{"id":76835,"date":"2026-01-21T13:45:40","date_gmt":"2026-01-21T20:45:40","guid":{"rendered":"https:\/\/in.nau.edu\/news\/?p=76835"},"modified":"2026-01-21T13:45:40","modified_gmt":"2026-01-21T20:45:40","slug":"boreal-forest-carbon","status":"publish","type":"post","link":"https:\/\/in.nau.edu\/news\/boreal-forest-carbon\/","title":{"rendered":"When deciduous forests burn, they release less carbon than coniferous forests"},"content":{"rendered":"

As climate change drives more frequent and severe wildfires across\u00a0forests\u00a0in Alaska and northwestern Canada,\u00a0scientists are asking a critical question:\u00a0Will these ecosystems continue to store carbon,\u00a0or\u00a0will they\u00a0become a growing source of\u00a0carbon\u00a0emissions?\u00a0New research published this week shows that\u00a0when these northern forests shift from coniferous\u00a0spruce\u00a0forests\u00a0to deciduous\u00a0aspen and birch forests,\u00a0they could release\u00a0substantially\u00a0less\u00a0carbon when they burn.<\/span>\u00a0<\/span><\/p>\n

The\u00a0National Science Foundation-funded\u00a0study, led by\u00a0researchers\u00a0from\u00a0the\u00a0<\/span>Center for Ecosystem Science and Society<\/span><\/a> (Ecoss) at NAU, found that boreal forests dominated by deciduous species lose <\/span>less than half as much carbon per unit area burned\u202fcompared to boreal forests dominated by black spruce trees, historically the most common species found in these cold, snowy locations. The researchers found that even under severe fire weather conditions, carbon losses in deciduous forest stands were consistently lower than those in conifer forests.<\/span>\u00a0<\/span><\/p>\n

The study\u00a0<\/span>was published<\/span><\/a>\u00a0<\/span>Jan.\u00a015\u00a0<\/span>in Nature Climate Change.\u00a0<\/span>\u00a0<\/span><\/p>\n

\u201cThis work shows that not all boreal forests burn the same way,\u201d said\u00a0<\/span>Betsy Black<\/span><\/b>, who led the study as part of her\u00a0master\u2019s\u00a0thesis research at\u00a0NAU. \u201cAs deciduous trees become more common after fire, they can fundamentally change how much carbon is lost to the atmosphere during future wildfires.\u201d\u00a0<\/span>\u00a0<\/span><\/p>\n

Boreal forests store a large fraction of the world\u2019s\u00a0land-based\u00a0carbon,\u00a0much of it locked away in thick organic soils that have accumulated over centuries. Historically, these forests have acted as\u00a0a carbon sink,\u00a0absorbing much more carbon dioxide than they release. But warming temperatures have increased fire size,\u00a0severity\u00a0and frequency,\u00a0raising concerns that boreal ecosystems could shift toward\u00a0releasing more carbon than they store,\u00a0accelerating\u00a0climate change.\u00a0<\/span>\u00a0<\/span><\/p>\n

\u201cOur previous research shows that deciduous forests can accumulate much more carbon after fire than spruce forests,\u201d said\u00a0<\/span>Michelle Mack<\/span><\/b>,\u00a0Regents\u2019 professor in the Department of Biological Sciences and\u00a0Ecoss\u00a0and\u00a0senior author\u00a0on\u00a0the study. \u201cBut we were curious about what happens to that carbon when these forests burn.\u00a0No one had measured that before.\u201d<\/span>\u00a0<\/span><\/p>\n

To answer that question, the team analyzed carbon pools and combustion losses in plots\u00a0in\u00a0nearly a\u00a0dozen large fire scars across Alaska and Yukon. They found that deciduous forests store\u00a0more carbon aboveground in combustion-resistant tree stems and less in deep organic soils that readily burn, resulting in lower overall carbon emissions during fires.<\/span>\u00a0<\/span><\/p>\n

The study also\u00a0revealed stark differences in what controls carbon loss\u00a0between\u00a0forest types. In conifer forests,\u00a0emissions\u00a0were driven primarily by bottom-up factors,\u00a0such as fuel availability and soil moisture. In contrast, carbon losses in\u00a0deciduous and mixed forests\u00a0were more sensitive to fire weather conditions.\u00a0<\/span>\u00a0<\/span><\/p>\n

\u201cSeeing weather play such a strong role in deciduous forests was surprising,\u00a0and it suggests that as climate change drives more extreme fire weather, these forests could become more vulnerable in the future,\u201d\u00a0said\u00a0<\/span>Xanthe Walker<\/span><\/b>,\u00a0Ecoss\u00a0professor and corresponding author.<\/span>\u00a0<\/span><\/p>\n

Together, the findings suggest that increasing deciduous dominance, which is\u00a0already widely\u00a0observed\u00a0following severe fires in northwestern North America,\u00a0could help slow the positive feedback between wildfire and climate warming by reducing carbon emissions per unit area burned.\u00a0By quantifying how much carbon is lost when deciduous forests burn\u00a0and\u00a0identifying\u00a0the conditions that control those losses, the study provides critical data for improving wildfire and carbon cycle models\u00a0and forecasting future global carbon dynamics.\u00a0<\/span>\u00a0<\/span><\/p>\n

Co-authors on the study include\u00a0<\/span>Scott Goetz<\/span><\/b>\u00a0and\u00a0<\/span>Logan Berner<\/span><\/b>\u00a0of\u00a0the School of Informatics,\u00a0Computing, and Cyber Systems\u00a0at\u00a0Northern Arizona University, along with\u00a0Brendan Rogers, Winslow Hansen, Anna Talucci, Stefano Potter and Jacqueline Dean from the Woodwell Climate Research Center and the Cary Institute of Ecosystem Studies.\u00a0This research was supported by the\u00a0National Science Foundation,\u00a0NASA\u00a0and\u00a0the Bonanza Creek Long-term Ecological Research Program.<\/span><\/p>\n

\"Northern<\/span><\/p>\n


\nJill Kimball | NAU Communications
\n(928) 523-2282 | jill.kimball@nau.edu<\/a><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

As climate change drives more frequent and severe wildfires across\u00a0forests\u00a0in Alaska and northwestern Canada,\u00a0scientists are asking a critical question:\u00a0Will these ecosystems continue to store carbon,\u00a0or\u00a0will they\u00a0become a growing source of\u00a0carbon\u00a0emissions?\u00a0New research published this week shows that\u00a0when these northern forests shift from coniferous\u00a0spruce\u00a0forests\u00a0to deciduous\u00a0aspen and birch forests,\u00a0they could release\u00a0substantially\u00a0less\u00a0carbon when they burn.\u00a0 The\u00a0National Science Foundation-funded\u00a0study, led…<\/a><\/p>\n","protected":false},"author":95,"featured_media":76836,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[11],"tags":[],"class_list":["post-76835","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research-academics"],"acf":[],"_links":{"self":[{"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/posts\/76835","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/users\/95"}],"replies":[{"embeddable":true,"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/comments?post=76835"}],"version-history":[{"count":0,"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/posts\/76835\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/media\/76836"}],"wp:attachment":[{"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/media?parent=76835"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/categories?post=76835"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/in.nau.edu\/news\/wp-json\/wp\/v2\/tags?post=76835"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}