The UMBS AmeriFlux tower looms above the canopy.

Above the canopy of mid-aged northern hardwoods, aspen, and old growth hemlock west of camp, a sentinel keeps watch over University of Michigan Biological Station’s (UMBS) 11,000 acres. The “AmeriFlux tower” is one of the most iconic pieces of research infrastructure in the station’s catalog  – and not just because of its impressive 150 foot stature.

The metal tower is equipped with an array of sophisticated tools that measure ecosystem CO2, water, and energy fluxes – the rate of flow of gases and other properties. It is one among a network of PI-managed sites in North, Central, and South America established to collaborate and compare data across major climate and ecological biomes.

But despite belonging to a vast network, the UMBS AmeriFlux tower distinguishes itself impressively. According to Co-PI Dr. Gil Bohrer, Professor of Civil Environmental and Geodetic Engineering at The Ohio State University, the UMBS tower boasts the highest quality long term data on forest carbon dynamics in the world. But what makes the data so rich? 

For one, longevity.

“We belong to a select club of ‘Core Sites’,” says Bohrer. “Very few flux towers in the world have been running for 20 years straight, with so few gaps in data collection.”

In addition to continuity, core sites are chosen based on ecosystem representation, length of prior data record, quality of existing data, and established ability of site PIs – including Bohrer, UMBS Associate Research Scientist Dr. Luke Nave, and UMBS researcher Dr. Chris Gough –  to provide continuity in site management. Site PIs are quick to recognize the efforts of UMBS Research Scientist Dr. Chris Vogel, who maintains tower operations and continuous data collection on site.

Another reason the UMBS tower is special is the critical linkage between AmeriFlux datasets and other robust long term UMBS-based terrestrial and climate research – including Gough’s Forest Accelerated Succession Experiment (FASET) and Forest Resilience Threshold Experiment (FoRTE) on forest plant diversity, age, and disturbance. In conjunction with this supporting ecological context, AmeriFlux data help answer questions about carbon storage and exchanges of gases and energy in terrestrial systems, the influence of vegetation type, land use, and disturbance history, and the effect of seasonal and long term climate changes. Plus, the dataset is open source, which means scientists from all over the world can use it to better understand complex environmental processes. 

“The wealth of ecological data together with the meteorological and flux data make for a powerful combination,” says Bohrer. “We have UV index, soil moisture, and leaf index data, both weekly and seasonally. This ecological data provides context and helps make sense of the flux.” 

He elaborates. “Our monitoring is dual. Our AmeriFlux tower exists in the middle of a large-scale forest disturbance experiment, so we’re collecting flux data that we can compare with data on forest age, diversity, and tree mortality. Manipulations like this usually happen in a small plot or greenhouse. Our situation is really unique.”

AmeriFlux monitoring aligns seamlessly with UMBS’s commitment to long term data collection – especially as it pertains to climate change. Investigating flux dynamics as a product of ecosystem context means better understanding how changes in forest structure affect outlook for carbon sequestration, greenhouse gases, and climate related changes that are only becoming increasingly urgent. 

The watch continues. 

For more on the UMBS AmeriFlux Core Site, visit our network page

A camera attached to the AmeriFlux tower provides real-time bird’s eye footage of the canopy below. Photo: Chris Gough