Current global challenges require solutions that cannot be delivered by any one field alone. Our work bridges multiple disciplines to advance basic understanding and solve problems of ecological and societal significance. Recent projects can be divided in three main areas:
1- Understanding natural ecosystem dynamics and the legacy of past environments
The pursuit of solutions for current global challenges is in many ways synonymous with the search for historical knowledge to support theoretical and practical inquiry into sustainability. Indeed, every system that has persisted through time must have acquired some degree of resilience to environmental change. We use archives of past environmental conditions, such as tree rings, soil profiles, and speleothems, combined with measurements of stable isotopes, elemental analyses and radiometric dating to elucidate how environmental change has impacted terrestrial systems before and after humans became a dominant planetary force. Our studies focus on describing the influence of past environments on the distribution of modern biomes, providing valuable information to understand the forces that shaped ancient and contemporary societies.
2- Quantifying the impact of human-induced changes in climate and atmospheric composition on managed and natural ecosystems
Since the industrial revolution, the human influence on the global environment has become so large that a case has been made for a new geological epoch: the Anthropocene. Using observation and experimental datasets, which integrate physiological, biogeochemical, and ecological methods, we investigate the impacts of rising carbon dioxide levels, nitrogen deposition and shifting edaphic properties on the performance of individual species and functioning of entire ecosystems. Long-term responses measured in natural ecosystems serve as a baseline to predict responses in managed lands responsible for energy and food production.
3- Developing management and restoration strategies to mitigate the impacts of global environmental change and optimize the use of natural resources
We study how complex soil-plant-atmosphere interactions control concerted changes in terrestrial carbon, water, and nutrient cycles can be harnessed to provide solutions for current environmental challenges. We combine information from ancient and contemporary settings to design conservation, management, and restoration efforts that that will improve the use of natural resources and the sustainability of managed and unmanaged lands. Recent projects test new methods to increase water use efficiency in orchards, restore plant diversity and promote carbon sequestration in mined lands and subsiding wetlands. Using baseline data from natural systems, we evaluate how managed forests, agricultural fields, and bioenergy crops can be used to enhance ecosystem services and promote climate stability.
National Science Foundation: Delineating Holocene climate-biosphere links from climate and vegetation reconstructions from the Amazon region
Water Sustainability and Climate (WSC) USDA-NIFA: Agricultural sensitivity to climate change and water resources interactions in the San Joaquin Valley California and system resilience offered by adaptation strategies
California Department of Food and Agriculture: Isotopic records of evapotranspiration, water balance, and depth of water uptake in California’s tree crops
University of California Innovative Development: Retracing drought impacts in California: A new approach to measure changes in food quality and productivity as caused by fluctuations in rainfall
Save-the-Redwoods League: Understanding the influence of an apex predator on the forest carbon cycle: mapping trophic pathways and identifying microbial players with stable isotope and community DNA analyses to uncover poorly known but significant trophic relationships with implications for global climate change
Recently completed grants
American Carbon Registry: Restoration of California Deltaic and Coastal Wetlands for Climate Change Mitigation
Chinese Academy of Science: Climate-driven vegetation dynamics across altitudinal gradients in the Qinghai-Tibetan Plateau, China
UC MEXUS-CONACYT: Effects of soil-plant feedbacks on the response of forest ecosystems to climate variability and nitrogen deposition
National Council for Scientific and Technological Development: Ecological implications of large scale restoration of degraded land in the Cerrado-Amazon transition
We work collaboratively across biomes to understand causes and mitigate consequences of ecosystem transformations. The map below displays the location of scientists who co-authored peer-reviewed articles with professor Lucas Silva’s (SPA Lab – Principal Investigator). Source: ISI Web of Science.