“Nature is not more complicated than you think, it is more complicated than you can think.” — Frank Edwin Egler 

Frank Egler was a plant ecologist who, among other accomplishments, assisted Rachel Carson in her writing of her profoundly impactful book, “Silent Spring.” As Egler so correctly stated, ecological systems are exceptionally complex with myriads of connections between species along with intertwining physical and ecological processes that create the dynamic “canvas” upon which species exist. Conservation often operates in response to ecological crisis. Protect this or that now or else some species will almost certainly go extinct. Responding to an ecological crisis requires rapid responses in financial resources, public support, and guidance from the best available science, however imperfect and incomplete. Implementing rapid response to complex ecological conflicts is at best a challenge.

Back in the 1970s, a professor from UC Riverside, Dr. Wilbur (Bill) Mayhew, saw an ecological crisis unfolding on the Coachella Valley floor. Previously, the 100 square miles of active sand dunes on the valley’s floor created what must have seemed like an insurmountable impediment to land development. The first human residents here, the Cahuilla, built their villages beyond the margins of the “sand sea,” tucked into the mouths of canyons where there was dependable water and protection from the fierce winds that moved the fine aeolian sands down wind. There they lived a largely sustainable lifestyle for thousands of years that included annual migrations to higher elevations during the hot summer months, taking advantage of the food resources along the way. The first non-indigenous colonists, in the 1800s and early 1900s, had the same idea in terms of where to live on the valley floor, resulting in conflicts and one-sided cultural clashes with the Cahuilla people. A critically important story to tell – but here my focus is on an ecological crisis. The non-indigenous colonists did not have the wisdom born of living sustainably in one place for thousands of years. Their focus was anything but sustainable, responding to a sort of gold rush, although here the value was not a precious metal, it was land.

As the margins of the expanse on sand dunes filled up with settlers and entrepreneurs, there began an incremental incursion into the dune field. If anyone thought about it at all I am sure they would have argued that the sand dunes were a sterile landscape, bereft of life, and so how could anyone argue with the “improvements” they envisioned and began to implement. Of course, the sand dunes here, and for that matter sand dunes elsewhere on our planet, are not lifeless expanses. Rather sand dunes are seemingly evolutionary “factories” catalyzing the production of new life forms uniquely adapted to this landscape. On the Coachella Valley sand dunes there is a plant, a lizard, and (at least) a handful of arthropods found nowhere else on earth. Along with these endemic species there was an abundance of other creatures, such as desert iguanas, long-tailed brush lizards, pocket mice and kangaroo rats, and much more. Bill Mayhew understood this cornucopia of life better than anyone, and rather than sit on his academic laurels and watch it all be destroyed by rampant golf course developments, he chose to act. The legal nexus was what were then relatively new federal and state laws, their respective Endangered Species Acts. Listing the Coachella Valley fringe-toed lizard, and later the Coachella Valley milkvetch, were relatively easy tasks. No one with any knowledge of these species could argue that by further developing their sand dune habitat that they would soon be extinct. The lizard was listed in 1980. That should have stopped any future sand development of the sand dunes, but it didn’t even slow it down.

One problem was that the State and Federal agencies were unsure how to implement these relatively new laws. Another problem was that protecting a sand dune was complicated. Sand dunes have many of the same characteristics as rivers. They have a point of origin, a sand source where sand is being eroded from rocks and cliffs by a flood event (or in the case of a river, a spring, or glacier, or snowfield.) Then there is flow away from that point of origin. For both, that original flow is based on water following gravity. The sand grains suspended in a flood are eventually deposited on the land when the floodwaters subside. From there the wind takes over sorting the sand grains and blowing the finer grains into dune structures that continue their movement across the desert as long as the winds still blow.

Imagine that you are charged with protecting a river. You need to protect the headwaters along with the full course that the river travels, no dams. The same is true for sand dunes. Protect the sand source, the channel the floodwaters follow, the spreading basins where sand is deposited, and the wind the pushes the sand into mobile dunes, and no structures that would block the movement on sand grains from the start of their journey to the dunes and the path that the dunes would then take. If we knew back in the early 1900s what the future would hold for the Coachella Valley, we could have designed a perfect protection plan. However, by 1980 there were already “dams” in place, blocking sand flow. Roads, train tracks, Interstate 10, golf courses, schools and people’s homes stood in the way of what was once the natural sand flow through the valley, and the process that sustained the dune habitat for the lizard and all the other species dependent on these dunes.

Any protection plan would thus be imperfect. Nevertheless, plans, however imperfect, were created that protected those sites that had the best chance for sustaining the dunes. It started with a Coachella Valley Fringe-toed Lizard Habitat Conservation Plan (1986) and that later was morphed into the Coachella Valley Multiple Species Habitat Conservation Plan (2008). It was soon apparent that those dune areas that were deemed unsustainable because there was no opportunity for continued sand flow, and so were unprotected, were quickly becoming “sand starved." No fringe-toed lizards, no Coachella Valley milkvetch continue to live there. What is particularly gratifying is that on those sites that were protected because there was some chance for them to sustain their sand dune ecosystems, that the lizards and milkvetch and endemic insects are all still present and thriving.

There are ongoing threats to those remaining functioning sand dunes and looming large is climate change. We are seeing incremental upslope movements in many desert plant and animal species in response to hotter and drier conditions. However, for dune adapted, dune obligate species, the only equivalent option to moving upslope to cooler-wetter climates, is moving further west toward the Windy Point sand dune areas where it is much cooler and where rains are far more dependable. Of course, freeways, multiple lane highways and a double railroad track corridor would keep lizards from actually moving. Still, if the lizards were being stressed by climate change what we should see is dwindling populations on the hotter-drier eastern (Thousand Palms) populations, compared with more stable or even growing populations on the western (Windy Point) dune sites.

Our Community Scientists have been helping conduct lizard surveys this Fall and so we have data to test whether these predictions are in fact true. The ongoing drought conditions have continued into 2022 and so we should be able to see if there is a temperature and rainfall impact on the lizards. On our Windy Point sand dune plots we found an average of six hatchling fringe-toed lizards per plot – very good numbers! In a more centrally located, somewhat warmer and drier dune off of Gene Autry Trail we averaged 2.2 hatchlings per plot, numbers consistent with our climate change predictions. Then, on our hottest and driest plots east of Thousand Palms we should find few or no hatchlings, yet there we averaged almost eight hatchlings per plot. Great news, but very confusing. Clearly, we have much more to learn about these complicated systems.

Nullius in verba

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