This marks the end of my internship with USGS Henderson in the Mojave Desert. It has been a fantastic experience, and I have learned so much! It has been a pleasure to work with amazing researchers and contribute to fascinating and relevant research! Working on a study related to Desert Tortoise, Gopherus Agassizii, has been very eye-opening. Before this internship, I had not worked with an endangered species, and I was fascinated to learn more about the regulations and legislation in place to protect endangered species!

Most significantly, I have learned an entirely new flora, informed by the Jepson Manual, as well as my mentors and other botanists in the area. From Phacelia to Cryptantha and Sphaeralcea to Oenothera, I have expanded my botanical knowledge considerably! It was a great experience to use a new flora (the Jepson Manual) and to think about different ways to identify plants (i.e. examining at Cryptantha “nutlets” for species identification, using bracts for Ephedra ID, etc.). I enjoyed exploring and discovering small portions of the Mojave, and the experience has inspired me to explore the Sonoran and Chihuahuan deserts as well.

In addition to plant identification, I learned some new techniques for data analysis. I learned that R is an extremely powerful analysis tool, if you know how to use it! I took some time to read up on R code and packages, which was very helpful. While I didn’t end up using it for this internship, I certainly plan to use it in the future!

After performing some preliminary analyses on our juvenile Desert Tortoise vegetation survey, I began to consider some important concepts. For example, species are often clumped by “native” vs “nonnative” species. However, these categories, while useful in certain circumstances, can be misleading. For example, with regard to nutrition, studies have shown some nonnative species to be detrimental to tortoise health and others to be beneficial. Bromus rubens has been shown to be of poor nutritional quality for tortoises, while Erodium cicutarium is actually quite nutritious, especially for juvenile tortoises. While these are both incredibly abundant nonnative species, they offer completely opposite nutritional characteristics. Discoveries such as these demand a more comprehensive set of questions than simply: “how do native vs. nonnative plants compare in terms of nutrition?” Instead, one must take into account various factors, including origin, abundance, caloric value, mineral concentrations, etc. These questions help drive truly innovative studies.

I also gained more GIS experience throughout my internship. I had the opportunity to explore the multitude of functions provided by ArcMap to accomplish tasks such as map ping our vegetation sampling effort and selecting candidate sites for our oil well vegetation project. Incidentally, I have also learned more about oil well production on the Colorado Plateau than I ever expected to know!!  Here’s a photo of a mesa nearby our field sites.

My internship exceeded my expectations, and I am very happy to have had the experience. I hope to work in this area again in the future! I am sad to leave the Mojave, but I’m sure I will be back again.

Thanks to everyone who played a role in my internship experience, particularly my mentors!

Cheers!
Daniel

The last three weeks I have been working on a project surveying vegetation recovery at oil well sites across the Colorado Plateau. Our sites have taken us to Bluff, UT, the Moab area, and Virgin, UT, near Zion National Park. Many of these wells are very old (some as old as the 1920s). This makes finding them quite difficult, as GPS was not around in the 20s… It has been fascinating, though, to find each of the wells and to assess the vegetation effects of disturbance!

At each site, we establish 30m transects and measure both cover as well as density. For the purposes of recovery, we are only measuring perennial plants (with annuals included, the task would be much greater!!). We then find a suitable reference site (an adjacent area with similar soils, topography, and ideally free of disturbance).

Along the way, we have identified and learned to recognize countless new species, including Lygodesmia grandiflora, Oenothera pallida, Muhlenbergia pungens, Dalea candida var. oligophylla, Machaeranthera tanacetifolia, Townsendia incana, and Chaetopappa ericoides. And of course some interesting Utah lizards…

I’m looking forward to looking at the data more closely to tease out the differences in vegetation recovery between sites, especially the older ones from the 1920s!

Til next time,

Daniel

The past month has been spent analyzing our annual vegetation data from juvenile Desert Tortoise sites, and we’ve come a long way! We have also been searching across most of Utah and some of Colorado (Colorado Plateau) for potential post-oil well vegetation monitoring sites! This new project is a departure from our previous work, and will be a nice getaway from the heat in the Mojave! This has involved a tremendous amount of filtering through GIS data and looking at satellite imagery for promising sites. The criteria involve clusters of sites, each containing: sites where Artemisia tridentata and/or Coleogyne ramosissima grow (or would, if an oil well hadn’t been established), a site from each decade from 1950-2000 (when the oil well was plugged and abandoned), and that each cluster fall within certain climatic constraints. This is no small task when faced with over a thousand potential sites! But it has been a great way to learn more about GIS and get a look at post-restoration oil well from the air!

In other news, the weather has been incredibly unpredictable, with temperatures climbing well above 110 F and incredible thunderstorms at the same time! Incredible precipitation events have led to flash floods and sights like this dry lake bed near Primm, NV, which is not-so-dry anymore!

Meanwhile the perennials are sending off seed, and the summer annuals are waiting for their moment to sprout from this monsoon weather!

Here in the Mojave Desert, our annual vegetation collection has come to a close. Although some juvenile Desert Tortoises are still foraging out of their burrows, most of the useful annual plant material has dried up and blown away. This means we are on to the next task of entering our mountains of data sheets into a digital format! This component is actually quite rewarding because it allows one to look back on the entire field campaign, from the beginning when methods were still being developed, to the end, when our methods were refined. It’s a great feeling knowing you’ve learned a lot since you started! The Mojave never ceases to amaze me, with new plants emerging just when you thought nothing could possibly bear the heat, now rising into the 108-110 range. Although the annuals have (with the exception of a few Eriogonum species) senesced, some Cacti and a few other perennials are in full flower.

Now begins the task of using the loads of data we collected to answer the questions we asked at the beginning of the study. Some examples include: 1) Which annual plant species do juvenile Desert Tortoise target and why? 2) Is there a significant difference in species composition and biomass between our three distinct sites? 3) Is juvenile Desert Tortoise health correlated with species diversity, higher biomass, or any other parameters measured at our sites?

To answer these questions, we need to organize our data such that we can use statistical programs to detect differences in species richness, biomass, etc. We also need to determine the nutritional value of a few key species. Finally, we need to use foraging observations, collected by another researcher, to determine species targeted by juveniles.

I find this part of the project really fun, because it involves investigating trends, being creative in analysis techniques, and finally (hopefully) being able to tell a small story about juvenile Desert Tortoise behavior and/or nutritional needs as well as describing the habitats they prefer.

So begins the long, sometimes tedious, but always rewarding, data analysis phase!

‘Til next time,
Daniel

Eucnide urens

Hello from the Mojave Desert! For the last month, we have been busy trying to quantify the forage available for juvenile Desert Tortoises! Each day brings us to a new field site, where we collect as much data on diversity and available biomass as possible. We have come across some fantastic species, and my knowledge of Boraginaceae species (especially those in the Cryptantha genus) has grown by leaps and bounds! Here’s a photo of Eschscholzia glyptosperma (when it was still flowering).

Most species are either seeding or senesced at this point, so our field campaign is beginning to wind down. The next few weeks will be spent weighing biomass samples and preparing for our next project (TBA). We will, however, return to our surveys later this summer when late summer annuals begin to emerge!
We continue to come across the occasional tort in the field, but they are beginning to spend less time out of their burrows as it gets warmer.

However, with increasing temperatures, snakes appear to be more frequent, especially gopher snakes…

They can be a bit of a surprise when you’re looking down at a GPS suddenly find yourself standing only feet away!
I’ve learned so much already, and am looking forward to learning a lot more as we start our new project in early June!

Til next time,
Daniel

Henderson, NV

Hello!

It is spring in the Mojave Desert, and we have begun our field season in full force! As interns with USGS Henderson, NV, it’s our job to characterize the annual (and, to some extent, perennial) vegetation available to juvenile Desert Tortoises. We’re talking quite small tortoises – imagine a four-inch long tortoise!


Despite the widespread drought in the west, the Mojave actually received above-average winter precipitation this water year, and, as a result, we are seeing incredible annual growth! Many of the spring wildflowers are in full bloom, and we’ve been learning loads of new species each day. It seems as though there are another five species flowering each time we visit our field sites! We’ve been kept busy keying out new species, especially Cyrptantha sp. (the CLM guide to Cryptanthas has been a fantastic resource).

Besides amazing new plants, we’ve also seen a number of resident and translocated Desert Tortoises, snakes, and birds!
I am looking forward to adding more species to the list, and learning more about the Mojave as the season goes on! What an amazing opportunity to learn about plant and wildlife ecology!!

‘Til next time,
Daniel Boyes