holyoutlaw

Douglas W. Tallamy

Note: I read a library copy of the hardcover published in 2007. The link above is to a revised trade paperback edition, with an expanded resource section and updated photographs.

“Bringing Nature Home” thoroughly covers all aspects of how and why to use native plants in a home garden. The problem with alien plants is simple: they disrupt the food web by being inedible to insect herbivores. Insects have specialized gut bacteria and enzymes that neutralize (or even utilize) the defenses of their native plants. Some can only eat a single type of plant. When supplies of native plants are replaced by alien plants, the insects starve. This ripples through the food web, as most birds feed their nestlings insects, which have the highest dose of fat and protein and provide the best energy resource.

With no insects eating native plants, there are no insects for the birds to eat, resulting in fewer birds. The larval forms of many butterflies and moths need native plants for survival as well. Their adult form may be generalist enough to get pollen from nonnative species, but if their larval forms have no food, there will be no adults.

Tallamy provides a table towards the end of the book showing that even if an alien plant was introduced a couple hundred years ago, it still provides little or no food or resources to native insects. A few species might have made a transition to the new plant, but the native will host dozens more. In a few cases, an alien plant is close enough to a native that the insects can eat with no problem. But again, insects get more benefit from the native plant, and not all species hosted by the native can transition to the alien.

By reintroducing native plants into the home garden, we provide food for the insects and the birds that eat them. The chapter “What Should I Plant?” addresses this. Because this book is written for a national audience, the advice has to be very general. Tallamy focuses on trees of especial benefit to Lepidoptera because butterflies and moths are charismatic and attractive to people.

The original publication of this book in 2007 sparked a great conversation about gardening with natives. There is now a website, plantanative.com, that provides links to native plant societies, suggestions about what to plant, and more. Nowadays there are numerous books, organizations, and websites about using native plants. This interest was sparked in part by the earlier publication of “Bringing Nature Home.” There is still a long way to go, but progress is being made.

Two good resources for this area are the Washington Native Plant Society, and Landscaping for Wildlife in the Pacific Northwest, which I’ll look at soon.

Mirrored from Nature Intrudes. Please comment over there.

The Wild Trees: A Story of Passion and Daring
Richard Preston

Studying the tree canopy of redwoods is a new field, developed in the last twenty-five years or so. The Wild Trees chronicles that development, focusing on the personalities of the people driven to search for the tallest trees in the world, and then to climb them to see what’s up there.

The personalities are interesting, it’s true. Finding the tallest tree in the world isn’t enough of a driving interest to receive funding, so the initial research is done on the weekends by a convenience store clerk. However, his persistence in this search brings him into contact with others, such as Stephen Sillett, and together they discover a completely new world.

It used to be thought that forest canopies were just the leaves and branches of the trees, maybe some bird nests, but nothing very interesting. Just about every canopy, at every level, is a startlingly diverse ecosystem. Preston compares the experience of the original tree climbers to that of Jacques Cousteau, discovering a new world with his scuba equipment.

A redwood tree might looks like one straight stem from the ground, but a tall tree will send out several trunks as it reaches its height. And if a windstorm breaks off one of those leaders or sub-trunks, new trunks sprout in its place. The broken trunk might get caught in branches and never reach the ground. Over time, the new growth around it will fuse with it. Dirt accumulates in the joins of the multiple trunks; in this dirt, bryophytes and epiphytes start to grow. And, somehow (the mechanism isn’t known yet) copepods from the ocean live up there, as well as salamanders.

Considering how patchy the redwood forest remnants are, it’s a little staggering to think what what the canopy might have been before logging. How much more massively complex the redwood canopy must have been, when it could have stretched unbroken for miles. Even so, it’s possible to walk from tree to tree in some cases. Wisely, the exact locations are kept secret and only a few biologists and tree scientists know them.

One of the main discoveries of people researching possibly the largest organisms on this planet involves one of the smallest organisms: The role that a small lichen, Lobaria, plays in the fertility of the canopy and the forest as a whole. The lichen is prominent in very old Pacific Northwest forests, but it can take thousands of years for it to grow and spread through a canopy. This means that even relatively old forests (a few hundred years, and currently considered old growth) might not yet be at their ecological climax.

The book is described as “narrative nonfiction,” which means Preston uses some of the story telling tools of fiction to build an arc. And there were times when I felt genuine tension in reading the book. I can guess the general circumstances of even a very well-done thriller, but there were times reading this book I had no idea how an event would turn out. We’re carried through the lives, loves, and losses of all the people involved in this research.

Having said that, I’d have liked the book to focus more on the science and a little less on the personalities. At least a guide for further reading (or viewing — there have been TV documentaries about Sillett and canopy research). I liked that scientific research isn’t all glamorous (particularly anything involving Australian leech forests) and that scientists sometimes have messy personalities. But I would have liked more about the canopy itself.

Bonus! Here is a TED talk by Richard Preston about climbing in the redwoods.

Mirrored from Nature Intrudes. Please comment over there.