Oct 21, 2010

Life Above the Jungle Floor

A Biologist Explores a Strange and Hidden Treetop World
by Donald Perry

This book kind of wasn't what I expected, but I enjoyed it nevertheless. I thought I was going to get a detailed description of the author's explorations in the upper stories of tropical jungle, but that was only one aspect of Life Above the Jungle Floor. It starts with the author explaining how he got into biology studies, and his excitement when he found that (at the time) the treetop habitat was an unexplored area; most research in jungle life had taken place in the understory, which was easy to reach. He describes a lot of his methods in reaching the upper heights, using climbing ropes and even moving on pulleys along a rope strung between two large trees, so he could lower himself down into fragile canopies that would not support the weight of a person. I liked reading all the parts about the interesting animal life- insects and birds mostly- that he encountered, the mutual relationships between ants and their host plants, one very creepy passage where he lowered himself into an enormous hollow tree.

But there is also a very interesting section on how life evolved to take advantage of treetop heights, and even new (to me) theories on why the dinosaurs went extinct. I had never heard this idea before, but Perry says that the idea of an asteroid striking the earth is not well supported, it doesn't explain how early birds survived the catastrophe plus he notes that there were lots of small reptiles, which could hibernate in holes and survive even better than small mammals, so why didn't they? Instead, he posits that the advent of flowering and fruiting plants, which spread their seeds wider via mammal and bird dispersal, is what brought about the demise of dinosaurs (which took millions of years, not one sudden event). Because the flowering/fruiting plants were more successful than earlier primitive plants the dinosaurs lived on, they became more prolific, and when their food source got shouldered out, the dinosaurs began to disappear. At the same time mammals and birds exploited the new food source and evolved intricate mutually beneficial relationships with the plants. Maybe I've gone on too much about this, but it was very interesting and made sense to me. Just look at places like Hawaii, where so many native plants have gone extinct due to invasive (more aggressive/successful) plants crowding them out- aren't the native animals disappearing there, too? Anyhow, it was all very thought-provoking. The fourth focus of the book is, of course, concern about how rapidly the forests are being depleted, but that was only discussed in the final chapter.

Rating: 3/5 ........ 170 pages, 1986

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