To walk in a forest in West Texas feels like a form of grace. The Davis Mountains are the state's largest “sky island” – a place of green pastures, a wooded country above a sea of desert.

Oak and juniper, aspen and madrone. And on high slopes and canyons, trees that tower above the rest – ponderosa pines. They're majestic – and a foundation of rich biodiversity.

In 2011, Texas had its driest year on record. The drought, and ensuing wildfires and insect attacks, killed more than half the ponderosas in the Davis Mountains. The forest habitat is now at the brink.

Saving those trees – giving the ponderosas a chance in a changing climate – is a top priority for conservation...