Environmental, biological, and leaf litter decomposition data in the Colorado River downstream of Glen Canyon Dam between 1998 and 2022

Yes, all data values are reasonable and within the valid range for measurement. The data release consists of 15 tabular data files (csv). These data were compiled to compare patterns and potential drivers of leaf litter decomposition in the Colorado River downstream of Glen Canyon Dam between 1998 and 2022. Objective(s) of our study were to compare the breakdown of cottonwood (Populus fremontii), willow (Salix exigua), and salt cedar (Tamarix chinensis) leaves to a previous decomposition experiment from 1998 (Pomeroy et al. 2000) that was conducted in the context of much cooler water temperatures, higher phosphorus concentrations, lower New Zealand mudsnail densities, and salt cedar litter that was unaffected by biocontrol beetles compared to 2022. These data represent air temperatures, river water temperatures, reservoir storage, water phosphorus concentrations, river discharge, leaf nutrient content, leaf masses throughout the decomposition experiment, and invertebrate abundances, biomass, and growth associated with leaf packs throughout the decomposition experiment in 1998 and 2022. These data were collected in the Colorado River downstream of Glen Canyon Dam in 2022. However, physicochemical variables were also compiled from various sources (i.e., Bureau of Reclamation Hydromet, U.S. Geological Survey gauge 09380000, National Oceanic and Atmosphere Administration). Estimates of leaf masses through time from 1998 were gathered from Pomeroy et al. (2000). These data were collected by the U.S. Geological Survey, researchers at Northern Arizona University, the Bureau of Reclamation, and National Oceanic and Atmosphere Administration. Field data, representing leaf masses and invertebrates, were collected in 2022 by the U.S. Geological Survey. Air temperatures from 1998 and 2022 were gathered from the National Oceanic and Atmosphere Administration, water temperatures and discharge from 1998 and 2022 were gathered from the U.S. Geological Survey gauge 09380000, Lake Powel Reservoir storage was collected from the Bureua of Reclamation, water nutrient data were collected by the U.S. Geological Survey (see Deemer et. al. 2023). These data can be used to estimate, visualize, and statistically compare leaf litter decay rates among leaf types and between 1998 and 2022, analyze and visualize patterns of reservoir storage, water temperatures, and discharge between 1998 and 2022, analyze and visualize patterns in leaf litter chemistry among different leaf types in 2022, analyze and visualize relationships between temperature increases and leaf litter mass lost between 1998 and 2022, analyze and visualize patterns of invertebrate assemblage abundance, biomass, and community composition among leaf types in 2022, and analyze and visualize patterns of New Zealand mudsnail size structure and growth rates in 2022.