Spring coherence in dissolved organic carbon export dominates total coherence in Boreal Shield forested catchments

Abstract

The wide range of forested landscapes in boreal environments store and cycle substantial amounts of carbon, although the capacity of these systems to act as either a carbon sink or source is uncertain under a changing climate. While there are clear reports of regional-scale increases in dissolved organic carbon (DOC) concentrations in streams and lakes, there remains substantial watershed-scale variability in these patterns. Coherence is a framework for examining if variables of interest within adjacent spatial units change synchronously or asynchronously through time and has been widely applied in the context of lentic hydrochemistry, and which can shed light on the relative importance of regional-vs. local-scale controls. The objective of this research was to quantify coherence in discharge, DOC concentrations, and DOC loads in forested boreal watersheds, and to what extent coherence varied by season …