As Arctic soils warm, thawed permafrost releases nitrogen (N) that could stimulate plant productivity and thus offset soil carbon losses from tundra ecosystems. Although mycorrhizal fungi could facilitate plant access to permafrost-derived N, their exploration capacity beyond host plant root systems into deep, cold active layer soils adjacent to the […]
The world’s oceans are getting hotter and acidifying under climate change at unprecedented rates, threatening coastal and high-mountain communities, marine ecosystems, and global fishing stocks, according to a new Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) released this week by the United Nations Intergovernmental Panel […]
The Tundra Trait Team (TTT) database includes field-based measurements of key traits related to plant form and function at multiple sites across the tundra biome. This dataset can be used to address theoretical questions about plant strategy and trade-offs, trait?environment relationships and environmental filtering, and trait variation across spatial scales, […]
The release of permafrost-derived nitrogen (N) has the potential to fertilize tundra vegetation, which in turn may stimulate productivity and thus offset carbon (C) losses from thawing permafrost. Below-ground plant traits may mediate ecosystem response to permafrost thaw and associated feedbacks to the atmosphere by differentially conferring access to deep, […]
Water use efficiency (WUE), defined as the ratio of gross primary productivity and evapotranspiration at the ecosystem scale, is a critical variable linking the carbon and water cycles. Incorporating a dependency on vapor pressure deficit, apparent underlying WUE (uWUE) provides a better indicator of how terrestrial ecosystems respond to environmental […]
During the 2016-2017 academic year, Ecoss teamed up with STEM City to serve as a Flagstaff community STEM partner in the Scientists in the Classroom Program (http://www.flagstaffstemcity.com/scientists-in-the-classroom.html). Each month, Ecoss students, postdocs, faculty, and staff members visited Ms. Kathryn Wertz’s 6th grade science class at Sinagua Middle School to share […]
Climate change in high latitudes can lead to permafrost thaw, which in ice-rich soils can result in ground subsidence, or thermokarst. In interior Alaska, we examined seasonal and annual ecosystem CO2 exchange using static and automatic chamber measurements in three areas of a moist acidic tundra ecosystem undergoing varying degrees […]
Arctic tundra soils store large amounts of carbon (C) in organic soil layers hundreds to thousands of years old that insulate, and in some cases maintain, permafrost soilsl,2. Fire has been largely absent from most of this biome since the early Holocene epoch3, but its frequency and extent are increasing, […]
Microbial decomposition of soil carbon in high-latitude tundra underlain with permafrost is one of the most important, but poorly understood, potential positive feedbacks of greenhouse gas emissions from terrestrial ecosystems into the atmosphere in a warmer world1, 2, 3, 4. Using integrated metagenomic technologies, we showed that the microbial functional […]
Overview Fire, a natural ecological disturbance, has been suppressed in U.S. forests for much of the past century. This has prevented damage to property and protected timber resources, but has caused many forests to develop in an unnatural manner, resulting in dense stands of small trees that are now poised […]