Team

Event, Sept 2016

Ajinkya Deshpande, PhD StudentAlinkyaDeshpande

Major: Ecosystem Science and Management

Education: MS in Environmental Science, University of Baroda, India; BS in Chemistry, Gujarat University, Ahmedabad, India

Professional Interests: I am primarily interested in studying the impacts of natural and anthropogenic disturbance on the ecological functions of forest ecosystems. Through my research, I am curious to answer questions on how the contemporary environmental changes are altering ecological processes in forest ecosystems and how the biotic components are responding to this rapid change. My MS Thesis was focused on assessing the status of the natural regeneration of an important timber species in India, Shorea robusta in the protected and unprotected forests of Doon Valley in the Lower Himalayas. My current research work is a part of the Texas Water Observatory Project. I am focusing on the effects of CO2 pollution and recent hydroclimatic anomalies on the bottomland hardwood forests in Southern Texas. I will be using dendrochronology and carbon and nitrogen isotope analysis as my prime research tools.

Aline Jaimes, Postdoctoral Research Associate

Education: PhD in Environmental Science and Engineering, University of Texas, El Paso; MS from Northwest Center of Biological Research (CIBnor), La Pas, Mexico; BS in Biology, University of Veracruz, Mexico

Professional Interests: I am an environmental biophysicist with experience in biosphere-atmosphere interactions. My field focuses on studying carbon, water, and energy balance in ecosystems undergoing environmental change. I am interested in interoperability of systems to facilitate data assimilation in environmental monitoring to support decision-making. Among my research interest are structuring networks of people to build and sustain human networks, learning the science of team science through pedagogy, organizational structure, and leadership training.

Paul Klockow, PhD StudentPaul Klockow

Major: Ecosystem Science and Management

Education: MS in Natural Resources Science and Management, University of Minnesota; BS in Agricultural and Biological Engineering, Purdue University

Professional Interests: I am interested in using technical and novel methods to better understand forest processes and the impacts of disturbance for informing forest management practices. My current work involves understanding interactions of drought and stand structure on tree mortality as well as coarse woody debris dynamics in loblolly pine forests of East Texas. Specifically, I am exploring Bayesian analysis techniques as well as using remote sensing applications to improve biomass estimation of decaying trees. My Master’s research focused on assessing impacts of harvest intensity on woody debris and nutrient retention in aspen forests of the Upper Midwest.

Luiza Maria Teophilo Aparecido, PhD CandidateLuizaAparecido

Major: Ecosystem Science and Management

Education: MSc in Tropical Forest Sciences at the National Institute of Amazonian Research (INPA: Manaus-Brazil)

Professional Interests: I always hope to learn more and more about plant function and growth. My background (undergraduate and master’s) was focused on forest inventory and management, with highlights in forest stand yields and tree allometry using mathematical equations. Also, I integrated these subjects to my master thesis with ecophysiology while studying about sapwood area determination and restrictions in a primary evergreen Amazon trees and palms. My hypothesis were answered analyzing and relating sapwood area with tree size, ecology succesions and wood anatomy. Now with my PhD, I hope to understand how a high-altitude tropical forest situated on a mountain side in Costa Rica can function under constant rainstorms, with low radiation and severe winds. To answer this question, I’ll rely on sap flow measurements to estimate transpiration and climatological data from a 40 meter high tower. All of these subjects since my undergraduate to my PhD is helping me construct my desired Forest Ecologist self-title.

Caitlyn Cooper, PhD Candidate

CaitlynCooperMajor: Agronomy

Education: M.S. Agriculture (agronomy emphasis), Tarleton State University, Stephenville, TX

Professional Interests: I have a broad interest in native plant restoration with particular focus on plant physiology of native prairie grasses and forbes. My PhD research will focus on using native plants to restore ecosystems following strip mining for lignite. My MS thesis research was entitled “Protein Precipitable Phenolic and Nutrient Concentrations in Legumes Respond Differently to Repeated Defoliation and Ontogeny”.

 Past Team

 Amelia Min-Venditti, MS StudentAmeliaMinVenditti

Major: Ecosystem Science and Management

Education: BS in Ecology & Evolutionary Biology and Hispanic Studies, Rice University

Professional Interests: Amelia Min-Venditti’s MS degree was earned under the guidance of Dr. Georgianne Moore and Dr. Forrest Fleischman. Her research is at the nexus of natural resource policy and ecohydrology. Through her thesis work, Amelia studied the effects of policy on tropical deforestation and the subsequent impacts of deforestation on the water budget.

Rosaleen March, PhD Fellow

Major: Forestry

RosaleenEducation:  M.S. Biology, Texas A&M University-Corpus Christi; Master of Marine Resources Management, Texas A&M University-Galveston;
B.A. Environmental Studies, Oberlin College

Professional Interests: I am interested in how the recent extreme droughts in Texas are affecting the landscape. The Texas Forest Service has estimated that approximately 500 million trees have died in 2011 alone due to the drought. My goal will be to quantify a more precise estimate by using remote sensing, and also quantify drought-related mortality during the past decade of drought conditions. I am also interested in how landscape features interact with species composition and mortality. I’d like to see how drought changes landscape pattern and what makes certain parts of the landscape more vulnerable to extreme drought than others. For example, are species on bottomland sites more vulnerable than those on the uplands? For these questions I will look specifically at the Edwards Plateau. Lastly, to broaden the perspective of ecosystem dynamics of drought, I’d like to look at drought mortality effects on wildlife. For now, the idea is to examine keystone species that range from specialist to generalist and develop a scenario for each.

Ingrid Karklins, Undergraduate Research Fellow

Major: Ecological RestorationIngridKarklins

Professional Interests: Post-fire and drought response of understory bryophytes versus vascular plants in the Lost Pines Ecosystem of Central Texas. While much attention has been focused on loblolly pine regeneration following the Bastrop Fires of 2011, few, if any, studies have considered the effects of fire and drought on regional understory species diversity.  There is no evidence that any research has included the non-vascular bryophytes, which are usually first-responders after fire disturbance.  This proposed study will survey the herbaceous and non-vascular plants in riparian zones and uplands of the unique Bastrop Lost Pines ecosystem, noting plant assemblage patterns in response to drought and fire that have developed three years after the fires.  The study will hopefully incorporate more recently burned areas, unburned areas, and areas burned prior to 2011.  If successful, there will be identifiable vascular plant and bryophyte associations and assemblages correlated to soil moisture content and fire intensity. Inferences may be possible regarding facilitation or competition between bryophytes and vascular plants in response to climate change.

Qihua He, Visiting Scholar

Major: ForestryQihuaHe

Education: Masters Degree in Botany (2003), Chengdu Institute of Biology, Chinese Academy of Sciences; Bachelor Degree of biological education (1996), Xuzhou Normal University, China.

Professional Interests: My research has focused on dynamics of soil moisture and microclimate in upper reaches of Minjiang River (China) for more than ten years (2000-present), and I am interested in field observation of ecohydrology and forest microclimate, as well as impact of seasonal drought to forest soil moisture; impact of different size forest gaps to forest soil moisture; interception and distribution effects of forest on Precipitation; microclimate characters of dry valley and conifer forest communities.

Jean Devlin, Masters student

JeanDevlinMajor: Rangeland Ecology and Management

Education: B.S. Ecological Restoration (minor in Forest Science) Texas A&M University

Professional Interests: I am interested in observing how wetlands are evolving to adapt and filter out increased nutrient and pollutant loads from urban regions experiencing rapid expansion. Wetland regions, such as the ones that exist within Houston, Texas, must tolerate greater amounts of nutrients and pollutants contained within urban storm water runoff. Initiatives to maintain and restore degraded wetlands within this region are currently underway. I am also interested in how the infiltration rate of the soils within the “lost pines” ecoregion near Bastrop has changed as a result of fire as well as the fires’ effect on the watershed. The extreme fire that burned thousands of acres of loblolly pine trees, destroyed much of the vegetation and exposed the soil. Given the extreme drought conditions Texas has experienced for the past few years, fire stricken areas are more vulnerable to erosion. I anticipate that portions of the Colorado River, as well as many other rivers within Texas, are likely carrying an increased sediment load, leading to negative impacts on habitat downstream.

Deseri Nally, Undergraduate Research Fellow

Major: Ecological RestorationDeseriNally

Response of wetland soils to flow alterations in the Sabine River below Toledo Bend Dam for the Texas Instream Flows Program: Given the known alteration in flood pulses into wetlands below Toledo Bend Dam, my study addresses how this loss of flood pulses is affecting the floodplain soils that are vital to riparian vegetation. If altered hydrology has changed sediment delivery, and the length of time soils are saturated, I expect zones of the wetlands to transition from hydric to non-wetland soils, especially in locations that are topographically high. Soil samples should be able to show hydric to non-hydric transitions in specific zones (e.g. sloughs, levees, and floodplains). Hydric soils are indicated by mottles of anoxic and oxidized patches. Studies have shown that soils have a high pH and decrease in pH as they become more oxidized (Wharton 1982). This property of pH will help serve as an indicator for soil oxygenation that have increased following the construction of Toledo Bend Dam.

Fan Li, MS Student

FanLiMajor: Rangeland Ecology and Management

Because Arundo donax has invaded the southern half of the United States, it is important to understand what mechanisms enable it to be such an effective competitor in riparian habitats. Fan Li’s study seeks to determine the effect of Arundo on the interaction between the river and groundwater: If it’s a losing reach, the presence of Arundo may cause less river water to recharge the groundwater. If it’s a gaining reach, groundwater that should flow into the river may be intercepted by Arundo.

Fan Li’s research questions are: (1) Does Arundo use groundwater as one water resource? (2) What’s the fraction of transpired water contributed by groundwater, precipitation, and river water? (3) Which method best estimates the consumption of water by Arundo?, and (4) How much groundwater is exchanged into or out of the river every day, and does the presence of Arundo impact the groundwater flux?

 

Blake Alldredge, Masters Student

Major: Water Management and Hydrological Sciences

Sabine_BlakeSabine River Instream Flows Project: The basis for our study rested on two main questions: “Has Toledo Bend Dam reduced flooding downstream?” and “What is the condition of the vegetative communities in the floodplains along the Sabine River?”  The question in reference to reduced flooding is essential to understand because of the role that hydrology plays as the “master variable” of ecological communities.  There is no historical vegetation data for Sabine River floodplains, rather, research findings gathered from vegetation plots in this study convey a “snapshot” of the community composition at the present time.  Information obtained from the literature can also lead us to understand what vegetative communities would be in a healthy floodplain of the Southeast U.S.

 

Li Kui, MS Student

Li_LiCorMajor: Rangeland Ecology and Management

Education: B.S. in Chemical Engineering and a M.S. in Environmental Science in Sichuan University, China.

Background: In 2006, she was involved in an international ecological restoration program in EarthCorps, Seattle, Washington. Later, she developed projects focused on invasive species control around Chengdu, China. She was previously executive director of the Green Student Organizations Society, which helps youth environmental activists to develop their environmental protection projects all over Southwest China. Li Kui also wrote a textbook on environmental education for middle school students of Chongqing, China.

Li Kui’s MS research is focused on the ecohydrology and distribution of giant reed (Arundo donax) in the Rio Grande valley. Project includes measurements of plant transpiration, soil moisture, stable isotopes, plot density, biomass and plant height in order to estimate the water use and distribution of the plant, by using such instruments as the LI-COR 6400, Diviner 2000 and a Thermo Delta V Isotope Ratio Mass Spectrometer.

Jose Franco, PhD Student

JoseFrancosmEducation: M.S. Range Science, New Mexico State University, 2007. B.S. Biology/Geology, The University of Texas at El Paso, Cum Laude 2004
Hometown: El Paso, Texas
Thesis Topic: The influence of vegetation, soils, and topography on runoff dynamics and E. coli loading in a karstic system of central Texas.

 

David Watts, MS

DavidWattsThesis: Dynamics of Water Use and Responses to Herbivory in the Invasive Reed, Arundo donax (L.). (May 2009)

Abstract: The first objective of this study was to investigate the role of an invasive grass
species, Arundo donax (L.), on the hydrologic cycle. At a site on the Rio Grande in
South Texas, we measured the gas exchange of carbon dioxide and water vapor at the
leaf scale and structural characteristics, such as leaf area and shoot density, at the stand
scale. In order to assess the effect of water availability, this study was conducted along
transects perpendicular to the edge of the river along a potential moisture gradient. The
second objective was to quantify the effect of two herbivores, an armored scale,
Rhizaspidiotus donacis (Leonardi), and a stem-galling wasp, Tetramesa romana
(Walker),on the photosynthetic and transpiration rates of A. donax. Leaf gas exchange measurements were made to determine the direction and magnitude of the effect on physiological processes and by what mechanisms any effects arose. Stands of A. donax used approximately 9.1 ± 1.1 mm of water per day. This rate of water use was at the high end of the spectrum for plants. The major controls on stand scale transpiration were evaporative demand, leaf area index, and water availability. During two summer seasons, stand scale transpiration varied greatly, following the pattern of variability in precipitation, suggesting that recent rainfall constituted a significant proportion of the water taken up by this species.

Herbivory by a stem-galling wasp and a sap-feeding scale, both separately and together, reduced the rates of leaf scale physiological processes in A. donax. The efficacy of the wasp was density dependent, and this herbivore reduced the carboxylation rate of Rubisco. The effect of the scale took approximately five months to manifest, which coincided with generation time. Scale reduced photosynthesis by decreasing the maximum rate of electron transport. When the two insects were both present, the effect of their herbivory seemed to be additive. These results will assist the responsible management agencies in evaluating the propriety of using one or both of the insect herbivores as biological control agents.

 

Dave Barre, MS

DaveBarreThesis: Long-term hydrologic responses to shrub removal in a SW Texas rangeland: Using soil chloride to estimate deep drainage. (August 2009)

Abstract: The Carrizo-Wilcox aquifer is a valuable groundwater resource, situated in a semi-arid landscape of Southwest Texas, where over-use by dependent farming practices has lowered aquifer levels. In semi-arid regions, rates of groundwater recharge are predominantly low due to high potential evapotranspiration rates; however, least understood is the role that vegetation plays in soil-plant-water dynamics. Vegetation
management potentially plays a major role in countering the loss to recharge because evapotranspiration (ET) varies with vegetation type and cover. The conversion from shrubland to grassland likely reduces rooting depths and total plant cover. Subsequently, deep drainage (percolation below the root zone) will likely increase and lead to groundwater recharge, at least temporarily. The primary aims of the study were to identify those biotic and abiotic factors facilitating deep drainage and to examine differences in recharge for the years following clearing of natural shrub vegetation. Soil chloride was examined to estimate long-term recharge rates, since its concentration in the soil is influenced by the movement of water. Short-term soil moisture trends were also monitored for any water movement deep in the soil profile in response to individual rain events. Rooting depths decreased following removal of vegetation; yet root biomass unexpectedly increased due to successful grass establishment during the first five years after treatment. Soil properties did not vary between treatments, indicating that the majority of chloride differences seen were a consequence of vegetation change. Peak and total soil chloride concentrations were expected to decrease and occur deeper in the soil profile 15-30 years following the clearing of woody vegetation. Total chloride decreased by up to 65% after 30 years and resulted in an estimated 14.9 mm/yr more recharge compared to adjacent untreated controls. Evidence in this study suggest that much of this chloride is leached during the first five years following treatment and that more leaching occurs in especially wet periods. During the wet 2007 growing season, soil moisture below the root zone increased by up to 17% after vegetation clearing. The results of this study indicate that hydrologic changes following brush removal were evident in this system and are likely to positively influence groundwater recharge in the long-term.

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