Arbuscular mycorrhizal fungi (AMF) forms a mutually symbiotic relationship with plant roots and aids in the absorption of nutrient and water, in return plant provides organic carbon to the fungi. The overall importance of AMF is well established; however, the effect of land use in Cross Timber Ecoregion (CTE) on AMF has not been explored well. The Cross Timber Ecoregion covers approximately 4.8 million hectors from southeastern Kansas across Central Oklahoma to Central Texas. 200-to 400-year-old post oaks and rare pre-settlement vegetation reside in the CTE region, making it a living national treasure. Habitat destruction and fragmentation, overexploitation, fire suppression, overgrazing, and urban development are all major threats to this natural history museum in Texas. In order to understand mycorrhizal fungi for the conservation of the CTE of Texas, we decided to compare differences in AMF levels in Remnant Cross Timber Plots (RP) versus Open Grassland Plots (OP) (formerly used as agriculture land but not plowed in 10 years) and Agriculture Plots (AP) (used to grow winter wheat and hay) at Weatherford College Carter Farm. Random soil samples were collected from these plots and compared for spore density and analysis of AMF colonization in the roots.
Results/Conclusions
The spore density in the soil represents the abundance of mycorrhizal fungi in the plant community. It was calculated from mycorrhizal slides created using the roots extracted from the soil sample. The highest spore density is found to be at the OP which has not been plowed in the last 10 years (24.82±4.17 spores per gram dry soil). AP which is plowed annually for the cultivation of hay and winter wheat shows 2.88±0.75 spores per gram dry soil. In comparison, RP which is wooded and never plowed has 5.80±3.02 spores per gram dry soil. Significantly higher spore density on the OP indicates that the plot has higher AMF production compared to the other two plots. It indicates that the plants growing at the OP may be dependent on the AMF for nutrients. Lower spore density at the RP may also be the result of fire suppression and other factors. And the spore density at the AP may have occurred because of plowing and use of fertilizers and herbicides. It can be concluded from these results that frequent disturbances decrease the spore density. This study should help ecological restoration managers to consider mycorrhizal fungi as a component of their restoration tool.