Linking plant evolution with soil microbial processes in coastal marshes

Coastal marshes are among the most productive ecosystems on Earth, providing valuable services that are increasingly threatened by human-induced environmental change. Anthropogenic pressures can negatively impact constitutive biota, like coastal vegetation and soil microorganisms capable of governing ecosystem processes such as biogeochemical cycling that determine the availability of valuable services (e.g., storm protection). Despite its potential importance, efforts to forecast the state and fate of coastal marshes thus far rarely account for the impact that climate stressors may have on plant-microbe interactions. We are investigating how soil microbial processes (e.g., functional diversity) are influenced by plant evolution (i.e., genetically based trait variations) under conditions of environmental change. Leveraging 100+ year old seed banks of Schoenoplectus americanus, we are examining if differences in plant traits arising from different genetic identities of an ecologically-important salt marsh plant contribute to differences in soil microbial processes under the interactive effects of elevated nitrogen and salinity.

                             

                              Germinating 100-year old Schoenoplectus americanus seed collected from marshes

Ecological drivers of plant-microbe interactions in wetlands

                                                     

Wetland ecosystems provide critical and important functions such as organic matter decomposition and nutrient cycling. Soil and endophytic (microbes inside plant tissues) microbial communities can regulate these functions. Yet, our understanding of the processes underlying the assembly and functions of these microbial communities remains limited. I examine the relative influences of a suite of biotic and abiotic factors on the distribution, diversity and structure of fungal and bacterial communities within the rhizosphere, root and leaf endosphere in wetland plant species: Batis maritima, Taxodium distichium and Spartina alterniflora.

Plant-Microbe-Contaminant Interactions

Environmental pollution is a major concern along the Gulf of Mexico. We aim to study the different levels of responses (flipside: levels of impacts) of oil and heavy metal pollution on soil microbes and coastal plants. This project is partly funded by the AAUW Publication Research Grant and by TAMU-CC Research Enhancement Grant.

                                                       

 

Endophyte fitness and stress tolerance

This project aims to assess endophyte fitness and tolerance to environmental stressors including salinity and oil and heavy metal contaminants. We use traditional culture assay approaches on endophytes we have isolated from marsh plants and genetically identified.

                                                  

 

Mycorrhizal biodiversity in the gulf coastal prairies and marshes on barrier islands in South Texas

The gulf coast prairie dunes and marsh ecoregion in South Texas is an understudied region, particularly in the field of fungal ecology. The coastal dune ecosystems defining the barrier island ‘chains’ in South Texas along the northern Gulf of Mexico provides many important ecosystem services such as wildlife habitat, flood prevention and serves as the first line of defense against hurricanes and sea level rise. Yet they are at-risk ecosystems as many of these areas have been lost to human activities over the years and to natural and anthropogenic degradation including oil pollution. Despite the importance of these coastal dune mycobiomes and specifically, mycorrhizal communities, they have been largely unexplored. Without the basic understanding of the nature and tempo of these mycobiomes as they respond to their natural environment, it is challenging to have a better and accurate prediction of how much diversity is lost or being lost due to environmental changes, and the ecosystem-level and ecological consequences of such loss. This project aims to provide basic information on the distribution and diversity patterns of soil mycobiomes in the region. Insights gained from the proposed study can also help inform coastal management and conservation and aid in nature-based solutions for rehabilitating some of these barrier island habitats – for example, AMF-assisted belowground growth of coastal plants. This project is funded by the Society for the Protection of Underground Network (SPUN) https://www.spun.earth/.