Despite lacking any formal background in ecology, I really enjoyed this book. It uses what physicists might characterize as very Fermi-esque, back-of-the-envelope arguments to suggest, among other things, why biodiversity shouldn't be a surprise; why life, if it's present at all on a planet, is more likely to be widespread than isolated; and why the notion of the rain forests as the "lungs of the earth" is wrong. (Our real benefactors: marine phytoplankton, especially because they die and sink; see @88.)
When I first began the book I thought I'd be like an outsider intruding on some family argument: the author is at pains to distinguish his approach from the traditional one in ecology textbooks. Rather than approaching the topic through entities such as genes, individuals, populations, David Wilkinson (DMW) approaches it through processes such as the Second Law of thermodynamics, tradeoffs, hypercycles and photosynthesis (check @13 or see the chapter titles for Chaps. 2-8 for the complete list). I needn't have worried, since the presentation is quite transparent to an outsider to the field (certainly so if you're coming from a physical sciences or engineering background). Although the level of argumentation is sophisticated (more like a perspective piece in Science or Nature than a popularization), the level of biology and chemistry background necessary to follow the argument is probably around freshman level. There's also an extensive glossary at the end, if you can't tell your Archaean from your Phanerozoic.
An organizing concept is thought-experiments about what processes would be necessary for life on a planet not necessarily the earth. But it's far from abstract -- DMW's day job is as an empirical scientist rather than theoretician, and there are plenty of empirical papers cited. (Pace another reviewer, however, the book expressly and repeatedly disclaims being about "applied ecology," and makes no pretence of addressing management issues.) He's also quite up-front when he feels there isn't enough data to figure out whether, e.g., some process might accelerate or mitigate global warming (see @108).
Many of the results are quite counter-intuitive, at least if one's intuition is shaped by cable TV "Planet in Peril" extravaganzas. In terms of their effects on regulating the planetary environment so that it remains habitable, DMW suggests that prokaryotes are far more important than polar bears or pandas, and parasites than predators. (Admittedly, he doesn't address the issue of species charisma, which makes pandas better than any Prochlorococcus as poster-organisms for changing human behavior.) But the real fun of the book is the simple, common-sense way in which these results are derived.
The list of references at the end is excellent, and comprises more than 20 pages (the main text is only about 140). I also admire an author who cites one of his own papers only to mention that he was wrong (see discussion of dark pigments in leaves @105).
My one gripe is that the copy editor for this book (or the more senior Oxford UP editor who perhaps chose to forego one) should be summarily fired. There are numerous typos, run-on sentences and non sequiturs, and sentences missing commas where one is necessary in order to make sense. One should not have to waste time puzzling over statements like "As the sun's energy has increased [cite], the CO2 greenhouse has decreased helping [sic] to regulate the Earth's surface temperature," @ 103. (Should be "decreased, helping", with quite the opposite meaning from the original.) The net effect is like eating a very tasty lunch in the company of dozens of persistent flies. I read the hardcover edition, but from Amazon's "look inside" feature the paperback seems to preserve these irritations. But don't let that deter you from reading this very clever and intriguing book.