Ecosystem recovery from a major hurricane: insights from high-frequency aquatic sensors

Hurricanes are a major disturbance in many tropical island ecosystems delivering pulses of sea salt, sediment and nutrients to freshwater ecosystems. The advent of high-frequency sensors now allows us to track the recovery of ecosystems from these major events in novel and unprecedented ways. Here we examine the effect of Hurricane Maria a category 5 storm that made a direct hit to the Luquillo Mountains, Puerto Rico, September 2017. We use data from two instrumented watersheds which vary in lithology to study and compare the response of specific conductance and turbidity from before, during and the following two years post hurricane. Specific conductance and turbidity showed a strong response during the hurricane with fundamentally altered concentration-discharge relationships indicating large amounts of entrained sea salt and potential landslides across these watersheds. Post-storm analyses indicate that the early stages of ecosystem recovery are initially associated with highly variable concentration-discharge (C-Q) relationships followed by a period of more homogenized C-Q patterns potentially due to forests existing in an early secondary successional stage where reservoirs of solutes and sediment have been depleted. These insights prove useful to understanding how watershed exports respond to and recover from disturbance.