Hunting for Botanical Biodiversity, Joshua Tree National Park

Lost Palms Oasis, Joshua Tree National Park

Imagine if we could gather together an enthusiastic multitude of biologists and interested citizens to comb through a location on a single weekend, seeking to identify every living thing that occurs in that one spot. Think of how much we could learn about ecological complexity, and of how the dimension of our knowledge of that place would unfold like a Chinese fan. It is like we are taking a biological snapshot, capturing a record of everything that is there at that point in time. Holding such a gathering is the aim of a “Bioblitz”, or Biodiversity Hunt: to positively identify as many species as possible over a day or two in a delineated area.
Staff at Joshua Tree National Park organized a series of four Biodiversity Hunts over the past three years, assembling more than 100 people to search, identify, and report on the biological richness of the park’s desert wetlands, the focus of this project. Rancho Santa Ana Botanic Garden (RSABG) botanists have been present at all four of these hunts, applying their botanical expertise to assist the National Park to identify plant species that reside within their boundaries, and more generally benefiting knowledge of Southern California’s botanical richness.

In March and April a group of botanists from the Garden, including Naomi Fraga, Sarah Degroot, Evan Meyer, Abby Hird, Loraine Washburn and Jessica Chu participated in the last two of these four Biodiversity Hunts. We spent four full days in Joshua Tree, doing thorough surveys for plants that occur around Cottonwood Springs and the Lost Palms Oasis, near the south entrance, and in Smithwater Canyon in the northwest of the Park. We joined birders, herpetologists, entomologists, and arachnologists, as well as students, photographers, and interested community members in a wide-ranging survey of these remarkable desert wetlands.

In March at Cottonwood Springs and Lost Palms Oasis, RSABG botanists fanned out into the washes and slopes, identifying common and dominant species as well as hunting for microsites where less common elements might be found, such as against a north-facing cliff face, in a more humid seep, or where the soil became richer in clay. We appreciated the shade of palms and cottonwoods as we hunted along the edges of the pools, where we found ferns (Cheilanthes covillei), rushes (Juncus acutus), and orchids (Epipactis gigantea) in the wetter parts of the oases.

By the end of the March weekend, the collected effort of all bio-hunters had identified more than 558 species, including more than 200 species of plants and 300 species of insects, as well as 32 bird species, 12 reptiles, seven mammals, and one amphibian species. For our part, we found many plant species that had not been documented before for this location in the Park, and at least one species that was new to the Joshua Tree park plant list.

The April Biodiversity Hunt at Smithwater Canyon focused on one of Joshua Tree National Park’s richest areas for plant diversity, due to its higher elevation, perennial water flow, and steep canyon walls that form diverse microhabitats for plants, as well as its location in the transition between the Mojave and Sonoran deserts. We were fortunate on Friday to be joined by Tasha La Doux, a Ph.D. graduate of RSABG’s program, who now divides her time between Joshua Tree and the Sweeney Granite Mountains Desert Research Center in the Mojave. We were also joined by Darryl Slate, an enthusiastic and knowledgeable amateur botanist who lives near the park. In our two day hunt at Smithwater Canyon we found 160 species of plant, both common and rare species, as well as contributing the sole sighting of a speckled rattlesnake to the reptile list. Due to the dry spring in the desert, the abundance of spring annuals has been quite modest throughout the Park, resulting in an under-representation of total plant diversity.

Earth’s biological richness belongs to all of us. A deep appreciation of the biodiversity of a place can stem from an understanding of the geological and biological history of that place, and can also help the human population of the planet deepen its connection to the other species that share their piece of the planet. We hope, also, that encouraging people to know the organisms around them will deepen their caring for wild species enduring presence on Earth. RSABG’s conservation efforts aim to increase the chances that California’s flora survives intact to the world of our great-grandchildren. Field studies such as our Biodiversity Hunt participation at Joshua Tree helps this effort by assuring that we know what grows where, while also helping federal resource managers do their job effectively, by helping them to know more about the biological diversity they are protecting.

Rare Plant Treasure Hunt

Several years ago Rancho Santa Ana Botanic Garden (RSABG) teamed up with the California Native Plant Society (CNPS) through a contract grant from the Bureau of Land Management (BLM) and the Department of Fish and Wildlife to do rare plant surveys across California deserts as part of the Rare Plant Treasure Hunt (RPTH) program. Last year marked the third year for RPTH, a program created and named by Josie Crowford of CNPS.

A Rare Plant Tresature Hunt group travels out to Castle Peaks. Photo: Kim Clark

It is largely a citizen-science program with the goal of getting volunteers out in the field to experience California wild places and assist in rare plant surveys. These surveys largely target rare plant populations that haven’t been revisited in more than 20 years in order to evaluate the current status of these populations.

Many people may be under the impression that the desert is nothing rocks, lizards and an occasional spiny plant—an open wasteland to be crossed to get to Las Vegas or Lake Havasu. But California deserts hold more than 35 percent of the flora of California and have some of the areas of highest diversity for the state. There are many botanically unexplored mountain ranges and valleys out there. In 2012 alone, there were five plant species found in California deserts new to science described by RSABG scientists and researchers.

The Rare Plant Treasure Hunt program largely focuses on the California deserts often associated with the development of renewable energy projects. There are currently thousands of acres proposed for possible development, of which a great deal has had little botanical exploration.

It is the goal of the RPTH program to get volunteers out to these places to experience them first hand and to educate others on California’s diverse flora and the importance of its conservation.

Coryphantha alversonni in the Big Marias Mountains. Photo: Kim Clark.

Volunteers from the Sierra Club, the Desert Survivors Organizations, HabitatWorks, The Wildlands Conservancy, CNPS chapters and subchapters from across California have often participated with Rancho Santa Ana Botanic Garden in the Rare Plant Treasure Hunt. But many volunteers were not affiliated with any particular organization, but were just interested in joining the group to explore and learn about the desert and to have a personal experience with these wild places while doing so.

The spring field season in 2012 was one of the driest years on record for the California deserts; most areas got only 0.01 millimeters of rain or absolutely no rain at all. Watching the doppler in the winter of 2011-12 was often like watching a blank screen as there was so little weather action. Watching the weather stations and dopplers frequently helps plant scientists predict which areas may have germination or bloom. But even in dry years, the desert rarely disappoints and almost every area visited had at least one rare plant population if not dozens.

The summer field season seemed to the opposite as some parts of the California deserts received the most summer rain they have received in more than a decade. The eastern Mojave in particular had an amazing summer bloom and RSABG/RPTH participants were able to document around 100 rare plant populations on just a few trips.

A total of 24 trips were made in 2012. These trips ranged from day trips to three-day excursions into very remote places. We started in March at below sea level around the Salton Sea, topped out on Southern California’s highest peak on Mount San Gorgonio at 11,500 feet in July, and then headed back down to the lower elevations following the summer monsoonal storms in September. We documented around 300 rare plant populations. Many of these were newly documented. We trekked into the Panamint Mountains and found the type locality of the Panamint daisy (Enceliopsis covillei), which is the plant that has always adorned, and will continue to adorn, the CNPS logo; this population had not been revisited since Frederick Coville made the first collection of this plant in 1891 on the Death Valley expedition. The new species was later named for him. We found the first population of Abrams spurge (Chamaesyce abramsiana) in Imperial County in 100 years; all historic populations from Imperial County are likely extirpated due to development and agriculture. We documented many range extensions of rare plants, locating populations where they had never been found before. We provided information that aided in the evaluation of plant species for the CNPS inventory, including information about its abundance (or lack thereof!) in California and about threats to historic occurrences of a given species. We had many wonderful treks into some amazing places and spent many nights under star filled skies. All in all, it was a very successful and productive year.

If you would like to learn more about the Rare Plant Treasure Hunt program please visit the Rare Plant Treasure Hunt Website.