Eviner Lab

Focal Research:

The following topics are addressed through a range of projects that improve our understanding and management of invasions, restoration, ecosystem services, species conservation, global change, and range management.

1. Effects of plant community composition on ecosystem processes and properties.

Plants not only respond to their environment, they can actively alter almost every aspect of ecosystem structure and function. We are particularly interested in understanding their effects on soil processes that mediate nutrient, carbon and water dynamics. We seek a mechanistic understanding of:

1. The effects of multiple plant traits on multiple ecosystem processes.
2. How plant species effects change across sites, environmental conditions, management practices, and time
3. The effects of mixed-species communities. These effects often cannot be predicted based on the effects of the component species in monoculture. We are investigating how species effects change depending on the identity, density, and diversity of neighboring species.
4. How plant communities impact other key organisms, which are important players in mediating ecosystem processes (e.g. gophers, voles, microbes, livestock).

2. Controls over ecosystem resilience under changing conditions.

Many ecosystems are experiencing conditions that are changing and novel. We are assessing the foundational processes that provide resilience to California's ecosystems due to climate change, drought, fire, invasion, and land use change. This includes assessing the impacts of plant diversity, key plant species, seed banks, and soil carbon and water holding capacity on ecosystem resilience, and how we can enhance resilience through land stewardship.

3. Feedbacks: How plant effects on soils alter plant community interactions. How environmental changes shift vegetation composition, leading to a further changes in the environment.

Long-term management of vegetation composition and ecosystem processes requires an in-depth understanding of their interactions. For example, if invaders alter soil to benefit themselves, successful restoration of native vegetation may require soil amendments. Similarly, direct effects of global changes on ecosystem processes may be small, or opposite in direction, compared to the effects mediated by shifts in plant composition.

1. To what extent do plant effects on soils mediate community interactions?
2. How do the strength and nature of feedbacks change over time and environmental conditions?
3. Which aspects of plant effects on soils are most important in shaping community interactions? How does this change over space and time?
4. How long do species effects on soil last after the species have been replaced? To what extent does this depend on how long the species was present? Which feedbacks have a strong legacy?

4. Ecological toolbox for sustainable ecosystem stewardship.

We actively collaborate with a diversity of land managers in our research. Not only does this allow us to apply our research to real-world situations, but it also provides unique research opportunities for understanding complex systems. By trying to reliably manage for specific goals, we are constantly aware of short-comings in our ecological theory. The previous three research topics are synthesized in our efforts to develop better management practices based on our latest results. We are particularly involved in: invasive species control, conservation and restoration of native and rare species, and management for ecosystem services (e.g. control over erosion, water quality, soil fertility, carbon sequestration, water storage and flow).

1. What are the most effective ways to reliably manage for target plant communities, and/or multiple ecosystem services?
2. How do these management strategies change over space, time, and shifting environmental conditions?

Research Approach:

While individual research projects fall everywhere along the applied to theoretical spectrum, most of the lab’s research is based on the premise that we can simultaneously address cutting-edge conceptual questions and applied issues. We work closely with land managers to: (1) Identify theoretical gaps that are critical for management, and (2) Use ecosystem management as the ultimate test of how well we understand complex ecosystems.

Most projects use a suite of research approaches, including: experimental manipulations in the field, greenhouse and growth chambers; field observations and natural history; and working with land managers to use their management as long-term manipulative experiments to test ecological interactions over time and space.