Review: Amazon Pollen Manual and Atlas/Manual E Atlas Palinologico Da Amozonia

Article excerpt

Review: Amazon Pollen Manual and Atlas/Manual e Atlas Palinologico da Amozonia By Paul Colinvaux, Paulo Eduardo de Oliveira, and Jorge Enrique Moreno Patiño Reviewed by Susanne Renner University of Missouri-St. Louis, USA Paul Colinvaux, Paulo Eduardo de Oliveira, and Jorge Enrique Moreno Patiño. Amazon Pollen Manual and Atlas/Manual e Atlas Palinologico da Amozonia. Amsterdam: Harwood Academic Publishers, 1999. 322 pp. ISBN 90-5702- 587-6 (hardback). US$90.00

Among the myriad ways to reconstruct past climates, pollen cores is one of the most powerful. As long as analogies to modern climate hold, pollen rain composition can reveal temperature and moisture changes as far back as the Cretaceous. Unfortunately, the skewed geographic provenience of the available analyses limits the utility of pollen cores for global climate reconstruction. A recent map showing the provenience of pollen cores worldwide (Myriad ways to reconstruct past climate, 2001, p.658) has only Europe, the United States, and a few places along the coasts of South America as thoroughly sampled. Eurasia, Australia, Asia, Africa, and the Amazon basin are almost devoid of pollen sites.

What little we know about past pollen composition in the Amazon is summarized in the first two chapters of the Amazon Pollen Manual and Atlas by Colinvaux, Oliveira, and Patiño. Amazon lake sediments consistently hold large concentrations of pollen, in spite of the surrounding flora being largely insect-pollinated and producing relatively little pollen. Pollen concentrations in a lake in lowland rainforest in Brazil are about 247,600 grains/cubic microliter and those in a lake in eastern Ecuador are about 100,000 grains/cubic microliter. These values compare favorably with pollen concentrations in lake sediments in the United States or Europe. Similar sedimentation rates may be due to tropical lakes having larger catchment areas than temperate lakes or to tropical rain torrents bringing more washoff pollen. In any case, abundant pollen sediments exist. However, someone needs to identify the pollen in them.

The Amazon contains an estimated 80,000 species of vascular plants, and the Amazon Pollen Manual and Atlas illustrates fossil spores of just 421 species. Yet, analyses of the presence and abundance of these few pollen types contain significant signal of past forest communities and thus, climate. The authors, who have worked in neotropical palynology for most of their careers, chose the pollen types to be illustrated from their reference collections of about 2,000 extant Amazonian pollen species. The illustrated pollen grains are the most abundant or decisive elements seen in Amazonian samples. …