From Icefield to Ocean: Explore the many ways that glaciers influence Alaska's coastal ecosystems
This 4-page publication describes glacier dynamics and ecology, the role that glaciers play in ocean processes, and the impacts of climate change on this dominant feature of Alaska's coastal ecosystems. This document is a product of the March 2013 Juneau Glacier Workshop (sponsored by the Alaska Climate Science Center), an interdisciplinary effort to establish a better understanding of the icefield to ocean system and identify key research and management questions to address in the future.
Ice2O: Assessing icefield-to-ocean change in the PCTR
ACRC and UAS are partnering with the USGS Alaska Science Center, the University of Alaska Fairbanks, the University of Washington, and Oregon State University on Ice2O, a new project supported by the Alaska Climate Science Center. Ice2O will integrate climate downscaling, snow accumulation, glacier mass balance and streamflow datasets, and then use the integrated database to assess glacier sensitivity to changes in climate forcing. We will perform the analysis at the basin scale, but integrate over the entire northern PCTR region. The sensitivity testing will be guided by colleagues in resource management and ecology in order to align our efforts with the “questions that matter”, that is those with large uncertainty and/or substantial management and economic impacts. By building on an observational foundation, and by incorporating external ecosystem expertise, we will enhance model accuracy and provide relevant, accurate information on glacier change in the PCTR to decision-makers. Our results will be presented in multiple formats to best facilitate engagement with both the science and management communities.
Stream discharge, snow-cover, soil drainage and yellow-cedar decline in the NPLCC region of southeast Alaska
In March 2015 a joint ACRC/PNW/BC Ministry of Forestry post-doctoral scholar will begin a two-year project modeling stream discharge, soil hydrology and snow accumulation across the NPCTR. We will use a novel model to create a regional snow-pack and unit-area discharge dataset. Snow-pack is critical to maintenance of regional streamflow and improved models will be used to predict when stream flow regime will change and where the most vulnerable watersheds exist. Identifying spatially explicit areas where snow-packs have and will decline is critical for prediction of current and future precipitation-dependent resources. We will focus specifically on historical and future projections of snow-pack and discharge in the PCTR. This will build upon a dataset currently being developed that examines snow-packs and discharge based on climate normals (1961-90; 1971-2000; 1981-2010). Model outputs will be validated using USGS and Water Survey of Canada hydrometric data, remote sensing products for snow-cover (eg. MODIS) and long-term climate station and snow course data across the region of interest. Ultimately, climate change projections that cover the widest range of scenarios will be used to create snow-cover and unit area discharge layers through to 2100 to identify areas of at-risk snow and significant change to hydrologic regimes. We are building off of and leveraging work originally funded by the BC Ministry of Forestry, using a unique blend of resources from PNW, ACRC, BC Ministry and the Hakai Institute.
Watersheds figure courtesy of Bill Floyd, BC Ministry of Forests, Lands, and Natural Resource Operations.
Acre for acre, streams of the coastal temperate rainforest along the Gulf of Alaska export 36 times as much dissolved organic carbon as the world average. Dissolved organic carbon derived from soils has a large biodegradable component, making it an important food source for freshwater and marine food webs. In the Tongass National Forest alone, there are 14,000 streams exporting these high-value nutrients to the estuaries that support Alaska’s $5 billion fishing industry.
Jason Fellman, Research Assistant Professor with ACRC, is involved with several carbon projects. His research goals are to understand how the ecology and biogeochemistry of proglacial streams may change as receding glaciers are replaced by forested ecosystems (and as glaciers contribute less meltwater to streamflow); and to determine how climate warming is affecting wetland carbon dynamics and the export of organic carbon to freshwater and coastal marine ecosytems.
Jason's current glacial stream projects include studies of atmospheric deposition and glacial organic carbon export to determine if byproducts from fossil fuel combustion are the main source of carbon within (and exported from) glacial ecosystems. He and his collaborators are also conducting a series of laboratory bioassays to determine if glacial organic carbon, which they hypothesize is mainly from deposition of fossil fuel combustion byproducts, is highly available to aquatic organisms. These laboratory bioassays are paired with a stream food web study to determine if proglacial stream food webs are sustained by old but bioavailable organic carbon released from glacial ecosystems. High resolution sampling of glacial outflow streams and watersheds of varying glacial coverage are also being conducted to assess how changes in watershed glaciation influence the cycling and exchange of organic matter between terrestrial, freshwater and coastal marine ecosystems.
Jason's current wetland carbon projects with Dave D'Amore (USFS PNW) and Eran Hood (UAS) include a soil laboratory incubation experiment to determine the potential vulnerability of wetland soil carbon stocks to projected changes in climate warming, as well as a high resolution field sampling campaign to quantify fluxes of organic and inorganic carbon to coastal marine waters. They are also planning to initiate an in situ soil manipulation experiment where they will transplant wetland soil cores along an elevational transect to determine how changes in temperature and precipitation influence soil carbon dynamics. This team is particularly focused on determining how climate change will impact organic carbon delivery to aquatic ecosystems.
Jason is also working with Brian Buma (UAS) on a project titled "Linking LIDAR and stream organic carbon export: Can aboveground biomass and landscape composition be used to predict the export and biogeochemistry of stream organic carbon?" Organic carbon (OC) export from terrestrial ecosystems is critical to the metabolic stability of freshwater and coastal marine ecosystems, as well as sustaining extremely important cultural and economic species including Pacific salmon. Linking stream OC concentration to watershed vegetation structure and composition represents an important step forward in our efforts to understand the total magnitude, variability, and vulnerability of terrestrial to aquatic C fluxes to changes in vegetation as a result of climate change. This research uses a novel approach to directly link these two realms – vegetation carbon and watershed OC export – in a spatially explicit, high resolution manner using lidar datasets, field calibrations, and stream water sampling in a pristine watershed within the temperate rainforest of SE Alaska.