Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Target Audience: Our target audience included a broad range of stakeholders at local, regional, state, national and international scales. We have communincated the importance of our findings to fellow academics and professional scientists at conferences, state and federal agency personnel, students in the classroom and outdoor field settings, and land owners and managers on their respective properties. Of the graduate students working on aspects of this project there are three women, two of who are Hispanic. These role models are tremendously valuable for the message of empowerment and inclusion they set for our stakeholders and future stakeholders (students and other young people) many of whom belong to various minority groups. Efforts: Our efforts have included peer-reviewed publications, presentations at professional conferences, formal classroom and laboratory education, extension agent and landowner engagement during field days, and meetings with state and federal agency personnel to discuss the potential impact of our findings. Changes/Problems: While the encroachment of Opuntia cacti continues to be a major focal area of our research efforts, we have broadened our ecological perspective to address multiple areas of problematic plant invasions, rangeland degradation, and the development of management strategies for landscape restoration. What opportunities for training and professional development has the project provided? These efforts have led to import professional development of graduate and undergraduate students as well as educational outreach to a broad diversity of local, regional, national, and international stakeholders. How have the results been disseminated to communities of interest? These results have been communicate through peer-reviewed publications, presentations at professional conferences, lectures in classroom and field settings, visits with stakeholders at field stations, and discussions with state and federal agency personnel. What do you plan to do during the next reporting period to accomplish the goals? I intend to continue to advance the primary objectives of my research team through training and educating students, presenting at professional conferences, giving lectures to students and other applicable participants in classroom and field settings, visiting with stakeholders at field stations, and discussing our findings with state and federal agency personnel.

Impacts
What was accomplished under these goals? We have continued to make progress on all of the goals stated above. My research laboratory continues to be internationally recognized for the scientific advances we have made in ecological science and for the potential applications of these findings to influence environmental management and ecological restoration.

Publications

• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Carissa L. Wonkka, Dirac Twidwell, Charles A. Taylor Jr. Chris B. Zou, Jeremiah J. Twidwell & William E. Rogers. 2013. Exceptional drought events cause patch-level patterns of woody dieback in semiarid Texas: comparing the 2000s to the 1950s. Abstracts, Society of Range Management Annual Meeting, Oklahoma City, OK.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Dirac Twidwell, Sam Fuhlendorf, William E. Rogers & Charles A. Taylor, Jr. 2013. Coupling fire physics and fire ecology to quantify state transitions and guide restoration actions. Abstracts, Society of Range Management Annual Meeting, Oklahoma City, OK.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Gabriela Sosa, William E. Rogers & Charles A. Taylor, Jr. 2013. Manipulating prolonged drought conditions on a prickly pear encroached rangeland. Abstracts, Society of Range Management Annual Meeting, Oklahoma City, OK.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Twidwell, Dirac, William E. Rogers, Samuel D. Fuhlendorf, Carissa L. Wonkka, David M. Engle, John R. Weir, Urs P. Kreuter, Charles A. Taylor, Jr. (2013) The rising Great Plains fire campaign: citizenry response to woody plant encroachment. Frontiers in Ecology and the Environment 11:e64-e71. DOI: 10.1890/130015
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Twidwell, Dirac, Samuel D. Fuhlendorf, Charles A. Taylor, Jr. & William E. Rogers (2013) Refining thresholds in coupled fire-vegetation models to improve management of encroaching woody plants in grasslands. Journal of Applied Ecology 50:603-613. DOI:11/1365-2664.12063
• Type: Journal Articles Status: Awaiting Publication Year Published: 2014 Citation: Twidwell, Dirac, Carissa L. Wonkka, Charles A. Taylor, Jr., Chris B. Zou, Jeremiah J. Twidwell & William E. Rogers (2014) Drought-induced woody plant mortality in an encroached semiarid savanna depends on topoedaphic factors and land management. Applied Vegetation Science 17:42-52. DOI: 10.1111\avsc.12044
• Type: Journal Articles Status: Awaiting Publication Year Published: 2014 Citation: Twidwell, Dirac, Jennifer M. Meza, Charles J. Turney & William E. Rogers (2014) Does prescribed fire facilitate fire ant invasions in coastal prairies or aid management efforts by improving mound search efforts? Southeastern Naturalist. In press
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Dirac Twidwell, Samuel D. Fuhlendorf , Brady Allred & William E. Rogers. 2013. Moving toward a more dynamic platform for restoration and the need to consider extreme disturbance events. Abstracts, Society for Ecological Restoration International, 5th World Conference, Madison, WI.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: William E. Rogers, Dirac Twidwell , Carissa L. Wonkka , Urs P. Kreuter, Charles A. Taylor, Jr. 2013. Can novel combinations of prescribed extreme fire and herbicide be used to overcome resprouting woody plant resilience and restore degraded rangelands in the southern Great Plains? Abstracts, Ecological Society of America 98th Annual Meeting, Minneapolis, MN
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Carissa L. Wonkka, Dirac Twidwell, Charles A. Taylor Jr. Chris B. Zou, Jeremiah J. Twidwell & William E. Rogers. 2013. Patch-specific woody plant mortality following severe drought in a semi-arid Texas savanna. Abstracts, Ecological Society of America 98th Annual Meeting, Minneapolis, MN
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Carissa L. Wonkka, Dirac Twidwell, Charles A. Taylor Jr. Chris B. Zou, Jeremiah J. Twidwell & William E. Rogers. 2013. Topoedaphic factors and land management drive patchy drought-induced woody mortality in an encroached semiarid savanna: comparing the 1950s to the 2000s. Abstracts, 56th International Association of Vegetation Science, Tartu, Estonia.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Carissa L. Wonkka, William E. Rogers & Dirac Twidwell. 2013. An experimental assessment of different restoration practices in a brush encroached south Texas rangeland. Abstracts, Society of Range Management Annual Meeting, Oklahoma City, OK.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Michele D. Clark, William E. Rogers, Carissa L. Wonkka, Deseri Nally, Richard W. Teague, Urs P. Kreuter & James Muir. 2013. The interactive effects of prescribed fire and ungulate grazing on bankrupt bush (Seriphium plumosum) in a South African highveld grassland. Abstracts, Society of Range Management Annual Meeting, Oklahoma City, OK.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Ms. Gabriela Sosa, the student who is principally responsible for these studies, has now completed the third year of her doctoral program in the Rogers laboratory. She previously worked on many of the same projects for her Masters' Thesis from 2007-2009. At present, she is monitoring the existing and on-going studies developed for her doctoral dissertation research. All of these studies examine various aspects of fire effects on Opuntia cactus. Funding is no longer available for these projects and they are nearing completion. During summer 2012 Gabriela was selected as a Chief's Scholar to work in Washington D.C. as a Natural Resource Specialist in the US Forest Service. She was one out of 16 graduate students selected from across the United States to take part in this leadership development training program. As a result of the positive impression she made this past summer, Gabriela has been offered a full-time position with the United States Forest Service as an Ecologist in the Rangelands Management staff working in Washington DC after the successful completion of her dissertation. Dr. Dirac Twidwell, another doctoral student participating in this effort graduated in spring 2012 and is currently employed as a post-doctoral research associate in the Department of Natural Resource Ecology and Management at Oklahoma State University. He has been very producing publications from his dissertation research. Moreover, this project has allowed the graduate students involved to train and mentor Texas A&M undergraduates and high school students as they assist in conducting scientific research. The undergraduates and high school students have gained hands on field experiences and have increased their understanding of ecological studies within degraded ecosystems. These mentoring roles have allowed the graduate students to develop leadership skills as they complete their PhD research programs. Gabriela was selected by the Alfred P. Sloan Foundation in October 2012 to be a panelist at the annual institute meeting held in Tampa, Florida in order to share her educational journey and current doctoral research with Sloan Scholars and Sloan Directors and Mentors. She was also invited to present a seminar hosted by Research & Development at the US Forest Service headquarters in Washington D.C. on "Strategies for Restoring Degraded Rangelands: Addressing Cacti Encroachment" in August 2012. Dirac has given multiple presentations to various stakeholder groups. The future success of land management in Texas depends on collaboration and support from institutions of higher education in our region. In addition, we have given numerous presentations of our research at national and local professional meetings and are working on manuscripts and scientific publications related to these efforts that will be broadly disseminated to the international ecological community. PARTICIPANTS: Gabriela Sosa and Dirac Twidwell, current and former graduate students in the Department of Ecosystem Science and Management, respectively, who have contributed to various aspects of these efforts. Drs. Urs Kreuter and Charles A. Taylor, Jr., professors in the Department of Ecosystem Science and Management, and Dr. Terry Blankenship, Director of the Welder Wildlife Refuge, also contributed to various aspects of these efforts. Undergraduate and high school field assistants. TARGET AUDIENCES: Scientific community, rangeland managers and Texas landowners. PROJECT MODIFICATIONS: No significant modifications regarding existing studies have occurred during this reporting period.

Impacts
Experiment #1: The final census of cacti for this study was conducted in December 2012. Ms. Gabriela Sosa is currently analyzing the data and developing a chapter in her dissertation from these results. A peer-reviewed publication will ultimately result from this effort following the successful defense of her dissertation. Experiment #2: This study has been completed and we are finalizing the results for a manuscript that will be submitted to a scientific publication. Experiment #3: The rainfall exclusion treatments are currently still in place. The final rainfall addition treatments have been completed. The prescribed fires have been conducted and we will continue to monitor the plots for post-treatment responses through at-least May 2013. Ms. Gabriela Sosa will collect the final data for inclusion in her dissertation at this time, but the continuation or termination (and harvesting of aboveground plant tissue to assess plant productivity and recovery) of the study will not be definitively determined until necessary. The complementary nature of these two studies manipulating precipitation will allow us to better understand the ecological mechanisms contributing to Opuntia resilience and invasiveness, as well as, allow us to make management recommendations regarding the ecological and climatic conditions best suited for controlling prickly pear with fire. A peer-reviewed publication will ultimately result from this effort following the successful defense of her dissertation.

Publications

• Twidwell, Dirac, William E. Rogers, Elizabeth A. McMahon, Bryce R. Thomas, Urs P. Kreuter & Terry Blankenship. 2012. Prescribed extreme fire effects on richness and invasion in coastal prairie. Invasive Plant Science and Management 5:330-340.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Ms. Gabriela Sosa, the student who is principally responsible for these studies, has now completed the second year of her doctoral program in the Rogers laboratory. She previously worked on many of the same projects for her Masters' Thesis from 2007-2009. At present, she is monitoring the existing and on-going studies developed for her doctoral dissertation research. All of these studies examine various aspects of fire effects on Opuntia cactus. Funding to support Gabriela for three years has been obtained via a TAMU Diversity Fellowship. She also has some research funds from the Sloan Foundation and the Hispanic Leaders in Agriculture and the Environment (HLAE) program. Dirac Twidwell, another doctoral student participating in this effort, completed his dissertation defense in December 2011 and will graduate in Spring 2012. This project has allowed the graduate students involved to train and mentor Texas A&M undergraduates and high school students as they assist in conducting scientific research. The undergraduates and high school students have gained hands on field experiences and have increased their understanding of ecological studies within degraded ecosystems. These mentoring roles have allowed the graduate students to develop leadership skills as they complete their PhD research programs. Gabriela was selected to present the progress of this research project with TAMU System Regent and Chancellor during a special briefing organized in the College of Agriculture and Life Sciences in November 2011. The future success of land management in Texas depends on collaboration and support from institutions of higher education in our region. In addition, we have given numerous presentations of our research at national and local professional meetings and are working on manuscripts and scientific publications related to these efforts that will be broadly disseminated to the international ecological community, as well as, a variety of Texas land managers and stakeholders. PARTICIPANTS: Gabriela Sosa and Dirac Twidwell are the graduate students in the Department of Ecosystem Science and Management who have contributed to various aspects of these efforts. Drs. Urs Kreuter and Charles A. Taylor, Jr., professors in the Department of Ecosystem Science and Management also contributed to various aspects of these efforts. Undergraduate and high school field assistants. TARGET AUDIENCES: Scientific community, rangeland managers and Texas landowners. PROJECT MODIFICATIONS: No significant modifications regarding existing studies have occurred during this reporting period. PARTICIPANTS: Gabriela Sosa and Dirac Twidwell are the graduate students in the Department of Ecosystem Science and Management who have contributed to various aspects of these efforts. Drs. Urs Kreuter and Charles A. Taylor, Jr., professors in the Department of Ecosystem Science and Management also contributed to various aspects of these efforts. Undergraduate and high school field assistants. TARGET AUDIENCES: Scientific community, rangeland managers and Texas landowners. PROJECT MODIFICATIONS: No significant modifications regarding existing studies have occurred during this reporting period.

Impacts
Experiment #1 Current status - One third of these plots were scheduled to receive a second fire treatment in September 2009, but fine fuel conditions were inadequate to conduct fires of sufficient intensity. As a result, the prescribed burns in the repeatedly burned plots were conducted during October 2010. The cactus mottes in these plots were reassessed in December 2010 and a final time in December 2011. We will likely continue to monitor this experiment throughout the next year to provide a quantitative measure of the effectiveness and duration of our management efforts. Results from this study will be incorporated into Gabriela Sosa's doctoral dissertation and eventually published in the scientific literature. Experiment # 2 Current status - This experimental study constituted the primary component of Ms. Sosa's thesis. We collected the final survival, growth, and biomass data on these plants in March 2010. This provided us with two complete years of data from the time the initial fire treatments were administered. We are presently finalizing the statistical analysis of these results and are currently preparing a manuscript that will be submitted to a scientific research publication (e.g., Rangeland Ecology and Management, Restoration Ecology). Experiment #3 Current status - The precipitation addition treatments were re-administered in August 2011 and the water exclusion treatments are still active. The prescribed fires were conducted during the winter of 2011 and another set will be conducted in summer 2012. Follow-up measurements will be conducted regularly for an extended period of time. We will assess herbivory and fire damage on existing and new cladodes and continue monitoring environmental variables throughout the study period. Results from this study will be incorporated into Gabriela Sosa's doctoral dissertation.

Publications

• Dirac Twidwell, William E. Rogers & Charles A. Taylor, Jr. 2011. Published Abstract, Ecological Society of America 96th Annual Meeting, Austin, TX. Applying prescribed extreme fire within a resilience framework to help stakeholders adapt to changing rangeland environments. William E. Rogers, Dirac Twidwell, Elizabeth A. McMahon, Bryce R. Thomas, Urs P. Kreuter & Terry L. Blankenship. 2011. Published Abstract, Ecological Society of America 96th Annual Meeting, Austin, TX. Using prescribed extreme fire for coastal prairie restoration: effects on species richness and invasion.
• Dirac Twidwell & William E. Rogers. 2011. Welder Wildlife Student Symposium, Sinton, TX. Published Abstract, Prairie and savanna restoration with controlled wildfire.
• Gabriela Sosa, William E. Rogers & Charles A. Taylor, Jr. 2011. Grasslands in a Global Context: Konza Prairie Anniversary Symposium, Manhattan, KS. Published Abstract, Reducing prickly pear encroachment with prescribed fire.
• William E. Rogers, Dirac Twidwell & Terry L. Blankenship. 2011. West Gulf Coastal Plain and Big Thicket Science Conference, Nacogdoches, TX. Published Abstract, Restoring west Gulf coastal prairies using prescribed extreme fires.
• Dirac Twidwell, Jennifer M. Meza, C. Jack Turney & William E. Rogers. 2011. West Gulf Coastal Plain and Big Thicket Science Conference, Nacogdoches, TX. Published Abstract, Alien fire ant and native harvester ant responses to coastal prairie restoration with fire.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Ms. Gabriela Sosa, the student who is principally responsible for these studies, has now completed the first year of her doctoral program in the Rogers laboratory. She previously worked on many of the same projects for her Masters' Thesis from 2007-2009. At present, she is monitoring the existing and on-going studies, as well as developing new experiments, for her doctoral dissertation research. All of these studies examine various aspects of fire effects on Opuntia cactus. Funding to support Gabriela for three years has been obtained via a TAMU Diversity Fellowship. She also has some research funds from the Sloan Foundation and the Hispanic Leaders in Agriculture and the Environment (HLAE) program. She has submitted and EPA-STAR fellowship proposal and we are actively pursuing additional external funding opportunities to continue and expand these research efforts. We have given numerous presentations of our research and are working on manuscripts and scientific publications related to these efforts that will be broadly disseminated to the international ecological community, as well as, a variety of Texas land managers and stakeholders. PARTICIPANTS: Gabriela Sosa and Dirac Twidwell are graduate students in the Department of Ecosystem Science and Management who contributed to various aspects of these efforts. Dr. Charles A. Taylor, Jr., Professor in the Department of Ecosystem Science and Management and Texas AgriLife Research also contributed to various aspects of these efforts. TARGET AUDIENCES: Scientific community, rangeland managers and Texas landowners PROJECT MODIFICATIONS: New experimental efforts involving rainfall exclosure manipulations have been added to Experiment #3. We are in the preliminary phases of data collection for this effort. No other significant modifications regarding existing studies have occurred during this reporting period.

Impacts
Experiment #1: One third of these plots were scheduled to receive a second fire treatment in September 2009, but fine fuel conditions were inadequate to conduct fires of sufficient intensity. As a result, the prescribed burns in the repeatedly burned plots (1/3 of the total number of plots) were conducted during October 2010. The cactus mottes in these plots were reassessed in December 2010. We plan to continue monitoring this experiment throughout the next 2 years to provide a quantitative measure of the effectiveness and duration of our management efforts. Experiment #2: We collected the final survival, growth, and biomass data on these plants in March 2010. This provided us with two complete years of data from the time the initial fire treatments were administered. We are presently finalizing the results for a manuscript that will be submitted to a scientific publication. Experiment #3: Conditions have required us to continually postpone the prescribed fires for this study. Our plan is to re-administer the precipitation addition treatments in August 2011 and conduct the prescribed fires shortly thereafter. In August 2010, as a companion effort to this water addition study, we randomly selected 60 additional nearby cacti mottes, built and erected 30 rain-out shelters that were placed approximately 1m above randomly selected mottes. These rainfall manipulation treatments were factorially crossed with a randomly assigned prescribed burn treatment thereby providing 15 replicates of each of the following four experimental combinations: i) decreased rainfall with fire, ii) decreased rainfall without fire, iii) ambient rainfall with fire, and iv) ambient rainfall without fire. The rainfall exclusion will continue until August 2011 at which time we will attempt to conduct the prescribed fires for this study. The complementary nature of these two studies manipulating precipitation will allow us to better understand the ecological mechanisms contributing to Opuntia resilience and invasiveness, as well as, allow us to make management recommendations regarding the ecological and climatic conditions best suited for controlling prickly pear with fire. Follow-up measurements will be conducted regularly for an extended period of time.

Publications

• William E. Rogers (2010) USDA-AFRI Regional CAP Planning Grant Meeting, Arlington, TX, Using prescribed extreme fire to restore degraded rangelands in the Edwards Plateau region.
• Dirac Twidwell, William E. Rogers, Samuel D. Fuhlendorf, and Charles A. Taylor, Jr. (2010) Ecological Society of America 95th Annual Meeting, Pittsburgh, PA, Using prescribed extreme fire to collapse and restore ecological systems: the benefits of quantifying resilience.
• William E. Rogers, Dirac Twidwell, Gabriela Sosa, and Charles A. Taylor, Jr. (2010) Ecological Society of America 95th Annual Meeting, Pittsburgh, PA, Restoring shrub invaded rangelands with prescribed extreme fire.
• William E. Rogers, Dirac Twidwell, Gabriela Sosa, Charles A. Taylor, Jr. (2010) Society of Range Management-Weed Science Society of America Joint Meeting, Denver, CO, Prescribed extreme fire for restoring Texas rangelands degraded by persistent invasive plants.
• Gabriela Sosa, William E. Rogers, Dirac Twidwell, and Charles A. Taylor Jr. (2010) Student Research Week-Ecological Integration Symposium, College Station, TX. Poster: Restoring a Degraded Rangeland: Examining the effects of seasonality and herbivory on Opuntia Cacti Management.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Ms. Gabriela Sosa, the Masters-level graduate student taking the lead on many of these studies, successfully defended her Masters of Science thesis in the Department of Ecosystem Science and Management at Texas A&M University this past fall semester. We still intend to collect additional data on these studies and publish our results in a scientific journal later this year. Gabriela has also started her doctoral program in The Rogers Laboratory and she is continuing to monitor these studies, as well as develop new experiments, examining fire effects on Opuntia cactus for her PhD dissertation research. Funding to support Gabriela for three years has been obtained via a TAMU Diversity Fellowship. She also has some research funds from the Sloan Foundation and the Hispanic Leaders in Agriculture and the Environment (HLAE) program. We are actively pursuing additional external funding opportunities to continue and expand these research efforts. PARTICIPANTS: Gabriela Sosa and Dirac Twidwell are graduate students in the Department of Ecosystem Science and Management who contributed to various aspects of these efforts. Drs. Urs Kreuter and Charles A. Taylor, Jr., professors in the Department of Ecosystem Science and Management also contributed to various aspects of these efforts. TARGET AUDIENCES: Scientific community, rangeland managers and Texas landowners. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Experiment #1 - Impact of hot summer fire and fire frequency on Opuntia growth and survival. Current status - One third of these plots will receive a second fire treatment in early summer 2010. Follow-up measurements will be conducted on all plants in late 2010. Results from this study will be incorporated into Gabriela Sosa's doctoral dissertation and ultimately published in peer-reviewed journals. Experiment # 2 - Fire seasonality and wildlife herbivory effects on Opuntia cactus encroachment. Current status - This experimental study constituted the primary component of Ms. Sosa's thesis. We will continue collect a final survival and growth data inventory on these plants in early 2010 before finalizing the results for a manuscript that will be submitted to a scientific research. Experiment #3 - Effects of fire, precipitation and ungulate herbivory on Opuntia cactus. Current status - Our plan is to re-administer the precipitation treatments in August 2010 and then conduct prescribed fires during September 2010 during a time of water limitation. Follow-up measurements will be conducted regularly thereafter. We will assess herbivory and fire damage on existing and new cladodes and continue monitoring environmental variables throughout the study period. Results from this study will be incorporated into Gabriela Sosa's doctoral dissertation.

Publications

• William E Rogers, Dirac Twidwell, Gabriela Sosa, Charles A. Taylor, Jr(2010) Society of Range Management meeting, Denver, CO. Published Abstract, Prescribed extreme fire for restoring Texas rangelands degraded by persistent invasive plant.
• Gabriela Sosa(2009) Restoring a Degraded Rangeland: Using Fire and Herbivory to Control Opuntia Cacti Encroachment. Masters of Science Thesis from Texas A&M University, College Station, TX. Chair of Advisory Committee: Dr. William E Rogers.
• Urs P Kreuter, W Richard Teague, J Richard Conner, William E Rogers, Charles A Taylor, Jr.(2009) 19th Conference of the Society for Ecological Restoration International, Perth, Australia. Published Abstract, Using extreme fire to restore ecosystems in the southern plains: an ecological, economic and social evaluation.
• Gabriela Sosa, William E Rogers, Charles A Taylor, Jr., and Dirac Twidwell(2009)19th Conference of the Society for Ecological Restoration International, Perth, Australia. Published Abstract, Restoring a degraded rangeland: using fire and herbivory to control Opuntia cacti encroachment.
• Gabriela Sosa, William E Rogers, Dirac Twidwell and Charles A Taylor, Jr(2009) 12th Annual TAMU Student Research Week, College Station, TX. Published Abstract, Prescribed fire as a management tool to prevent Opuntia cacti encroachment.
• Urs Kreuter, W Richard Teague, William E Rogers, Charles A Taylor and D Lynn Drawe(2009) Society of Range Management meeting, Albuquerque, NM. Published Abstract, Ecological, economic, and social dimensions of using summer fire to restore ecosystems in the southern plains of the US.