** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** OUR LONG-TERM GOAL IS TO BETTER UNDERSTAND HOW ANTHROPOGENIC LEGACIES ARE SHAPING/ALTERING SOIL DEVELOPMENT, PROPERTIES, AND THEIR EVOLUTION. WE WILL INVESTIGATE THE PHYSICAL, CHEMICAL, AND MICROBIAL CHARACTERISTICS OF RIPARIAN SOILS UPSTREAM AND DOWNSTREAM OF EXISTING AND REMOVED DAMS IN THE CHIQUES CREEK WATERSHED IN PENNSYLVANIA. KEY QUESTIONS ARE: HOW HAVE MILLDAMS INFLUENCED THE PHYSICAL, CHEMICAL, AND MICROBIAL REGIME OF RIPARIAN SOILS UPSTREAM AND DOWNSTREAM OF THE DAMS? HOW DO THE SOIL CHARACTERISTICS CHANGE WITH TIME FOLLOWING DAM REMOVAL (SHORT AND LONG TERM TRENDS)? WE WILL INTENSIVELY MONITOR THE RIPARIAN SOIL PROPERTIES FOR A 2.4 M TALL MILLDAM THAT IS SLATED TO BE REMOVED IN SUMMER OF 2023. MONITORING WILL BE CONDUCTED BEFORE AND AFTER (FOR 3 YEARS) DAM REMOVAL AND WILL PROVIDE IMPORTANT NOVEL INSIGHTS INTO RAPID SOIL CHANGES FOLLOWING DAM REMOVAL. IN ADDITION, FIVE OTHER SITES IN THE CHIQUES CREEK WATERSHED, WHERE THE DAMS HAVE BEEN LONG REMOVED (5 TO 100 YEARS SINCE REMOVAL), WILL BE STUDIED TO INVESTIGATE THE LONG-TERM EVOLUTION OF SOIL PROPERTIES FOLLOWING DAM REMOVAL. SOIL PHYSICAL CHARACTERISTICS THAT WILL BE MEASURED INCLUDE: COLOR, BULK DENSITY, AGGREGATE STABILITY, AND TEXTURE. CHEMICAL CHARACTERIZATION WILL FOCUS ON SOIL NITROGEN AND ORGANIC CARBON CONCENTRATIONS AND FORMS, N PROCESS RATES, AND ASSOCIATED BIOAVAILABLE FE CONCENTRATIONS. MICROBIAL COMPOSITION WILL BE CHARACTERIZED USING HIGH THROUGHPUT SEQUENCING AND FUNCTIONAL GENES USING REAL-TIME QPCR. COMPARISONS OF THIS DATA WILL HELP US DEVELOP NEW PARADIGMS AND MODELS FOR ANTHROPOGENIC ALTERATION OF SOILS AND THEIR EVOLUTION.