@article{dick_gardner_frene_heitman_sucre_leggett_2022, title={Forest floor manipulation effects on the relationship between aggregate stability and ectomycorrhizal fungi}, volume={505}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2021.119873}, abstractNote={Forest floor and mineral soil manipulations influence the soil biogeochemical properties important for loblolly pine (Pinus taeda L.) tree growth. The impacts of forest floor manipulations on soil aggregate stability and the presence of ectomycorrhizal fungi (EMF), was assessed to elucidate the relationship between EMF abundance and aggregate stability. The study site consists of a 14-year-old loblolly pine plantation managed by Weyerhaeuser Company in the Lower Coastal Plain, approximately 8 miles east of New Bern, North Carolina, USA. The soil samples were collected from the top 7.62 cm of each soil treatment which includes three levels of forest floor retention: removed, control, and doubled and two levels of forest floor mixing with the mineral soil: mixed and unmixed. Ectomycorrhizal fungi abundance was evaluated by ester-linked fatty acid methyl ester analysis and microbial community functionality was assessed by acid-phosphatase activity measurement. Aggregate stability was assessed using the aggregate mean weight diameter approach. Results indicate that the forest floor manipulations had no significant impact on aggregate stability and EMF abundance. However, a positive relationship between EMF abundance and aggregate stability was identified. Removing the forest floor resulted in a soil bulk density increase of 0.18 g cm−3 compared to doubling the forest floor. Our results demonstrate that some mineral soil properties recover relatively quickly from forest floor manipulations. The study informs forest managers interested in how soil responds to forest floor manipulation and the interaction between EMF and aggregate stability.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Dick, David L. and Gardner, Terrence G. and Frene, Juan P. and Heitman, Joshua L. and Sucre, Eric B. and Leggett, Zakiya H.}, year={2022}, month={Feb} }
 @article{frene_frazier_liu_clark_parker_gardner_2021, title={Early Effect of Pine Biochar on Peach-Tree Planting on Microbial Community Composition and Enzymatic Activity}, volume={11}, ISSN={["2076-3417"]}, url={https://doi.org/10.3390/app11041473}, DOI={10.3390/app11041473}, abstractNote={Biochar offers several benefits as a soil amendment, including increased soil fertility, carbon sequestration, and water-holding capacity in nutrient-poor soils. In this study, soil samples with and without biochar additives were collected for two consecutive years from an experimental field plot to examine its effect on the microbial community structure and functions in sandy soils under peach-trees (Prunus persica). The four treatments evaluated consisted of two different rates of biochar incorporated into the soil (5%, and 10%, v/v), one “dynamic” surface application of biochar, and a 0% biochar control. Fatty acid methyl ester (FAME) analysis was used to assess the microbial community structure, and enzyme activities involved in C, N, P, and S nutrient cycling were used as a means of assessing soil functionality. Total FAME and bacterial indicators increased by 18% and 12%, respectively, in the 10% incorporated and 5% surface applied treatments. Biochar applications increased β-glucosaminidase and arylsulfatase activities, 5–30% and 12–46%, respectively. β-glucosidase and acid phosphatase activities decreased by approximately 18–35% and 5–22% in the 0–15 cm soils. The overall results suggest that biochar’s addition to the sandy soils stimulated microbial activity, contributing to the increased mean weight diameter (MWD), C sequestration, and consequential soil health. The changes in microbial community structure and functions may be useful predictors of modifications in soil organic matter (SOM) dynamics due to the long-term application of pine biochar in these systems.}, number={4}, journal={APPLIED SCIENCES-BASEL}, author={Frene, Juan Pablo and Frazier, Mattie and Liu, Shuang and Clark, Bernadette and Parker, Michael and Gardner, Terrence}, year={2021}, month={Feb} }