Summer reading: recommended books, on topics from growing potatoes to imagining other universes.

Is "summer science reading" an oxymoron? Isn't this the season for light fare, and don't science books belong on the cabbage-and-mutton side of the menu? The Science News staff doesn't think so. Here we recommend a picnic basket of lively books. Scientists soaring through trees and camping out with ivory-billed woodpeckers are our action heroes. Storytellers describe natural living, raising flowers for profit, and surviving as original Americans. Our dose of summer school seriousness comes from authors trying to explain climate change, the religion-science divide, and the universe itself. Enjoy.

--Keith Haglund, Managing Editor

Aerial Oceans THE WILD TREES: A Story of Passion and Daring RICHARD PRESTON Random House, 2007

"The forest canopy is the Earth's secret ocean" Richard Preston writes in The Wild Trees. That anything in California can remain secret might seem incredible, but Preston includes among the world's enigmatic canopies that of the temperate redwood rain forest stretching from San Francisco to Oregon. Somehow, much of this forest remained unexplored until the 1990s.

That was when Steven Sillett, a botanist at Humboldt State University, and oddball knife salesman-cum-tall-tree hunter Michael Taylor independently began surveying the redwoods in earnest. Sillett started as a lichen fanatic, donning long spikes and rigging elaborate rope systems to hoist himself to the top of 300-foot giants. Taylor, overweight and afraid of heights, stayed below and searched for the tallest trees with a protractor and binoculars.

Meanwhile above, Sillett and his colleagues discovered unexpected life. Rare salamanders, beetles, earthworms, and voles make their homes in the aeries. Shrubs and small trees thrive in the loamy soil piled within crotches of the redwoods. Sillett once found an 8-foot-tall spruce growing on a redwood, and he cataloged huckleberry, hemlock, laurel, and even Douglas fir in the canopy.

Preston weaves Taylor's and Sillett's stories with that of Marie Antoine, who also began as alichen lover. Midway through the book Antoine and Sillett meet and fall in love. The two consummate their relationship in a hammock strung some 30 stories above ground-untethered from safety ropes--a scene that offers a frisson rarely found in science journalism. Sillett later proposes to Antoine in the treetops, and they find a minister willing to ascend a redwood to marry them. Antoine sews flowing lichen into her veil.

In his previous books about deadly pathogens, such as the bestseller The Hot Zone (1994, Random House), Preston captured the inner lives of scientists by immersing himself in their world. He does the same here, learning advanced climbing techniques so that he can join his protagonists in the canopy, notebook in hand. While a conservation message is implicit, Preston wisely avoids preaching. Instead, through the adventures of Sillett, Taylor, and Antoine, The Wild Trees engenders a sense of awe. Redwoods live 2,000 years or more, we learn; they survive hurricane-force gales and hellish blazes; they drink the fog. In short, they're amazing.

The Wild Trees almost is too. But for long stretches, Preston's passive tone turns tedious.

Despite this, the story is engaging, especially Preston's portrayal of the oddball Taylor, who ends the book married and an engineer, and with an unabated redwood habit.

Inexplicably, Preston fails to detail Taylor's biggest triumph, an expedition to measure the world's tallest known tree, a 379-footer that Sillett and Taylor discovered and named Hyperion. Preston wrote about the adventure in the Oct. 6, 2006 New Yorker but provides only a glancing reference at the end of the book.

Perhaps he simply ran out of time. A reader can only hope the remaining redwoods--only 4 percent of the trees found 200 years ago--don't suffer the same fate.--B. VASTAG

Think Globally, Eat Locally ANIMAL, VEGETABLE, MIRACLE: A Year of Food Life BARBARA KINGSOLVER, WITH STEVEN L. HOPP AND CAMILLE KINGSOLVER HarperCollins, 2007

Although best known as a novelist, Barbara Kingsolver is also a biologist, mom, wife, and former science writer. In this lively and informative book, all those facets of her life shine through. Husband Steve Hopp and daughter Camille also contribute to this family story of "a year in which we made every attempt to feed ourselves animals and vegetables whose provenance we really knew ... and of how our family was changed."

The book, in a nutshell, is about good food and how to grow and cook it--all with an eye to being gentle with the environment. It's a new, hybrid science that one might call "ecogastronomy." Kingsolver's talent is to make her family's radical change of lifestyle sound both practical and appealing. All readers, urban dwellers included, could adopt at least some of the strategies that the authors describe.

In 2004, Kingsolver, Hopp, and their two daughters left Tucson for a southern Appalachian farm. The family spent a year remodeling the farmhouse and preparing the land. Parents and daughters developed ground rules. First, they would try to eat only vegetables and fruits grown in their own garden or within a short radius of their home base. Most dairy products and meats would be purchased locally, and the clan would raise its own chickens and turkeys. Nine-year-old daughter Lilytook on responsibility for the chickens, which she promised to not make pets. "It's OK," Lily assured her mom. "I won't name them."

The period covered in the book starts in March 2005 and ends a year later. Beginning with April's asparagus harvest, continuing through traditional year-end feasts of turkey and pumpkin pie (the family did have to forgo cranberries), and closing the following spring with contemplative reflections on the family's adventure, Kingsolver recounts a year's local-food experience.

Living off the land had its ups and downs, and one of this book's charms is its candor. March was the "hungry month" that demanded dependence on canned, frozen, or dried fruits and vegetables. But July and August were bountiful with dozens of veggies, particularly zucchini and tomatoes, ripe for harvest. Kingsolver describes each month's bounty from the perspective of a scientist (explaining, for example, the reproductive cycle of angiosperms) as well as that of a steward of the environment.

In sidebars, daughter Camille, a college student, recounts the experience from her generations view. She offers recipes and a sample meal plan for each month. Included, for example, are four recipes for potato salad--each using a different variety of seasonal potato.

Hopp, a professor of environmental studies, contributes sidebars that put his family's experience in a global perspective. He discusses the ethical, environmental, and health consequences of high-volume animal-feeding operations, as well as chemical pesticides and fair-trade agreements.

Using the Dewey Decimal system, my local library shelved this book under Category 641--Food and Drink. That classification will help others find Animal, Vegetable, Miracle, but it doesn't do justice to this unique and thought-provoking book. A cross-reference to "Miracle" might do the trick.--L. HARTEKER

The Art and Science of Blooms FLOWER CONFIDENTIAL: The Good, the Bad, and the Beautiful in the Business of Flowers AMY STEWART Algonquin Books of Chapel Hill, 2007

A rogue lunch is a terrible thing. "One of the first rules of operating a flower shop is to never, ever store a sack lunch in the cooler, out of fear that a piece of fruit could ruin the roses, writes Amy Stewart. An apple, for instance, will release a lot of ethylene, which will speed plant-tissue aging.

Stewart's Flower Confidential takes readers behind the bud vases for a lively exploration of the breeding, growing, and marketing of cut flowers. She starts with flower breeding the old-fashioned way by the late Leslie Woodriff. Stewart calls him a horticultural legend but says that people in his hometown remember him as "the eccentric old guy in the broken-down greenhouse along the highway." Few outside his profession know his name, but just about everyone has seen his work: the big, fragrant, upturned Star Gazer lily.

Moving to the high-tech extreme, Stewart describes the Florigene company's quest for a blue rose. Genetic engineers succeeded in getting roses to carry a gene that produces delphinidin, a pigment that looks sky blue under the right circumstances. But so far, Stewart reports, the roses are more violet than true blue.

In the $40 billion cut-flower trade, farms in South America and Africa rush their products to Europe, North America, and Russia. "Flowers today may be better traveled than the people who buy them" Stewart writes. She shows readers Ecuador's rose farms, where premium flowers have enormous heads on straight, 5-foottall stems. Their growers ship most of these luxurious blooms to Europe and Russia.

Flowers may be pretty, but the farms producing them outside the United States don't have such an attractive reputation. Stewart discusses allegations that the operations exploit workers and abuse pesticides. She finds a mixed picture but offers a hopeful note, describing certification programs to let consumers know that growers have met certain standards for growing and labor practices.

Stewart follows flowers from their growers to their buyers, such as those at the Dutch auctions at Aalsmeer, which handle 20 percent of the cut flowers in the world. The book ends, as so many flowers do, on Valentine's Day in a flower shop. This particular Feb. 14 is a weekday, and that's good. Florists tell her that sales crash when the date falls on a weekend.

A more serious woe for U.S. florists comes from supermarkets that set out buckets of bouquets. These sellers are expanding their market share, even as many break the basic flower-shop rule. As a Dutch import-export representative laments to Stewart, "They put everything together--the cheese, the fruit, the flowers--all that ethylene. It's awful."--S. MILIUS

The Heat Is On PLOWS, PLAGUES, AND PETROLEUM: How Humans Took Control of Climate WILLIAM F. RUDDIMAN Princeton University Press, 2005

An explosion of human population and burgeoning technology use are causing planet-warming greenhouse gases to build up in Earth s atmosphere. That statement is true today, was true at the beginning of the industrial revolution nearly 2 centuries ago, and--in what probably is a surprise to most people--was true thousands of years ago.

In a straightforward and evenhanded way, climatologist William F. Ruddiman explains how researchers reconstruct our planet's climatic history. One technique they use, for example, is to track the varying concentrations of gases in the atmosphere by analyzing bubbles trapped in ice caps worldwide. The longest records, from Greenland and Antarctica, cover hundreds of thousands of years and chronicle how concentrations of greenhouse gases such as carbon dioxide and methane have varied.

For the past few hundred millennia, the amount of carbon dioxide in our atmosphere has gone up and down roughly every 100,000 years, while methane has followed a 22,000-year timescale. Those changes, Ruddiman explains, correspond to long-term cycles in Earth's orbital path that influence the seasons and the amount of the landscape occupied by wetlands.

But the natural patterns have been disrupted, he writes. After the peak of the latest ice age, about 11,000 years ago, both carbon dioxide and methane at first declined in the expected way. But about 8,000 years ago, the amount of carbon dioxide began to increase, with methane following suit about 3,000 years later.

What caused these anomalies? The simple if surprising answer, Ruddiman argues, is human activity. About 8,000 years ago, long before the industrial revolution, people began clearing forests to create agricultural land. As populations grew, the carbon dioxide that would have been soaked up by trees instead remained in the atmosphere. Then, around 5,000 years ago, especially in Southeast Asia, people began to irrigate their rice paddies--in effect, expanding the amount of landscape covered by methane-generating wetlands.

Ruddiman finds other evidence that human activity affected greenhouse gases in the atmosphere before large-scale industrialization got under way. Occasional but substantial decreases in carbon dioxide during the past 2,000 years coincide with plagues that devastated populations across broad regions. Following the largest pandemic of recent time--the one that European explorers caused in the Americas in the 1500s--reforestation of neglected farm plots caused atmospheric concentrations of carbon dioxide to drop substantially, cooling worldwide average temperatures by as much as 0.1[degrees]C.

Such temporary changes in carbon dioxide concentrations pale in comparison to those caused by people today, when industries and automobiles are increasing greenhouse gases in the atmosphere by almost 1 percent every year.

Plows, Plagues, and Petroleum is a primer on natural variations in Earth's climate and on how human activity is having even more of an impact. While some readers might find it disturbing that people have been influencing the planet's climate for millennia, others may be even more alarmed to think about climate changes yet to come.--S. PERKINS

The Parting of the Ways BEFORE DARWIN: Reconciling God and Nature KEITH THOMSON Yale University Press, 2005

William Paley was not the simpleton his modern detractors claim he was. It was Paley, Archdeacon of Carlisle, England, who in his 1802 book Natural Theology made famous an argument concerning a pocket watch. Such a machine could not arise of its own accord, he observed, but must have come about through deliberate acts of design and creation. So too, he said, the wondrously complex natural world requires a designer.

Paley's argument was a good deal subtler than that, however. Keith Thomson, a professor emeritus of biology with a deep understanding of theology, takes readers on an intellectual tour through the 2 centuries preceding the 1859 publication of Charles Darwin's Origin of Species. During that period, geologists and biologists were beginning to put together a recognizably modern account of our planet and the life it carries. Their novel ideas provoked a fretful conflict with long-established Judeo-Christian views.

Of all the scientists' new ideas, none was more awkward than the notion of change. Geologists realized that landscapes slowly transform. The discovery of fossils corresponding to no modern creature showed that forms of life must have disappeared.

Change posed a problem for theologians who believed in a perfect creation, because perfection to them implied permanence. But an additional perplexity loomed. If the disparate elements that make up the world were always changing, how could the ensemble continue to function in such an apparently harmonious way?

Guiding us through the work of James HuRon, Charles Lyell, Erasmus Darwin, David Hume, and many others, Thomson explains how some thinkers were happy to evict God from a world ruled by science. But he sympathetically portrays the struggle of those who wished to maintain their religious views. Paley's Natural Theology represents the culmination of that struggle. The example of the watch calls attention to the way in which many parts must mesh perfectly to create a functioning machine. Similarly, Paley said, the human eye is composed of many parts working toward a common purpose. That purpose, moreover, depends on the behavior of light, which has nothing to do with biology.

Only God's enduring influence, Paley insisted, can explain how the complex assemblies of life fit so well in their varied environments on Earth, and how their fitness persists as those environments change. Although deeply impressed by Paley's eloquent presentation, Charles Darwin had the genius to hit on a very different solution: adaptation through natural selection. After Darwin, many thinkers began to see scientific and religious views on life's origin as inescapably at odds. Thomson concludes that Paley couldn't help but fail in his attempt to keep science and religion in harmony. But unlike most of today's critics of evolution, he was no blind defender of dogma, and he sought earnestly to answer the questions that science presented.--D. LINDLEY

Nice Guys Finish Last IVORYBILL HUNTERS: The Search for Proof in a Flooded Wilderness GEOFFREY E. HILL Oxford University Press, 2007

Nobody remembers who comes in second. That rule shouldn't apply to Geoffrey Hill, the Auburn University ornithologist whose small band of swamp scientists last year reported sightings and recordings of ivory-billed woodpeckers, presumed extinct since 1944, in the Florida panhandle. The group's report came more than a year after the famed Cornell Laboratory of Ornithology splashily claimed to have rediscovered the bird in Arkansas. Hill presents better evidence and the promise of more to come.

The Cornell team wasn't the first to report sightings, or even to supply blurry pictures, of the "Lord God Bird" since its alleged demise. Hill reviews serious but flawed studies of ivory-billeds along with a thread of mostly crackpot sightings, including one from the Pea River in south Alabama that came over his office transom in 1995.

It wasn't until April 2005, after the Cornell group had made its announcement, that Hill took the 1995 report semiseriously. He and two young colleagues made a kayaking trip to the Pea River but quickly decided that the decimated forest there was inhospitable to ivory-billeds. On a whim, they drove a few miles south to Florida's Choctawhatchee River. Woefully unprepared for even a casual paddle on the fiver and its tangled tributaries, the three nevertheless found a vast, little-known, nearly intact tract of perfect ivory-billed habitat, rich in hardwoods and cypress.

At about 7:30 on their first morning there, the least-experienced birder among the scientists swore that he saw an ivory-billed, and all three men heard several of the double knocks that distinguish the woodpecker from all other birds in the United States.

From there, Hill and his makeshift crew began a secret, yearlong hunt. They remain confident that the 14 sightings they describe and about three times as many audio recordings are indeed of the supposedly extinct birds. The impression is that the study area must be teeming with the birds. Many of the large nest cavities that they found were fresh cut, for example, and tree bark had apparently been chiseled by unusually powerful woodpeckers.

Yet this exciting story ends in frustration, without any proof-positive still or motion picture. Like the Cornell researchers in Arkansas, Hill and his crew came away with a Lousy video"--in their case, showing three (!) smudges that might be ivory-billeds--that Hill considers "far from conclusive proof" of the birds' presence.

Recounting the tale with a pleasing balance of human drama and scientific cool, Hill also interjects a wonderful chapter on what is and isn't science. "When we hunt for ivorybills ... we are not doing science. We are not trying to explain processes of nature. We are searching for a bird. We are birding," he writes. Hill ends his book by inviting other birders to help him look for ivory-billeds. "I end this book in the middle of the adventure," he writes, leaving the reader with a sense that the group could get its definitive picture any day. Evidently, that's not the case so far, as

Hill indicates on his Web site (www.auburn.edu/ivorybill), which features updates of the 2006-2007 season's search.--K. HAGLUND

The Grandeur That Was the Americas 1491: New Revelations of the Americas before Columbus CHARLES C. MANN Vintage Books, 2005

For people who accept the Hollywood version of Native Americans-small, nomadic bands living in bucolic landscapes-this book could come as a bit of a shock.

The romanticized images of Native Americans that pervade popular culture are largely wrong, Mann writes. Current archeological thinking is that many Native American societies were neither small nor environmentally benign.

Indians built technologically advanced civilizations, particularly in present-day Mexico and Central and South America. With populations often exceeding those of 15th-century European cities such as Paris, urban centers built by the pre-Columbian civilizations radically altered their natural surroundings. Fly low over these landscapes today, as Mann vividly recounts, and one can see the faint outlines of massive drainage ditches, arrow-straight berms, and geometrical mounds built by these ancient people.

During the past few decades, archaeologists have pieced together much of the history of sites such as these. Advances in scientific techniques--from epidemiology and climatology to satellite imagery and DNA testing--have begun to reveal the rich history of the Americas before Christopher Columbus arrived in 1492. Yet this new understanding has remained mostly unknown outside academia. Mann tells of his son being taught the same quaint falsehoods about Native American culture that Mann himself had learned as a schoolboy 30 years earlier.

One of those misconceptions is that New World societies lacked the intellectual and technological achievements of the Old World. Mann points out that cultures in the Americas independently developed agriculture about 10,000 years ago and gave rise to the technologically complex Olmec civilization 3,800 years ago.

Native American peoples "invented a dozen different systems of writing, established widespread trade networks, tracked the orbits of the planets, created a 365-day calendar (more accurate than its contemporaries in Europe)," Mann writes. The Maya discovered the mathematical concept of zero, which mathematicians peg as a seminal human accomplishment.

The most advanced and populous civilizations--the Maya, Wari, Tiwanaku, Inca, and Aztec--all inhabited lands south of the Rio Grande. But early European colonists and traders wrote of even present-day New England as a densely populated land. If later explorers found a wilderness peopled only sparsely by small tribes, it was because diseases inadvertently brought by the Europeans had already depopulated local societies, Mann asserts.

A journalist rather than an academic, Mann has avoided writing a scholarly chronology--a style he derides as "one damn thing after another." Instead, he highlights the juiciest stories and most interesting bits of information, keeping this information-packed book enjoyable to read.--P. BARRY

Much Ado about Nothing MANY WORLDS IN ONE: The Search for Other Universes ALEX VILENKIN Hill and Wang, 2006

By its very definition, cosmology deals with the universe as a whole--everything. These days, however, in true Seinfeld fashion, cosmology is often about nothing too. More precisely, cosmologists seem most concerned with empty space, also known in physics parlance as the vacuum.

Alex Vilenkin is among the cosmologists who believe that many, perhaps infinitely many, parallel universes could exist, each with its own kind of vacuum. We happen to live in one such bubble, with no hope of ever coming into contact with another. To get to that startling conclusion, Vilenkin offers a short and sweet introduction to the most hotly debated ideas in modern cosmology--ideas to which the author has himself made key contributions.

The trend began in the early 1980s, when physicist Alan Guth--now of the Massachusetts Institute of Technology--and others showed how they could resolve a number of perplexing difficulties in the Big Bang scenario by postulating an explosive epoch called inflation. Guth imagined an early universe in which the vacuum had an intrinsic energy that acted like antigravity. During the earliest moments of the Big Bang, this repulsive force would have expanded the universe from microscopic size to cosmic scale in a zillionth of a second. Then, as the initial kind of vacuum turned into another, the antigravity would have suddenly disappeared. The universe would have settled back to a sluggish pace of expansion that would later allow galaxies, stars, and planets to form.

But in 1998, astronomers discovered that Guth's antigravity never really went away. Although much weaker now than it was during inflation, antigravity even today seems to push galaxies apart. The vacuum dominates the universe's destiny.

One of the greatest puzzles in this scenario is why the vacuum should end up in one state rather than in another. The mystery only deepened in 2003, when physicists tried calculating the vacuum states using string theory, the yet-untested "theory of everything" that would replace elementary particles with tiny, vibrating strings. By their reckoning, the magnitude of the vacuum's energy in our modern universe is just one among a stupendous number ([10.sup.500]) of possibilities.

Vilenkin excels at illustrating these and many other difficult concepts, peppering his account with personal anecdotes. His explanations are among the tersest in the popular cosmology literature, yet also among the least watered down.

As Vilenkin admits, his claims are not uncontroversial. Some scientists regard speculation about other universes as unscientific, since no experiment can ever be done to directly detect them. String theory itself has recently come under fire for being disconnected from experiment.

But the speculative nature of the subject becomes one of the book's strengths. The author, for example, toys with the idea of visiting regions within our universe's bubble that could be inhabited by replicas of ourselves--an idea that physicists have shown isn't entirely out of the question. Want to take a vacation in such a parallel universe? When it comes to summer reading, it doesn't get much more escapist than this.--D. CASTELVECCHI

BY THE SCIENCE NEWS STAFF