My research
I am motivated by applied research questions – how can we make ecosystems deliver benefits for society, while also conserving biodiversity?
To answer such questions, we need to first understand how ecosystems work. I start from ecological theory and first-principles thinking to come up with ideas. Then, using outdoor field studies, lab measurements, and modeling, I put these ideas to the test.
Current Projects
I am also studying how grassland fire hazard might change over time due to a warming climate and ecosystem change.
My work is part of a larger project led by Dr. Jonathan Henn, see the full project website here:
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.
I am investigating which grassland types present the highest fire hazard and which interventions might be effective to reduce this threat. I am particularly interested in understanding possible trade-offs between fire hazard reduction and grassland ecosystem services (the benefits provided by grasslands to people).
Additionally – together with Sam Ahler, Tom Merchant, and Jonathan Henn at CU Boulder – I am investigating the flammability of grassland plant species in the Front Range. Some, like the large bunchgrass on the left, may promote fire by having a large, well-aerated structure. Others may be more dense and less flammable (right).
This information might help us identify which species local agencies can promote to reduce grassland fire hazard.
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?
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!
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.
This research can help us identify which species are ideal to promote in grasslands in order to maximize forage availability.
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.
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.