Collaborative Research: IntBio: Defining the mechanisms and consequences of mutualism reorganization in the Anthropocene.

No organism lives in isolation. Instead, life is a web of beneficial and costly interactions among organisms and the environment. Yet little is known about how these connections will shift with global change.

By the end of the 21st century, climate change will increase mean annual temperatures and shift precipitation patterns. At the same time, invasive species will cover at least 17% of Earth’s land surface, including most of North America. Plant associations with microorganisms belowground are one of the most widespread mutualisms on the planet.

These mutualisms are also particularly sensitive to global change. However, the mechanisms underlying how plant-fungal mutualisms will withstand and adjust to new environments are still unclear. Thus, the key question remains: How will mutualistic partners reorganize and affect mutualism function in the future?

Answering this question requires integrative, multi-disciplinary research across scales and systems. This work will create these synergies by tracking organismal, physiological, population, and community responses of native plants and their beneficial and disease-causing fungi to an invasive plant, Alliaria petiolata (garlic mustard). The project will have educational impact for a next-generation STEM workforce by providing integrative research and training experiences for undergraduate students from diverse backgrounds.

This IntBio project builds on a long-term experiment of exotic plant invasion to address four AIMS. I: Determine long-term patterns of arbuscular mycorrhizal (AM) and pathogenic fungal communities associated with native plant species and how fungal communities are reorganized by invasion. II: Determine how reorganization of plant-AM fungal mutualisms affects plant physiology including carbon fixation and nitrogen uptake.

III: Determine the extent to which reorganization of plant-AM fungal mutualisms and/or soil nutrient availability alter plant growth, survival and reproduction. Experimentally addressing these aims will allow IV: Integration of the results from the first three AIMs to scale from mutualism reorganization to plant physiology, to plant population and community demography.

The research is integrated across different scales (spatial, temporal, levels of biological organization). It will generate novel insights that will be broadly generalizable to mutualism reorganization that is likely occurring under in other global change scenarios. This research is grounded in “photosynthetic least cost theory.” The overarching prediction is that if belowground mutualism reorganization makes nutrient acquisition more costly for the plant in terms of its carbon use, then significant shifts in plant physiology will be observed.

This project will be the first to explore integrative, untested, and potentially transformative ideas surrounding the reorganization of mutualistic interactions in the Anthropocene. This team bridges Texas Tech University, a Hispanic Serving Institution, and the University of Tennessee, Knoxville, which serves students from Appalachia. Undergraduate students from Hispanic or Appalachian families share a common web of socio-cultural, financial, and academic barriers related to success in college.

The training component aims both to enrich undergraduate students’ experiences through integrative research and to enhance such 1st generation students’ success through financial, mentoring and training support, and opportunities for students and their families.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.