Botany Episodes

Fire can erase blackbrush stands quickly, while invasive annual grasses can make subsequent fires more likely.

Burros are magnificent animals. What happens when unmanaged herds overwhelm the desert habitat around them? Dr. Jen Anderson joins Chris Clarke to describe her efforts to restore the Sonoran Desert Sanctuary near Alamo Lake in western Arizona. She recounts damage to palo verde trees, disappearing wildlife, and years of seeking help from the Bureau of Land Management. The conversation brings together desert conservation, federal wild burro management, animal welfare, and hands-on restoration—and includes a detour onto the bridge of Star Trek: Enterprise.

Why do deserts need protection? For the 150th episode of 90 Miles from Needles, Chris Clarke returns to the reasons this work matters: deserts remain widely misunderstood, receive less scientific attention than they deserve, and cannot be protected without confronting questions of justice. Listeners Kimberly, Nancy, and Diane share what the desert means to them, while Chris considers wildfire, Joshua tree science, environmental inequality, the border wall, urban heat, and the love that ultimately lies behind conservation. An after-credits report examines where the podcast has traveled during its first 150 episodes—and where its coverage still needs to go.

Kate Scott reports from a tree sit in Lochiel, where activists occupied the last of four landmark cottonwoods after contractors destroyed the others for double-wall construction through the San Rafael Valley.

A personal history of Cima opens into the evolutionary partnership between Joshua trees and Shasta ground sloths, asking how a plant adapted to past climate shifts can migrate now that its most effective seed disperser is extinct.

Desert tortoise biologist Tim Shields explains experimental tools for deterring ravens, confronting invasive schismus grass and measuring ecosystem health—work intended to give future restorationists practical ecological leverage.

Conservation biologist Nick Graver explains how climate change, invasive grasses and human-caused fire undermine Joshua tree recruitment—and why shutdowns and federal cuts obstruct the long-term research and coordination recovery requires.

For his father's 91st birthday, Chris revisits an essay connecting a formative 1966 desert journey, the mutual dependence of Joshua trees and their moths, and the literal kinship joining every generation of life.

Brendan Cummings explains California's Western Joshua Tree Conservation Plan, the compromises behind the 2023 law and the difficult work of protecting climate refugia while development and fire continue.

On the Dome Fire's fifth anniversary, Chris returns to Cima Dome to confront the loss of its vast Joshua tree forest, the spread of invasive grasses, uncertain restoration and his own enduring solastalgia.

Cameron Mayer reads poems about honey mesquite, Mojave aster and travels through the Great Basin, showing how botany, photography and language can deepen attachment to overlooked desert places.

Parker Lloyd tours the Nature Center at Pia Okwai, where Tracy Aviary and West Valley communities are restoring former industrial land as wildlife habitat and an environmental-justice gathering place.