MY AMERICAN SCIENTIST
LOG IN! REGISTER!
SEARCH
 
RSS
Logo IMG

BOOK REVIEW

World Watch

William Schlesinger

Global Change and Terrestrial Ecosystems. Brian Walker and Will Steffen (eds.). 691 pp., Cambridge University Press, 1996. $120 cloth, $39.95 paper.

A central goal of the International Geosphere-Biosphere Program (IGBP) is to understand the response of the earth's terrestrial ecosystems to global change—including changes in climate, chemistry and direct human impact. This volume contains the plenary papers from the first science conference of the IGBP program, "Global Change and Terrestrial Ecosystems," held in Woods Hole, Massachusetts in May 1994. The book focuses on what we need to know in order to understand our planet better. Like most symposium proceedings, there is much variation in the value of its 28 chapters, which are arranged in five sections (Ecosystem physiology; Ecosystem structure; Agriculture, forestry and soils; Ecological complexity; and Earth system science). Models abound, but the modelers themselves seem wary of the output.

There is consensus in this volume, perhaps best seen in Christian Korner's chapter on the response of complex systems to elevated carbon dioxide suggesting that the response of individual plants in simple experiments cannot be used to predict the response of entire ecosystems to elevated carbon dioxide. Add to that simultaneous exposures to increased nitrogen deposition and rising global temperature, as outlined by F. A. Bazzaz and his colleagues, and we find ourselves with only a scanty ability to predict how our planet will function in the next century.

There is less consensus regarding biodiversity, with some authors suggesting that a substantial amount of nature's diversity is redundant (C. S. Holling et al.), whereas others suggest that diversity is significant in determining ecosystem response to stress (F. S. Chapin et al.). Large variation in species behavior allows some compensatory responses that hold ecosystem-level function at relatively constant levels. Because the variation in species behavior is so great, ecosystem modelers must categorize species into a few "functional groups" that can be assumed to behave similarly. Another volume in this series, Plant Functional Types, begins this process quite effectively.

The real driver of change in terrestrial ecosystems is, of course, human population growth. The IGBP has a separate program, The Human Dimensions of Global Change, to address this difficult issue. I am struck, however, with the futile nature of predicting the future condition of our planet—for instance, global net primary production—when population-driven changes in land use are not yet incorporated into most global models. A chapter by R. Leemans, describing the model IMAGE 2, is a refreshing attempt to incorporate these factors in an integrated assessment of the effect of humans on the emission of greenhouse gases. Pointing to human population and economic growth, Jan Goudriaan concludes that at an "average rate of change of 2 percent per year, those processes will probably have a much larger impact on food security and crop production than the dynamics of climate change."—William H. Schlesinger, Botany, Duke University

 

Connect With Us:

    Pinterest Icon Google+ Icon Twitter Icon Facebook Icon Sm


Pizza Lunch Podcasts

African Penguins"Penguins are 10 times older than humans and have been here for a very, very long time," said Daniel Ksepka, Ph.D., a North Carolina State University research assistant professor. Dr. Ksepka researches the evolution of penguins and how they came to inhabit the African continent.

Because penguins have been around for over 60 million years, their fossil record is extensive. Fossils that Dr. Ksepka and his colleagues have discovered provide clues about migration patterns and the diversity of penguin species.

Click the Title to view all of our Pizza Lunch Podcasts!


Subscribe to Free eNewsletters!

  • Sigma Xi SmartBrief:

    A free daily summary of the latest news in scientific research. Each story is summarized concisely and linked directly to the original source for further reading.

  • American Scientist Update

  • An early peek at each new issue, with descriptions of feature articles, columns, Science Observers and more. Every other issue contains links to everything in the latest issue's table of contents.

  • Scientists' Nightstand

  • News of book reviews published in American Scientist and around the web, as well as other noteworthy happenings in the world of science books.

    To sign up for automatic emails of the American Scientist Update and Scientists' Nightstand issues, create an online profile, then sign up in the My AmSci area.


EMAIL TO A FRIEND :

Of Possible Interest

Book Review: The Greatest Show on Earth

Nanoview: Two Antarctic Tales

Nanoview: A Life with Whales

Subscribe to American Scientist