Rescue: free from confinement, danger, or evil

I would add another environmental-based definition: “to slow, halt, or reverse a threat that could otherwise lead to local or broad-scale extinction.”

Modern climate is resulting in hotter, drier conditions across the deserts of the world, hotter and drier than most species have ever experienced. Across the hottest and driest portions of our desert otherwise abundant species like brittle bushes and side-blotched lizards have not been replacing senescing adults with vigorous youth at levels that would indicate sustainable populations.

But then in the late summer of 2022 there were two heavy rainfall events that seemed to have reversed that trajectory, offering hope. The immediate effects of that uncharacteristic summer precipitation were the new leaves and flowering of perennial shrubs in a manner that was reminiscent of a healthy spring. Bees and butterflies and grasshoppers responded to this unseasonal cornucopia with an explosion of life, putting an exclamation mark on just how adaptable and resilient our desert species can be.

One of the best indications that these summer storms may have been a “rescue event” has been the abundance of seedling brittle bushes and palo verde that have sprung up in the midst of the decaying skeletons of their parents and grandparents. Palo verde seedlings are now lining washes and alluvial fans. Ocotillos leafed out, put on new growth and some bloomed. Cacti are fat and happy. All are signs for cautious optimism. The seedling trees and shrubs are particularly heartening. However, for all desert perennial plants, this seedling stage is when the plants are the most vulnerable. Mature plants have deep roots reaching for the vestiges of past rainfall events collected in underground rock fissures. Mature cacti and Joshua trees hold and store water in their spongy stems and trunks. Seedlings lack both extensive root systems and water storing capacity. To survive, seedlings need rain. To survive the next year and beyond, these seedlings will need rain. The amount of rain that falls over the next few months will determine whether the seedlings with form a new cohort replacing their parents and grandparents or will desiccate beyond the ability to recover.

The rainfall predictions for the effects of modern climate change across our deserts is for less winter rain, and of course higher temperatures and thus higher evaporation and so even less rain available to support life. What is far less predictable is how much summer rain we will receive. Worldwide, higher temperatures mean higher evaporation and so higher levels of water vapor in the atmosphere. In many areas that will mean more rain, especially more summer rain. The summer rain we received in 2022 demonstrated how versatile, how adaptable desert life can be. What is not clear is whether summer rain will become sufficient to rescue desert life, or if it will remain infrequent and unpredictable, offering occasional hope only to have that hope dashed by subsequent droughts with little or no seedling survival.

Rather than proclaiming that we are on the verge of a cataclysmic extinction event, or conversely that that nature is so adaptable that there is nothing to worry about, our dedicated community of naturalists are out measuring change. We are seeing what are perhaps centuries-old jojoba “trees” die, and at the same time bursts of life in response to those summer rains. Entire palm oases are drying up while bighorn sheep are recovering from what seemed like the brink of extinction just a few decades ago.

Nature is complex. Unlike a physician taking our temperature and blood pressure, and from that getting a pretty good idea of our general health, there is no one or two criteria that will act as a barometer of the health of nature. Naturalists are not myopic. Rather our community of naturalists are interested in all of nature. That lack of focus can sometimes make it difficult to get very far on a trail very fast – we are looking at everything. However, that holistic view of nature may be the best way to access the affects of climate change, to distinguish short term gains from true rescue events.

Nullius in verba

Go outside, tip your hat to a chuckwalla (and a cactus), think like a mountain, and be safe