Joshua Tree National Park lacked its usual corps of park rangers during the government shutdown, and Beth Touchette mourns one of its small, but metaphoric victims.
One particular image of a destroyed Joshua tree haunts me. It was not a large tree, but it had two spiky-leaved branches, formerly reaching towards the sky, that Mormon settlers thought resembled the supplicating arms of a prophet. Several Joshua trees were chopped down or driven over during the January government shutdown. Unsupervised visitors also toppled gates, and carved roads through the sensitive desert ecosystem.
A springtime walk in a Joshua tree “forest” is a unique delight. The limited water means the trees are well-spaced, and wild flowers carpet the desert floor. Buzzing insects and scurrying lizards are everywhere.
They also have a fascinating natural history. They are pollinated by the slow-moving yucca moth, who lays it eggs in the tree’s flowers. In exchange for reliable pollination, the Joshua tree sacrifices a portion of its seeds to the moth’s larvae. Charles Darwin described it as “the most wonderful case of fertilization ever published”. Cave excavations have revealed that Joshua tree fruit was a favorite food of the ancient ground sloth. These Volkswagen Beetle-sized animals transported the seeds up to ten miles, and provided a bonus dose of dung fertilizer.
The warming climate, drought, and expanding cities are reducing the suitable habitat for the Joshua trees. Young seedlings especially are struggling. The forests in the national park are not replacing themselves. The ground sloth is not available to help the trees migrate to cooler, moister environments.