Arbuscular mycorrhizal fungi (AMF) form symbioses with plant roots and aid in nutrient absorption. While the overall importance of AMF is well established, the effect of land use in The Cross Timbers Ecoregion (CTE) on AMF is not. CTE, also known as ecoregion 29, covers approximately 4.8 million ha from southeastern Kansas across Central Oklahoma to Central Texas. It is home to 200-to 400-year-old post oaks and rare pre-settlement vegetation, making it a living natural history museum. This ecoregion is most threatened by habitat destruction, overexploitation, fire suppression, habitat fragmentation, overgrazing, and urban development in Texas. In order to understand mycorrhizal fungi to conserve the CTE of Texas we decided to compare the difference in AMF levels in Remnant Plot (RP) versus Open Grassland Plot (OP) and Agriculture Plot (AP). We collected random soil samples from the wooded RP, OP formerly used as agriculture land but not plowed in 10 years, and AP used to grow winter wheat and hay at Weatherford College Carter Farm and compared the spore density and AMF colonization in the roots collected from samples.
Results/Conclusions
Our data comparing spore counts extracted from the RP, OP and AP shows significantly (p<0.0001) higher spore density at the AP (30.82±4.17 spores per gram dry soil) which is plowed every year to grow hay and winter wheat compared to RP (5.80±3.02 spores per gram dry soil) which is wooded and never plowed and OP (2.88±0.75 spores per gram dry soil) which has not been plowed in the last 10 years. Significantly higher spore density on the AP indicates that the plot has higher AMF production compared to the other two plots. It further indicates that the plants growing at the AP may be more highly dependent on the AMF. Lower spore density at the RP and OP might also be because of the fire suppression and other factors. Studies on the roots from these soil samples is currently still taking place, as we hypothesize that AMF colonization will be higher in the roots of the AP, as indicated by the spore density findings. Further study should focus on the application of controlled fire and grazing at the plots to mimic natural processes of maintaining the CTE. It is concluded from these results that frequent disturbances increase the spore density.