My research
I am motivated by a key question – how can we make ecosystems deliver benefits for society, while also conserving biodiversity?
To answer this big question, we need a combination of theoretical advancement and applied research. To manage ecosystems, understanding how nature works is critical. Theory provides wealth of knowledge from which to develop hypotheses, so I start from there. Then, using field studies, lab measurements, and modeling, I put my ideas to the test.
Current Projects
Fire hazard in Colorado’s Front Range Grasslands
Grassland wildfires pose a severe threat to life and property in Colorado, the American West, and beyond. Together with an amazing team of researchers across several institutions, and in collaboration with land managers, I am investigating the drivers of grassland flammability and intervention options to reduce fire risk.
We thank the City of Boulder Open Space & Mountain Parks Department, Boulder County Parks & Open Space, the U.S. Joint Fire Science Program and others for supporting this project.
Understanding and predicting grassland fuel loads
As part of a team of researchers led by PIs Jonathan Henn at the University of Illinois and Katharine Suding at CU Boulder, I am assessing the drivers of grassland fuel load from topographic, hydrologic, and edaphic drivers of grassland productivity to species composition.
We are also developing models trained on field data to predict grassland fuel loads from remotely-sensed imagery. This work, led by Dr. Lina Aoyama, was recently published in Fire Ecology. Read our publication here!
Flammability traits
Together with Sam Ahler, Tom Merchant,, Jonathan Henn, and Katharine Suding at CU Boulder – I am investigating the flammability-related traits of grassland plant species in the Front Range. We are investigating how the overall structure, moisture content, and tissue properties of plants influence their propensity to burn.
Scaling from species traits to decomposition and flammability
Species traits should relate to decomposition, which controls the accumulation of surface fuel, and to the fire behavior that fuel produces when it burns. But which traits (structural, chemical, morphological) drive the decomposition rate of the litter produced by a species? Which traits control the flammability properties of a species’ litter (total heat release, rate of combustion, ignitability)? Further, are there emergent properties – unique effects that happen when species grow together?
My study seeks answers to these questions. This knowledge could not only help us understand how plants influence fire regimes more generally, but also help us choose species to include in ecological restoration and urban gardening.
Fuel treatment efficacy
Together with land managers in Boulder, I am studying the efficacy of grassland fuel treatments – mowing, prescribed burning, and grazing – in reducing fire risk. We’re also assessing the durability of fuel treatments: how long after application before a grassland can carry fire again?
Finding the right tree species to cool our cities
Urban trees reduce temperatures in urban areas, making urban forests a promising nature-based solution to cool cities that are warming to dangerous levels due to climate change. A crucial question in choosing what trees to plant is: do some tree species provide more cooling than others?
This project was featured on INSTAAR news, see the article here!
I am studying which tree species provide the greatest heat reduction in the urban environment and what traits might be underlying this power, such as canopy structure and leaf properties. This work can help us select tree species to plant in city tree planting programs.
This project is part of a collaboration with the City of Boulder Climate Initiatives Team and other researchers at CU Boulder. See the website for our larger collaboration here!
I thank the Garden Club of America, and CU Undergraduate Research Opportunities Program, and the City of Boulder Climate Initiatives Department for supporting this project.
If you are studying urban forest impacts on temperature, I would be excited to connect to share lessons learned and ideas for future work. Additionally, if the urban temperature and soil moisture data we collect in this study could be useful for your research (e.g., for modeling), please reach out!
Plant traits and the sensitivity of grassland production
Grassland productivity (the amount of growth that occurs in a year) is known to be sensitive to variable precipitation. Interestingly, different grassland types have varying amounts of sensitivity, which leads to the question – why? One possible answer is that each plant species has a different level of sensitivity to precipitation based on its distinct traits.
Through a greenhouse experiment, I am investigating which plant traits control the sensitivity of grassland productivity to precipitation. I am looking at the traits of leaves and stems, as well as roots, to understand sensitivity.
Past Projects
Plant traits in the design of nature-based solutions
Nature-based solutions expand on the concept of ecological restoration to prioritize economic development and human values. However, the science needed to effectively plan, monitor, and validate nature-based solutions is still in its early stages. One gap in the science of nature-based solutions is our knowledge of how plant species functional traits – the unique, measurable properties of plants – contribute to ecosystem functioning, which then provides benefits to society in the form of ecosystem services.
To help fill this gap, my collaborators and I at CU Boulder proposed a framework for the integration of plant functional traits into nature-based solutions. We outline a research agenda for how functional trait information can be used in different types of nature-based solution projects, from conservation to the design of novel ecosystems.
Thatch removal and restoration of plant biodiversity
Thatch produced by invasive grasses (also called grass “litter”) can negatively impact native species. While thatch removal is a potential intervention to restore biodiversity, its effectiveness is not well understood.
I lead a study with colleagues at UC Riverside in which we conducted an experiment to test the effectiveness of thatch removal. We found that plant communities receiving thatch removal treatment had more native wildflowers, but also more invasive forbs (non-native wildflowers). This suggests there is a potential trade-off between controlling exotic grass invaders and controlling exotic forb invaders.
Overall, our findings suggest that if land managers want to increase plant biodiversity in California coastal sage scrub and grassland ecosystems, thatch removal can be an effective intervention.
We thank the Sea & Sage Chapter of the Audubon Society for supporting this project.
Tree seedling demography in Southern California mixed-conifer forest
At the Spasojevic Lab at UC Riverside, I studied tree seedling recruitment (growth and survival) at a forest dynamics plot in the San Jacinto Mountains of Southern California, USA. We surveyed seedling plots for 2 years to assess growth and survival rates. The lab will continue to monitor seedling demography at this site in upcoming years.
From this data, we found that adult tree communities are structured by different drivers than tree seedling communities. We also found evidence that adult trees might be modifying the environment in ways that influence seedling composition.