After half a century of slow decline due to land conversion and damming of rivers, screwbean mesquite suddenly began dying rapidly and in large numbers. The die-off was first noticed in the early 2000s by tribes in the Yuma area of southwestern Arizona. Early reports describe a “mysterious malady” which was sweeping through populations, leaving only a few unhealthy survivors in its wake. Within years the die-off had moved up the Colorado, Gila and Salt Rivers.
Despite the ecosystem-changing implications of losing this foundational species, no concerted attempt was made to figure out what was causing so many trees to die so quickly. Restoration proved unsuccessful. The trees would succumb to the mysterious killer a few years after being planted in the wild. Many land managers gave up trying to use the tree in restoration plantings and soon a community-defining tree species had become a rarity over most of its southern range. Fortunately, large populations were still thriving in the north, along the Virgin River and in more scattered populations of southern Nevada.
After a quiet period of half a decade, though, the second wave of the die-off began. An avian biologist working in Shoshone, California watched as the large, healthy stand of screwbeans in which he’d been monitoring bird nesting for over a decade was decimated within two years. By 2014 only a few stragglers remained. He reached out to biologists and land managers and the community formed a working group to figure out what was causing the trees to die and whether something could be done about it. That is when EcoCulture got involved.
