic organisms (particularly foraminiferans, calcareous phytoplankton and radiolarians) were also severely affected. On land, trees seem to have been devastated, with the recovery period marked by the proliferation of ferns. The pollen record is dominated by fern spores, and hence known as the fern spike, which is observed... 

Such molecular studies offer some advantages over the pollen record when reconstructing local climate, because pollen distributions are strongly influenced by ae-olian transport and the amount of pollen produced by different species, whereas leaf and wood components are more likely to be deposited in situ (although some aquatic transport is possible). 

FIGURE 3 Maps showing distances between outlying colonies and the main population at the time the colonies were established, as indicated by the fossil pollen records of beech (a) and hemlock (b) (S. Webb, 1987 Woods and Davis, 1989 Davis et al., 1986 Calcote, 1986 Davis et al, unpublished data). 

Davis, M. B. and Botkin, D. B. 1985. Sensitivity of cool-temperate forests and their fossil pollen record to rapid temperature change. Q. Res. 23, 327-340. 

Rommerskirchen, F., Eglinton, G, Dupont, L., Guntner, U., Wenzel, C. and Rullkotter, J., 2003. A north to south transect of Holocene Southeast Atlantic continental margin sediments Relationship between aerosol transport and compound-specific 5 C land plant biomarker and pollen records. Geochem. Geophys. Geosyst., 4 (12), 1101, DOI 10.1029/2003GC000541. 

The science of reconstructing the past flora and past climate from pollen data obtained from lake and bog sediments. The fossil pollen record is a function of the regional flora and vegetation at a given time and location, particulate matter... 

Muller, J. (1981). Fossil pollen records of extant angiosperms. Botanical Review, 47,1-142. 

Pollen records only skirt the borders of the Cerrado Biome (see Mayle, Chapter 17, Figure 17.1), making inference of the Quaternary history of this area difficult. The most relevant sites are at the edges of the southern cerrados, and are reviewed by both Mayle (Chapter 17) and Durigan (Chapter 3). They show a complex shifting over the past 30,(X)0-40,000 years of cerrado, SDTF... 

Historical population migration at the rain forest-savanna boundary could also be addressed with molecular population genetics, although, in this case, studies should focus on rain forest species that are hypothesized to have recently expanded their distributions. If demographic expansion of rain forest species at the rain forest-savanna ecotone in areas such as Bolivia has been as rapid as the fossil pollen record implies (Mayle et al., 2000 Mayle, Chapter 17), then... 

Colinvaux, P.A. et al., A long pollen record from lowland Amazonia forest and cooling in glacial times. Science, 21 A, 85, 1996. 

Behling, H., A high resolution Holocene pollen record from Lago do Pires, SE Brazil vegetation, climate and fire history, J. PaleolimnoL, 14, 253, 1995. 

The aim of this chapter, which expands upon Mayle (2004), is to review previously published palaeo-ecological data (predominantly fossil pollen records) from the South American tropics to determine how SDTF have responded to Late Quaternary enviromnental changes, and thereby better understand the development of the current disjunct pattern of dry forest distributions, and the floristic links between them. In particular, the validity of the dry forest refugia hypothesis, proposed by Prado and Gibbs (1993) and Pennington et al. (2000) will be examined. 

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