Conservation / Tree Health

By W. John Kress, Gary A. Krupnick

By Alexandra Martins

They are descended from ancestors that lived more than 50 million years ago and have faced all kinds of challenges.

But today they are still standing, but only in one place on the planet.

In the Sierra La Laguna, in the state of Baja California Sur, in northwestern Mexico, lives the only population of a species of oak known as encino arroyero .

By: Stephanie Pappas

Ancient trees, the venerable sentinels of forests, may preserve genetic diversity that helps woodlands thrive for thousands of years, a new study suggests. 

A new study involving more than 100 scientists from across the globe and the largest forest database yet assembled estimates that there are about 73,000 tree species on Earth, including about 9,200 species yet to be discovered.

The global estimate is about 14% higher than the current number of known tree species. Most of the undiscovered species are likely to be rare, with very low populations and limited spatial distribution, the study shows.

By Patrick Greenfield

There was perhaps no one better than Cornelius H. Muller—one of twentieth-century America’s most notable oak fanatics—to document the continent’s most mysterious oak trees. In July 1932, the horseback-riding botanist first encountered Quercus tardifolia while collecting samples in the steep-cut canyons of Texas’s Big Bend National Park. Muller jotted down details of the twigs (slender, somewhat fluted), buds (hairy at the tip), leaves (dull blue-green), and branches (short, stiff). He anointed it with a Latin name that referenced the tree’s late-season leaf development.

Schwenda, Germany—Last summer, Friederike and Jörg von Beyme stood on a bramble-covered, Sun-blasted slope outside this small town in eastern Germany. Just 4 years ago, the hillside, part of a nearly 500-hectare forest the couple bought in 2002, was green and shady, covered in tall, neatly arranged Norway spruce trees the couple planned to cut and sell.

By: Grant Seagull

A tree disease first spotted 9 years ago in Ohio is now a leading threat to one of eastern North America’s most important trees. The poorly understood malady, called beech leaf disease, is spreading rapidly and killing both mature American beeches and saplings, new research shows.

“This study documents how rapidly [the disease] has spread since its first observation in 2012,” says Robert Marra, a forest pathologist at the Connecticut Agricultural Experiment Station who was not involved with the work.

WASHINGTON (AP) — Richard Barclay opens a metal drawer in archives of the Smithsonian Natural History Museum containing fossils that are nearly 100 million years old. Despite their age, these rocks aren’t fragile. The geologist and botanist handles them with casual ease, placing one in his palm for closer examination.

The Morton Arboretum and United States Botanic Garden (USBG) announce a new partnership to advance the conservation of threatened trees in the United States, with a special focus on native oak species. The partners will develop threat assessments, conduct field work to resolve taxonomic questions and collect seeds for planting in conservation collections, and advance the work of the Global Conservation Consortium for Oak (GCCO).