The Earth Surface Dynamics section of the USGS provides this excellent collection of graphics, depicting range maps for more than 100 common North American tree species. From Abies amabilis to Yucca brevifolia, these color maps may be viewed or downloaded (.pdf, .zip, tgz). Most of the ranges depicted here were digitized by Elbert L. Little, Jr. (USDA Forest Service) for vegetation-climate...

In 1971, hundreds of tree seedlings germinated aboard NASA's Apollo 14 mission to the moon. A few years later, they were planted around the nation, often with much fanfare. However, no one kept a systematic record of these plantings, and as a result, the whereabouts of most of the trees remains a mystery. Visitors can read or listen to an account of the history and current status of them at this...

The Internet continues to evolve as a global library, allowing free and easy public access to an increasing number of valuable documents. One such treasure, found in the archives of the USDA Forest Service St. Paul Field Office website, is _ Silvics of North America_, a substantial publication describing "the silvical characteristics of about 200 conifers and hardwood trees in the coterminous...