The role of connectivity (or lack of it) on biogeochemical signal propagation

High-intensity rainfall events have become more frequent and occur erratically over the past decade. These intense storms can overwhelm agricultural soils and significantly modify the dynamics of drainage networks. Structural (legacy) connectivity, which self-organizes within the drainage system, interacts with functional (contemporary) connectivity—the various fluxes in and out of the system. Together, they affect the imprint of the landscape surficial mosaic and exert non-linear filters to key hydrogeomorphic and biochemical processes thereby impacting  transport and transformation of water and other constituent fluxes in and out of a watershed. 

In our study, we present a nested network of water–sediment–nutrient measurements strategically positioned within USDA-ARS LTAR (Long-Term Agricultural Research) drainage networks. This approach captures discrete snapshots of event hillslope evolution phases in space and with time to quantify the high spatial and temporal variability of property heterogeneity through the drainage network and the feebacks that heterogeneity modification has on fluxes in and out a hillslope. We propose a systems-based approach to identify key mechanisms and parameters driving system dynamics, aiming to develop monitoring schemes that account for both management practices and climate effects in agricultural watersheds. Researchers posit that both management practices and climate play a pivotal role in shaping the response of agricultural watersheds. Specifically, alterations in transport times and the fluxes of water, sediment, and nutrients are influenced by these factors. These findings contribute to a deeper understanding of landscape processes and serve as a foundation for developing improved management guidelines.