Using Annual Plants to Track Greenhouse Gas Hotspots: A CAZCA and SW-IFL Project

Using Annual Plants to Track Greenhouse Gas Hotspots: A CAZCA and SW-IFL Project

Did you know annual plants to tell us where greenhouse gas hotspots are? Central Arizona Conservation Alliance (CAZCA) has partnered with the Southwest Urban Corridor Integrated Field Laboratory (SW-IFL) to collect annual plants throughout the Phoenix Metro area for research to identify these hotspots.

Greenhouse gasses, a result of fossil fuel combustion, is one of the leading contributors of climate change. When fossil fuels are burned, they release large amounts of greenhouse gasses, including carbon dioxide, methane, and more, into the air and can be absorbed by plants. 


Over the past few months, the CAZCA,  Sky Island Alliance, and the Northern Arizona University SW-IFL team, accompanied by a strong volunteer force, have been collecting samples of annual plants all throughout Arizona, uploading photos and identifications to iNaturalist, and sending the samples to be lab tested for carbon levels.

By collecting and observing widely distributed annual plants, we are able to identify the locations of many greenhouse gas hotspots by measuring the amount of carbon in the plants. Plants that are closer to fossil fuel sources, or greenhouse gas hotspots, will have less carbon than those further away. By using annual plants instead of perennials, scientists will be able to compare year to year changes in greenhouse gas emissions. This data, when paired with SW-IFL’s Hestia project data, could help cities and stakeholders when developing climate change action plans to target and monitor greenhouse gas sources.

Learn more about SW-IFL and their current projects below. 

The Southwest Urban Corridor Integrated Field Laboratory (SW-IFL) is just one of four such field laboratories funded by the Environmental System Science Program of the U.S. Department of Energy. For more details on the program, visit the DOE Urban IFL home page.

Sonoran Desert: From Fire Proof to Fire Prone

Sonoran Desert: From Fire Proof to Fire Prone

Have you been wondering why there has been an increased number of wildfires throughout Arizona over the past few years? Southwest Fire Science Consortium (SWFSC) has recently released a report on this recent uptick, and identifies invasive grasses as one of the leading culprits for these fires. 

Why are these plants so bad? When invasive plant species are introduced, they can overtake entire landscapes, crowding out native plants and creating a monoculture. The Sonoran Desert typically presents as a desert scrub or desert shrubland biome. The plants in these spaces can be widely spaced or patchy in their distribution with open areas in between. These open areas make it difficult for fire to spread, making the desert somewhat fireproof. As invasive plant populations grow the open spaces between plants fill in making it easier for fire to spread, shifting the naturally fireproof desert scrub to a grassland, and our naturally fireproof desert becomes more fire prone. 

These invasives contribute to what is called the grass-fire cycle. Invasive grasses can spread and establish themselves quickly; they burn very hot, carry wildfires further than they may naturally go, and recover quickly after a fire. Native Sonoran Desert plants, on the other hand, can take several years to recover after a wildfire. Over time, invasive populations result in greater likelihood for wildfires to start and increase the size of future fires, limiting the ability for native plants to reestablish themselves. As the grass/fire cycle continues, our ability to control the invasive plant populations decreases, and wildfires start to occur more frequently, outside of the typical fire season (May-June). 

Read SWFSC’s full report below to learn more about these invasive grasses, what the future of our desert looks like, and what we can do. 

Stinknet: What You Need to Know About the Latest Desert Invader

Stinknet: What You Need to Know About the Latest Desert Invader

Have you seen, or maybe smelled, this plant? Stinknet (Oncosiphon piluliferum) has been popping up all across the valley this year, and poses a lot of threats to the ecosystem and the community.

Central Arizona Conservation Alliance is excited to announce the newest addition to our website, a page dedicated to educating the community on how to identify and manage stinknet! As a collaborative, we have joined forces with many of our partners to create a “hub” for resources about stinknet including information on identification, management and mitigation, allergens, resources for land managers, and more.  

Visit our new stinknet page to learn all about this invasive species. Only YOU can stop the spread of stinknet!

Women in Science

Women in Science

CAZCA is in the process of starting a new social media series where we will feature some of the amazing women in science throughout Central Arizona. Join us as we celebrate their remarkable contributions to the field and share their inspiring stories. Discover the passionate individuals who are pushing the boundaries of scientific knowledge and making a difference in our local community.

Stay tuned for our upcoming posts and get ready to be inspired!


If you are a woman in science or would like to nominate one, please fill out the form below!

Follow us on Facebook and Instagram to keep up with the latest news and events from CAZCA, and to learn more about these amazing women!

CAZCA Speaker Series Returns

CAZCA Speaker Series Returns

Central Arizona Conservation Alliance is excited to announce the return of our highly anticipated speaker series. This year, we are thrilled to bring you a lineup of distinguished individuals who will share their expertise and knowledge on various topics.

Prepare to be inspired as our speakers delve into captivating discussions on wildlife conservation, the importance of forging partnerships with local indigenous tribes, and much more.

Join us this fall and winter for an unforgettable experience!

Intern Jacob Zehner shares insight into HOA research project

Intern Jacob Zehner shares insight into HOA research project

Hello! I am a summer intern from Northern Arizona University working on a collaborative project between the Central Arizona Conservation Alliance (CAZCA) and the McDowell Sonoran Conservancy that aims to evaluate the current invasive species management efforts of Homeowners Associations (HOAs) across the Phoenix area.  Currently, our delicate desert ecosystems are succumbing to invasive plant species and the health and integrity of our local wildlife is at risk.  We believe working and potentially partnering with HOAs would be a valuable tool in fighting the spread of these invasive plant species because HOAs have the ability to enforce beneficial rules and regulations within their communities.

The major goals of this project include:
  • Evaluating HOAs in the general Phoenix area and determining which HOAs have already addressed invasive species in their covenants, conditions, and restrictions (CC&Rs) and which have not.
  • Developing questions and conducting interviews with select HOAs to understand their level of involvement on the issue of invasive plant species and if they would be interested in getting involved if they are not already.
  • Gathering information from conducted interviews to create a survey targeted specifically for HOAs to gauge overall interest on the issue.

We are currently finishing our evaluations for over seventy different HOAs in the Phoenix area.  While going through the process of documenting and analyzing our findings, we have also been working on getting our research submitted and approved by the Institutional Review Board (IRB) through NAU.  Once we have acquired approval, we will be able to begin reaching out to HOAs for interviews to continue towards our final project goals.

What I’ve learned:

Throughout the course of this project, I have learned that being able to effectively communicate is extremely important.  I was personally surprised to find out that the vast majority of the HOAs we evaluated did not mention invasive plant species at any point in their CC&Rs.  This made it more difficult to get our message across and emphasize the importance of our project goals.  Some of the science involved with our project can also be confusing to those not familiar with the terminology, especially with most of our audience being HOA staff.  Finding ways to simplify our message has been one of the main obstacles we have had to overcome.

There is an option for HOAs to complete a Firewise Program through the Department of Forestry and Fire Management.  This program is used to teach communities how to live with wildfire as well as how to protect themselves.  We found out that most Firewise-approved HOAs also mentioned invasive plant species in their CC&Rs.  This was an interesting discovery that led us to get in contact with the Firewise Program to figure out how HOAs could become Firewise-approved.  After conducting our interviews, we will be able to provide the Firewise Program a list of HOAs already interested in partnering with us that may also be interested in becoming Firewise-approved.  This could help streamline their approval process.

Why is this important?

This project is important because it aims to create a bridge between two sectors (these being non-profits, such as ourselves, and HOAs) that have not really collaborated before while also focusing on an issue that is increasingly dangerous for our wildlife and our local communities.  Also, our deserts are slowly changing into dry grasslands with the help of the growing invasive plant species populations.  This is not only bad for our local ecosystems, but it also increases the threat of wildfires.  Limiting the growth of invasive plant species and removing them will help preserve our native landscape and keep our wildfire numbers in check.  Most importantly, this project looks to keep our deserts and our communities safe.

If you are interested in learning more about this project and our efforts, please feel free to reach out to Mary Fastiggi, the Parsons Field Institute Coordinator at the McDowell Sonoran Conservancy (, and/or Dr. Aireona Raschke, the Director of the Central Arizona Conservation Alliance (CAZCA) (  They are the main leaders for this project and have supervised over my work for the summer.

From My BackYard to Yours with Intern Paisley Longenbaugh

Did you know that some plants can actually harm the surrounding environment that they occupy? The presence of invasive plant species in Arizona has led to an increase in fire danger and severity, a decrease in native plant species populations, a decrease in biodiversity, and other negative impacts.

I am currently a student at Northern Arizona University studying environmental sciences and have been working as an intern with The Central Arizona Conservation Alliance (CAZCA) to study Homeowners Associations (HOAs) to determine how public entities can contribute to invasive plant species management. The long-term goal of this project is to eliminate harmful invasive plant species in communities to lower fire danger and severity, and create a healthier environment in the Phoenix-Metro area. This is important because many of these invasive plant species contribute to the rapid spread of fires and they contributed to several fires in 2020 that led to evacuations in the Phoenix-metro area. Buffelgrass (Pennisetum ciliare, Cenchrus ciliaris) is a good example of this, as we have plenty of science showing its impacts on fire in Arizona.

Buffelgrass is native to Africa, Asia, and the Middle East. It, along with other invasive plant species in Arizona causes more damage than just increased fire hazard. Buffelgrass has a strong presence and usually ends up taking over the habitat of native plants. This phenomenon leads to a decrease in biodiversity. Buffelgrass also burns at an average temperature of over 1000 degrees Fahrenheit, and it is fire adapted which means it has traits that help the plant survive wildfires or thrive after a wildfire has occurred. In contrast to buffelgrass and how it reacts to fire is saguaros, which will not survive a fire in the long term if burned more than 30%. This is a large problem in Arizona because saguaros are an iconic, culturally-important native species. Overall, the species is a threat to the ecosystem, community, and economy as the effects can leave expensive consequences.

I have been working with the help of Dr. Aireona Raschke (the program director from CAZCA) to gather information from Homeowners Associations (HOAs) across the Phoenix-metro area in order to see what type (if any) of invasive plant species regulations are being enforced within their communities. For the most part, this information comes from HOAs CC&Rs (Covenants, Conditions, and Restrictions) which are usually available to the public. We’ve found that many HOAs do not have restrictions regarding invasive plant species or a prohibited plant list that includes invasive species.

Why is this Important?

I think that it is important for HOAs to use their position in communities to help benefit the environmental state of the area. Conducting the research and seeing some of the restrictions that do exist makes the long-term goal of eliminating invasive plant species seem attainable. Although extraction of these plants takes work, enforcing restrictions would bring about a gradual change that would benefit many aspects of community.

At this stage in the project, available information from several HOAs across the Phoenix-metro area has been collected and a small number of HOAs have been selected by myself and the other intern to begin outreach. We plan to interview members from each selected HOA to get a better idea of their policies and possibly, with some time, work with them to implement new policies that contribute to the well-being of the environment overall.

What I’ve Learned

Working on this project has taught me a lot about invasive plant species as well as what kind of work is available in my area of interest and study. I have learned how to effectively communicate with public entities, gather information, build and manage databases, and all about environmental problems we face in Arizona. My research skills have improved and I am constantly improving my adaptability as my team and I adjusted our research plans to be 100% digital during the COVID-19 pandemic. Transferring some of the skills and knowledge I have obtained through school into a real project that has the potential to bring on long-term change has been very encouraging. This is an ongoing project so future interns/NAU students will work to accomplish long-term goals.


CAZCA is an initiative of Desert Botanical Garden. Any donations made to CAZCA must be made through Desert Botanical Garden. You will now be taken to their website to complete this transaction. Thank you!