AIMS_SE_Approach2_Weyerhaeuser_EEAS

This study was in the Weyerhaeuser watershed (outlet: 32.9841, -88.0133), located on private land in Greene County, AL, near Eutaw. It drains a non-perennial tributary to Shambley Creek and includes 0.70 km² of coniferous forest managed for silviculture within the East Gulf Coastal Plain. Elevation ranges from 63 to 94 m, and the watershed contributes to the Sipsey River (Mobile-Tombigbee basin). The area also has a humid subtropical climate, with mean January and July temperatures of 7.3°C and 27.4°C, and annual precipitation of 1,350 mm. This watershed was included in a seasonal sampling survey (AIMS Approach 2) conducted from March 2022 to January 2024 as part of the Aquatic Intermittency effects on Microbiomes in Streams (AIMS) Project. The field team collected data on hydrology, biogeochemistry, and microbial ecology at 7 sites within each watershed. Site selection balanced three priorities: (1) targeting locations with existing long-term monitoring infrastructure; (2) including sites near springs and tributary confluences; and (3) capturing variability in drainage area and topographic wetness index (TWI), which are linked to flow permanence. At each site, samples of water (when present), biofilm, leaf litter, and sediment were collected. Microbial enzyme activities were measured to assess organic matter decomposition (β-glucosidase, phenol oxidase, peroxidase) and nutrient mineralization (N-acetylglucosaminidase for nitrogen, phosphatase for phosphorus). Enzyme activities were quantified using fluorometric methods with 4-methylumbelliferyl (MUB) substrates or colorimetric methods using 4-nitrophenyl (pNP) and L-DOPA substrates.