Exploring relationships between watershed properties and holocene loss-on-ignition records in high-elevation lakes, southern uinta mountains, Utah, USA

Sediment cores were retrieved from 12 lakes in the southern Uinta Mountains ranging in elevation from 2960 to 3475 m. Organic content was determined by loss-on-ignition (LOI) at 1-cm intervals (n = 2850), corresponding to 20 to similar to 100 yrs per sample. This data set was used to explore relationships between watershed variables and LOI records. Average LOI values are strongly correlated with lake elevation, elevation of the watershed, extent of late-lying snow and bare rock in the watershed, and the area of upstream lakes. Average LOI values are not significantly correlated with lake depth, or with lake or watershed area. The 12 LOI records can be visually divided into 3 groups with contrasting patterns: Steady, Trending, and Rising. Steady lakes have the lowest average LOI values, and are located in watersheds with the highest maximum elevations and the largest area of upstream lakes and late-lying snow. The most significant determinant on average LOI and LOI pattern is hydrologic through-flow as revealed by the configuration and number of inlets and outlets. The repetition of Steady, Trending, and Rising LOI patterns in different parts of the range, combined with contrasting LOI patterns in adjacent lakes, suggests that watershed characteristics strongly influence organic sedimentation.