Monday, October 9, 2017

Graduate Student Fall Update


Britt Smith
A large wildfire south of Sundown, TX occurred on February 28, 2017. This wildfire occurred in a sand shinnery oak community comprised of shin oak, honey mesquite, blue grama grass, and western ragweed. Immediately after the fire the landscape is charred and black. Shin oak is a fire adapted plant with a vast root network, and begins to grow immediately after fire. Many of the grasses and forb plants are also fire adapted, and with adequate rain fall begin to emerge from seed or regrow from protected tissues. In the left half of the image below, taken on June 15th, we see the resprouting shin oak dominating the vegetation cover with small ragweed seedlings in the foreground. The image on the right was taken over three months later, on October 3rd, and we can see that the ragweed nearly matches the ground cover area of the shin oak with many grass species having set seed. Sand shinnery oak communities are highly adapted to fire. Even within a single season we can see the community responding to a disturbance that keeps the vegetation short; a pattern that has shaped the Southern High Plains for thousands of years.





Neil Estes
My second summer of fieldwork and exploration in the Valles Caldera went really well. I am pleased with the efficiency of my work from dodging local weather to navigating the fallen timber in the burn zones on my way to remote points. I meet all of my goals and objectives. I am now in the analysis phase with respect to my data and look forward to seeing some results. 




Jonathan Knudsen
I've spent the past two years staring down a microscope sorting, counting and identifying ants.  Currently, I oversee four undergraduates, who have been invaluable in helping me get through all the work.  So far we've counted over 45,000 individual ants and have identified around 50 different species, including some rather cryptic and interesting species.  I have recently finished some field work in the Valles Caldera, where I was processing logs and conducting leaf litter sampling. 




Heather Williams
My final field season wrapped up at the end of August. My technician, Scott Hill, and I were based out of the TTU Junction Center for three months where we worked on the river by day, and lab by night. It was a very successful field season for collection of Guadalupe Bass! I also had an opportunity in September to assist with the final mark-recapture event for Blue Sucker on the Colorado River, Texas. It is always an honor to work with this state threatened fish. Having worked closely with this project under PhD student Matthew Acre since it's establishment in December 2014, it was great to see the field work to it's end. Finally back in town and back to a normal schedule. 

Friday, March 3, 2017

Heather Williams-- the fish girl in the fire lab!


Hello. My name is Heather Williams and I am a graduate student in the TTU fire ecology lab, with a focus on aquatic sciences – “the fish girl in the fire lab”! Dr. Verble graciously took over as lead advisor on my project in June 2016 after my PI, Tim Grabowski, took on an exciting job opportunity to lead the Hawai’i Cooperative Fishery Research Unit in Hilo. Dr. Verble was an important mentor for me during my undergraduate career at Texas Tech and I am so pleased to have her overseeing my project. She is teaching me how to be a scientist, and hopefully I can teach her a little about fish.


My research focuses on flow ecology of Guadalupe Bass throughout their native range. Guadalupe Bass is the official freshwater state fish and endemic to regions of the Edwards Plateau in central Texas. Adapted to riffle-run habitat with higher-current velocities, this species is considered to be flow dependent, requiring a relatively undisturbed mosaic of stream habitat in order to persist. This habitat need is threatened by our ever increasing water demand, and the Guadalupe Bass range is home to some of the fastest growing urban centers in the country. However, the influence of flow regime on growth, recruitment, and mortality of this species is not well known. So the objective of my study is to evaluate these relationships in order to develop instream flow recommendations to benefit both Guadalupe Bass as well as other flow-dependent species.


Flow-growth relationships are determined through examination of a fish’s otolith. Much like tree-ring dating, fish also have hard structures which can be used to determine age and growth. Otoliths are calcium carbonate structures in the inner ear that aid in balance and movement for all vertebrates. (Yes, you have otoliths too!) Counting the annual growth rings (annuli) on otoliths is a common technique for estimating age of fish. Annuli are reflective of seasonal growth patterns – fish grow faster in the summer than in the winter. Thus summer zones are wide and translucent while zones representing winter growth are narrow and opaque. This data is then used to reconstruct year classes and estimate mean growth rates related to flow conditions.

I am currently staying really busy, processing our age data and gearing up to sample more river sites throughout the Texas Hill Country. An additional benefit of being a student in the fire ecology lab is that I have the opportunity to stay up to date on my NWCG certifications and continue volunteering on prescribed burns in the region. Here is a photo of Michael Tynes and myself on a burn at the Rolling Plains Quail Research Center. It was a great day!