Book review: A 100 million year love affair with American plants

Paul V A Fine

doi:10.21425/f5fbg12403

Abstract

news and update ISSN 1948‐6596 book review A 100 million year love affair with American plants A Natural History of the New World, by Alan Graham 2010, The University of Chicago Press, 408 pp. ISBN: 9780226306797 / 9780226306803 Price: $110 (Hardback) / $40 (Paperback); http://www.press.uchicago.edu/ I teach a class called “The Ecosystems of Califor‐ nia”, and my students always ask the question: “Will global climate change cause trouble for California’s plant communities?” I find it impossi‐ ble to give a short response, not because I doubt the grave predictions about future warming, but because many of California’s species have a long history in North America, and have already lived through ten glaciation cycles, including the recent extinction of the Pleistocene megafauna (which must have wrought major ecosystem change). Some species are old enough to have endured the massive cooling and drying that changed North America from the mostly frost‐free and drought‐ free continent that it once was in the Eocene. On the other hand, even if non‐anthropogenic climate change has offered little more than an evolutiona‐ ry bump in the road when examined from a 50 million year perspective, contemporary human‐ mediated disruptions may be catastrophically des‐ tabilizing to ecosystems and human civilization in the short term. Thus, answering how the biota will respond to current climate changes and distur‐ bances requires an understanding of the magnitu‐ de of the changes that have already occurred and Alan Graham’s new book provides exactly this context. A Natural History of the New World repre‐ sents a wonderful synthesis of Alan Graham’s vo‐ luminous career studying the American flora. This narrative includes detailed descriptions of plant communities of the Americas, and includes a com‐ prehensive review of paleobotanical evidence and interpretations regarding how changes in floras have coincided with global climate changes and geological events in different biogeographic re‐ gions of the Americas over the past 100 million years. The book opens with a very long description of all of the different biomes and vegetation types in the Americas, starting with the North Pole and ending with Tierra del Fuego. My favorite chapter, by far, is Chapter 3, which succinctly gives the best and clearest description I have ever read of the tools used to put dates on past events. I very much enjoyed these lucid explanations of how global sea levels are reconstructed, how reversals of the earth’s magnetic field are detected, and how radiometric dating works. I will definitely use this in my undergraduate teaching. The next chap‐ ter describes the techniques that paleobotanists use to identify micro and macrofossils and also how macrofossil assemblages are used to estima‐ te past climates. Here, I was disappointed that the explanation of leaf‐margin analysis did not include any discussion of Peter Wilf and students’ work of why serrated leaf margins may be correlated with colder climates (Wilf 1997, Royer and Wilf 2006). Graham then divides the past 100 million years into four sections: the Middle Cretaceous through the Early Eocene, the Middle Eocene through the Early Miocene, the Middle Miocene through the Pliocene, and the Pleistocene and Quaternary, to discuss how the major climatic and tectonic events have impacted the evolution and assembly of plant communities, and how and when (and why) those assemblages begin to ap‐ proach recognizably modern forms. I greatly enjo‐ yed these sections, as they provide a great review of the paleobotanical research for each time pe‐ riod broken down by geographic area – a synt‐ hesis of time and place that is often very difficult to piece together from other books and articles which give a more local or taxon‐specific focus. The book is very well referenced throughout, a great service for readers who want to follow up on more details about particular regions and pa‐ leobotanical studies. It is indeed striking how few paleobotanical studies are published for tropical areas, and botanically megadiverse, important areas like the Amazon basin have only very few well‐studied sites over large stretches of time © 2011 the authors; journal compilation © 2011 The International Biogeography Society — frontiers of biogeography 3.2, 2011

Highlights

I teach a class called “The Ecosystems of Califor‐ nia”, and my students always ask the question: “Will global climate change cause trouble for California’s plant communities?” I find it impossi‐ ble to give a short response, not because I doubt the grave predictions about future warming, but because many of California’s species have a long history in North America, and have already lived through ten glaciation cycles, including the recent extinction of the Pleistocene megafauna
Some species are old enough to have endured the massive cooling and drying that changed North America from the mostly frost‐free and drought‐ free continent that it once was in the Eocene
Answering how the biota will respond to current climate changes and distur‐ bances requires an understanding of the magnitu‐ de of the changes that have already occurred and Alan Graham’s new book provides exactly this context

Summary

Introduction

I teach a class called “The Ecosystems of Califor‐ nia”, and my students always ask the question: “Will global climate change cause trouble for California’s plant communities?” I find it impossi‐ ble to give a short response, not because I doubt the grave predictions about future warming, but because many of California’s species have a long history in North America, and have already lived through ten glaciation cycles, including the recent extinction of the Pleistocene megafauna (which must have wrought major ecosystem change). Answering how the biota will respond to current climate changes and distur‐ bances requires an understanding of the magnitu‐ de of the changes that have already occurred and Alan Graham’s new book provides exactly this context.

Results

Conclusion