{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:31:30Z","timestamp":1760243490845,"version":"build-2065373602"},"reference-count":98,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2013,4,8]],"date-time":"2013-04-08T00:00:00Z","timestamp":1365379200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJGI"],"abstract":"<jats:p>Recent profound changes have been observed in the Arctic environment, including record low sea ice extents and high latitude greening. Studying the Arctic and how it is changing is an important element of climate change science. The Tundra, an ecoregion of the Arctic, is directly related to climate change due to its effects on the snow ice feedback mechanism and greenhouse gas cycling. Like all ecoregions, the Tundra border is shifting, yet studies and policies require clear delineation of boundaries. There are many options for ecoregion classification systems, as well as resources for creating custom maps. To help decision makers identify the best classification system possible, we present a review of North American Tundra ecoregion delineations and further explore the methodologies, purposes, limitations, and physical properties of five common ecoregion classification systems. We quantitatively compare the corresponding maps by area using a geographic information system.<\/jats:p>","DOI":"10.3390\/ijgi2020324","type":"journal-article","created":{"date-parts":[[2013,4,8]],"date-time":"2013-04-08T12:01:31Z","timestamp":1365422491000},"page":"324-348","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["A Comparative Review of North American Tundra Delineations"],"prefix":"10.3390","volume":"2","author":[{"given":"Kirk","family":"Silver","sequence":"first","affiliation":[{"name":"College of the Environment and Life Sciences, 106 Coastal Institute-MESM,  University of Rhode Island, Kingston, RI 02881, USA"}]},{"given":"Mark","family":"Carroll","sequence":"additional","affiliation":[{"name":"Sigma Space Corporation, Biospheric Sciences Laboratory, Code 618,  NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA"}]}],"member":"1968","published-online":{"date-parts":[[2013,4,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"87","DOI":"10.2307\/3698081","article-title":"On the origin and migrations of the greenland esquimaux","volume":"35","author":"Markham","year":"1865","journal-title":"J. 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