Oaks may replace pines in severely burned ‘lost pines’ region without human intervention – agrilife todayagrilife today
“Our concern was that resprouting oaks may alter resources and make conditions unfavorable for pine reestablishment,” she said. Data recovery iphone 6 “We designed an experiment to test the effects of fire severity and soil type on the growth and leaf-level functions of resprouting post oaks, blackjack oaks and loblolly pines, hoping to better understand the physiology of the three species and how their long-term recovery may be affected.”
In July 2015 and 2016, Cooper and two other students measured resprout heights and diameters and collected leaf samples for nitrogen, carbon and phenolic compounds that would provide an indication of plant stress response.
“We took measurements in three soil types ranging from deep sands to shallower rocky soils and replicated those measurements in each soil type and burn severity combination three times for a total of 18 plots,” she said.
In 2016, the project expanded to include additional measurements to analyze foliar photosynthesis, water potential and hydraulic characteristics, which would increase understanding about water access and use by the three species, Cooper said.
Marco Minor and Ashley Cross, Texas A&M University students who help with the project, set up a plot in a severely burned patch to measure loblolly pine seedling and oak resprout heights and diameters. Database building (Texas A&M AgriLife photo by Caitlyn Cooper)
“We found that the degree of burn severity had more of an effect on growth than soil type,” she said. Data recovery top 10 “Pine seedling densities were much lower in severely burned areas than those that had experienced light burns. Database hosting Oak resprout densities were similar across burn severity, but the trees were smaller in the moderately burned plots than those that were severely burned.
“Reduced resprout growth in moderately burned plots may be due to increased competition with loblolly pine since we encountered a greater number of pine individuals in moderately burned areas than those that were severely burned.”
“Our leaf-level measurements suggested that the oak resprouts were better able to tolerate drought stress, while the pine seedlings were more conservative with water use and exhibited drought-avoidance characteristics,” Cooper said. Data recovery best “Post oak was more tolerant of drought stress than blackjack oak.”
In addition to the plots for evaluating oak resprout and pine seedling competition, Cooper established three sites to compare sap flow, a way to measure water use. Data recovery program Two of these sites were established in Bastrop State Park in moderately and severely burned regions, and the third was established at an unburned site at the Griffith League Ranch north of Bastrop.
“After the fire, we wanted to see if there was a difference in tree stand water use,” Moore said. 7 data recovery 94fbr “Plant density affects competition, and that affects how much water is available to individual trees.”
Caitlyn Cooper, an agronomy doctoral student at Texas A&M University, installs sap flow sensors in a loblolly pine at the moderately burned sap flow site. Database languages (Texas A&M AgriLife photo)
Cooper said they found a few of the overstory oaks and pines were killed, but the majority lived at the moderately burned site. Database ranking The entire overstory had been destroyed at the severely burned site. Data recovery youtube This site used much less water than the unburned and moderately burned sites due to the large reduction in tree density and size.
“We also found that mature pine trees use more water than mature oaks,” Cooper said. 911 database “So if the severely burned area returns with more oaks than pine in the future, it will likely continue to use less water than pine-dominated stands in other parts of the park. Data recovery download That, in turn, could mean more runoff.”
Initially, she said, that runoff is not a good thing because of the erosion it might cause, but as the land heals, it will leave more water for other plants.
To determine individual tree water use and then scale to the stand level, Cooper used sap-flow sensors on the stems of the trees. Data recovery after factory reset These sensors continuously record data to provide daily water use measurements. Database schema design These logs were kept for about six months.
“At the end of our study, we have determined that some of the severely burned areas will likely become oak-dominated if pines are not reintroduced by planting and resprouts are not managed,” she said. Database uml “And the move oak dominance could alter the water availability and runoff within those severely burned areas into the future.”