Dr. Brad Hoge: Instructor of Biology and Geology

Dept. of Natural Sciences.

Research Interests: Wetland mitigation success.

Diatom and Arcellacean succession in mitigated wetlands.

Foraminera death assemblage formation.

Modeling of wetland response to salinity changes.

Possible Projects for Undergraduate Research:

1. Assessing wetland mitigation success through diatom and arcellacean community succession.

The Greens Bayou Wetlands Mitigation Bank has been established by the Harris County Flood Control District to provide wetland mitigation for projects in Harris County that destroy wetlands as part of their development. This is required by law, and is satisfied on an acre to acre basis, but how adequately the new, mitigated, wetlands replace the function of those destroyed is not fully known.

Diatom and arcellacean communities are good indicators of succession in wetland soils. Determining microbial community structure at the surface and at depth of various wetland soils can provide models of soil function, wetland succession and the success of mitigation efforts.

This past summer, two SA students, David Lang and Justin Varghese, performed research on diatom succession in the Greens Bayou Wetlands Mitigation Bank. They compared mitigated wetlands in the Greens Bayou Wetland Mitigation Bank with undisturbed wetlands within The Anahuac National Wildlife Refuge.

The Anahuac National Wildlife Refuge is a relatively undisturbed wetland. By comparing samples taken from areas within the Greens Bayou Wetlands Mitigation Bank and The Anahauc National Wildlife Refuge, we will be able to asses the state of mitigation efforts.

In the future I will be interested in various sites within the refuge, and in various taxonomic groups. I would like to study the taphonomy of diatoms in the mitigation bank to compare soil chemistry between the two sites. I would also like to do similar studies with arcellaceans. I also need to determine the source of diatoms and arcellaceans to the Mitigation Bank.

Finally, I would like to model the succession of diatoms and arcellaceans using STELLA.

2. Taphonomic modeling of wetland soils.

The use of microfossils as paleoindicators of wetland facies is limited by taphonomic processes. By combining multiple thanatocoenoses, however, it is possible to model facies transitions across fine time scales. This research will be an extension of my dissertation which established a model of taphonomic signatures in response to sea-level fluctuations

The first step I need to take to return to this modeling effort is to determine the composition of cements used by Foraminifera. Students will obtain samples, identify bio and thanatocoenoses in the laboratory, and perform chemical analyses.

This information will be used to model the taphonomy of foraminifera. By combining these taphonomic signatures with those of diatoms and arcellaceans, a model of sea-level change can be made. I will again use STELLA to produce this model.

3. Application of taphonomic models to the Paleobiology database.

The Paleobiology database is paleontology’s answer to the Human Genome Project. It is a large database of information on the origination, biogeography and extinction of marine species throughout geologic time. Analysis of the database will answer many questions about the history of life on earth and how we interpret it. I believe this is particularly exciting from a taphonomic perspective, since many of the hardest questions to answer in paleobiology relate to unconformities which may be elucidated by the application of taphonomic models. This will require extensive review of the database as well as the application of computer and statistical modeling.