Climate change decreases the cooling effect from post‐fire albedo in boreal North America

Fires included in our analysis, which ranged between 1930 and 2013, aggregated to 100 km grid cells (a), and mean blue sky albedo composite for the month of April during 2000-2013 (b).

Climate change will lead to decreases in mean annual post‐fire albedo and a decreasing strength of the negative radiative forcing, according to research published recently in Global Change Biology.

This suggests climate change will decrease the strength of the cooling effect typically observed in post-fire landscapes.

GEODE lab lead Scott Goetz, post-doctoral scholar Richard Massey, along with NAU colleague Michelle Mack, collaborated with a team of researchers from Woods Hole Research Center (WHRC) to predict fire-driven changes in albedo under historical and future climate scenarios across boreal North America using WHRC’s MODIS-derived “blue sky” albedo product.

They estimate that, under historical climate conditions (1971-2000), fire induced changes in albedo generate an annual mean cooling of -1.77 ± 1.35 W m-2.

This is changing for fires burning in the modern era.

For fires that burned in the year 2016, models predict the cooling effect from long‐term post‐fire albedo will be reduced by 15%–28% due to climate change.

Read the full paper here.

Warmer, drier climate could transform Alaskan forests, according to fine-scale forest models

In a future with higher temperatures and other climate changes, Alaska’s boreal forests could look significantly different than they do now. According to a new study that is part of NASA’s Arctic Boreal Vulnerability Experiment (ABoVE), the warmer, drier conditions of the future could lead to a net loss of plant life in some regions of Alaska, while also changing the ratio of species that grow in them. These vegetation changes caused by global climate change could, in turn, affect Arctic climate in complex ways …

GEODE lab postdoctoral scholar Adrianna Foster has updated an individual-tree based forest model—the University of Virginia Forest Model Enhanced (UVAFME)— to improve simulation of forest dynamics and biotic-abiotic interactions in the boreal region.

Read more Adrianna’s modeling approach here

…and more about what the models are showing here.

To read the full paper, published in Ecological Modeling, see here.

Chasing caribou across a changing Arctic

I spent my summer searching for arctic spirits: barren-ground caribou who are, somehow, both omnipresent and elusive.

My journey, it turns out, would trace the migration route of the Porcupine caribou herd, linking boreal forest and arctic tundra ecosystems unlike any other northern mammal. The wild landscape I traveled forms the northern extent of the North American Cordillera, one of the last intact mountain ecosystems on Earth.

As I prepared, gathering groceries and loading the truck with scientific equipment and camping supplies, I heard whispers of the entire Porcupine herd moving southeast through the Richardson Mountains. Our small research team drove hurriedly north – hoping for a (figurative) collision course with hundreds of thousands of caribou at the Yukon/Northwest Territories border . . .

Katie Orndahl (left) and Rachel Pernick (right) scaling rocky slopes in search of caribou near the Yukon/Northwest Territory border

Visit the NASA Earth Expeditions blog to continue reading about GEODE lab PhD student Katie Orndahl’s adventures conducting field work this summer in the Canadian Arctic!

 

Larger, more frequent fires in boreal forest threaten previously protected carbon stores, NAU-led research team reports in Nature

Warmer, drier conditions and more frequent fires are contributing to the combustion of “legacy carbon” in the Northwest Territories, Canada, according to NAU ECOSS postdoctoral researcher Xanthe Walker, along with NAU senior authors Michelle Mack (ECOSS), Ted Schurr (ECOSS) and GEODE lead Scott Goetz.  These pools of carbon have historically been protected by thick organic soils, but shorter fire return intervals are making this carbon newly vulnerable.  As legacy carbon continues to burn, concerns mount that boreal forests could shift from a carbon sink to a carbon source and thus contribute to the acceleration of climate warming.

Read more about this work in NAU News.

Lead author Xanthe Walker was also featured in an NPR News Now episode.  Listen to Xanthe talk about this work here at around the 2 minute mark, or visit the NPR News Now website and navigate to the episode from August, 21, 2 PM ET, minute 2.

Above graphic by Victor O. LeshykEcoss

Animals and the zoogeochemistry of the carbon cycle

Chris Doughty (left) and Scott Goetz (right) discuss their research on the zoogeochemistry of the carbon cycle (photo credit: Shannon Swain)

From caribou in the arctic tundra, to monkeys in the tropical rainforest, animals play a large and often unrecognized role in the carbon cycle.  In a recent paper, GEODE lead Scott Goetz and NAU colleague Chris Doughty review existing research on these “zoogeochemical” effects and how they impact landscapes.  Recent advancements in spatial ecosystem ecology, remote sensing and geospatial statistical are providing the tools needed to finally understand animal impacts at a regional scale, and include these impacts in models of carbon cycling and climate change.  Some of this work is underway right now in the GEODE and Doughty Labs.

Read more about this research in the Arizona Daily Sun and NAU’s The LumberJack.

Remote sensing reveals impact of logging road expansion in Congo Basin

Photo credit: Nadine Laporte

Nadine Laporte, research professor in the School of Forestry, and Scott Goetz, professor in the School of Informatics, Computing, and Cyber Systems, are co-authors of a paper published in Nature Sustainability. “Road expansion and persistence in forests of the Congo Basin” studies the progressive expansion of logging roads across the Congo Basin. By comparing older and newer roads of different types, whether primary, secondary or logging roads derived from Landsat image time series data, the scientists show why the dramatic expansion is causing broad concern for forest ecosystems, carbon storage and wildlife vulnerable to subsistence hunting—and how decommissioning roads after logging could play a crucial role in reducing the negative impacts of timber extraction on tropical forest ecosystems.

Read more in NAU News.

Research identifies restoration hotspots in tropical rainforests

Photo credit: Nadine Laporte

School of Informatics, Computing, and Cyber Systems professor Scott Goetz is co-author of a study published July 3 in Science Advances. “Global restoration opportunities in tropical rainforest landscapes” identifies “restoration hotspots”—100 million hectares of lost lowland tropical rainforests in 15 countries across four continents—that could be restored now to boost the environment, biodiversity and climate change mitigation. “Tropical forest restoration and conservation go hand in hand,” Goetz said, “and there is much international political motivation to restore and conserve forests, so we need to collectively take advantage of this opportunity as soon as possible.”

Read more in NAU News.