Research

 

Ecohydrological and Ecogeomorphic Disturbances

I am  proud dad of three kids, passionate climber, physical geographer and Junior Scientist. I study if, when, and how forests respond to landscape disturbances. Disturbances may trigger important processes in forests, that may otherwise remain unobserved, thus, provoking biased and/or premature conclusions if ignored. Many of such processes occur in the 'critical zone'. The ’critical zone’ is the thin layer between the unweathered rock and the top of the forest canopy, thus including soils, water, biomass, and the atmosphere. In short: The ’critical zone’ is where rock meets life. Disturbances, often associated with Natural Hazards and thus also impacting societies, are ’an abrupt event that changes the previously understood [...] function of a system (Mirus et al., 2017). Landscape disturbances may trigger surficial processes which in turn affect biogeochemical cycling, particularly carbon cycling. In my research, I typically combine fieldwork, laboratory analysis, UAV aerial surveys, and computer models. My favorite tools are Physics-based models, such as developed from the scratch or Landlab,  which allows to directly explore causes and effects.

> Disturbance Hydrology

Blanco River affected by the Chaitén eruption (2008), Patagonia, Chile.

Drone-footage of Patagonian Rainforest in different degrees of disturbance.

Natural Landscape Disturbances in Patagonian Rainforests

Coastal Rainforests have been a source of inspiration not only for scientists, but also for artists including Chile’s most important author Pablo Neruda, who concluded ‘[He] who does not know the Chilean forests, does not know the planet’. Intact forests are essential to Earth’s habitats because forests accumulate carbon from the atmosphere in exchange for oxygen, regulate global climate patterns, and protect soil cover from erosion. Forest disturbances may lead to massive, pulsed releases of carbon into the atmosphere. Yet sometimes disturbances can drive atmospheric carbon drawdown. For example, landslides may transfer organic carbon stocks contained in soils and woody material into storage via rapid burial under debris, while subsequent forest regrowth acquires atmospheric carbon. It remains unclear if the net result of such dynamics lies in absorbing or releasing atmospheric CO2. Understanding the role of disturbances for the overall organic carbon storage efficiency, and, thus, the carbon cycling in forest ecosystems is still in its infancy. In my research, I explore such feedbacks and the underlying processes in  Patagonian rainforests, one of the global biodiversity hotspots and, as part of the temperate rainforests, member of the carbon store house #1  (also see RETROGRESS and Opportunities). To this end, I develop physical models and perform rigorous data science.

> Organic Carbon Budget of Volcanic Eruptions

> Post-Eruptive Landsliding

> Wind-Triggered Landsliding

> Post-Eruptive Fluvial Geometry

Forest plantations in the vicinity of Nacimiento township, Chile (2012).

Hydrological and Erosion Responses to Forest Management

Fast-growing exotic forest plantations require huge quantities of freshwater, while accelerating rates of rotational cycles push pressure on the slowly forming soil resources. How do the managed landscapes respond to ongoing climate change and/or intensifying forest management practices? How can we develop more sustainable forest management practices? Answering this question and making quantitative predictions builds the core of my research agenda on this topic. To this end, I develop models and field tools.

> Runoff Generation and Soil Erosion on Harvest Areas

> Geomorphic Work, Process Response, and Seasonal Logging

> Water Balances of Forest Plantations and Native Forests

> Einfluss unterschiedlicher forstwirtschaftlicher Praktiken auf die Abflussbildung und die Bodenerosion in experimentellen Einzugsgebieten in Südchile

> Rainfall Simulator 

Time-lapse movie of a stream in Napa Valley responding to the 2014-Napa earthquake (from video recorded by Mike Henry).

Earthquake Hydrology

Going back to reports by Pliny, The Elder or Emmanuel Kant, earthquakes have been described to trigger hydrological anomalies. Such anomalies go far beyond being mere curiosities, since earthquakes can provide us with intimate insights into water-tectonic coupling. In recent years, a lot of progress has been achieved to explain seismo-hydrological processes causing streamflows to increase or decrease following earthquakes. Yet, there is no general agreement and existing models hold true for single observations, but conflict when put together into a general process understanding. Why and how do streamflow, groundwater flow and soil water respond to earthquakes? How important are such high-magnitude but low-frequency disturbances for regional water balances. How do trees respond to changes in the shallow subsurface hydrology? Answering such question requires models and observations to test them. To this end, I develop groundwater flow models from the scratch to simulate earthquakes in groundwater flows.

> Streamflow responses in Headwater Catchments

> Shaking Water out of Soils

> Regional Changes in Streamflow after an Earthquake

> Ground Motion Thresholds

> Post-seismic Sediment Fluxes

> Bayesian Change Point Detection for Streamflow Responses to Earthquakes

> The Dendroecology of Earthquakes