{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T20:07:51Z","timestamp":1767211671703,"version":"build-2065373602"},"reference-count":59,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2018,8,4]],"date-time":"2018-08-04T00:00:00Z","timestamp":1533340800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The soil active layer in boreal forests is sensitive to climate warming. Climate-induced changes in the active layer may greatly affect the global carbon budget and planetary climatic system by releasing large quantities of greenhouse gases that currently are stored in permafrost. Ground surface temperature is an immediate driver of active layer thickness (ALT) dynamics. In this study, we mapped ALT distribution in Chinese boreal larch forests from 2000 to 2015 by integrating remote sensing data with the Stefan equation. We then examined the changes of the ALT in response to changes in ground surface temperature and identified drivers of the spatio-temporal patterns of ALT. Active layer thickness varied from 1.18 to 1.3 m in the study area. Areas of nonforested land and low elevation or with increased air temperature had a relatively high ALT, whereas ALT was lower at relatively high elevation and with decreased air temperatures. Interannual variations of ALT had no obvious trend, however, and the ALT changed at a rate of only \u22120.01 and 0.01 m year\u22121. In a mega-fire patch of 79,000 ha burned in 2003, \u0394ALT (ALTi \u2212 ALT2002, where 2003 \u2264 i \u2264 2015) was significantly higher than in the unburned area, with the influence of the wildfire persisting 10 years. Under the high emission scenario (RCP8.5), an increase of 2.6\u20134.8 \u00b0C in mean air temperature would increase ALT into 1.46\u20131.55 m by 2100, which in turn would produce a significant positive feedback to climate warming.<\/jats:p>","DOI":"10.3390\/rs10081225","type":"journal-article","created":{"date-parts":[[2018,8,7]],"date-time":"2018-08-07T03:44:18Z","timestamp":1533613458000},"page":"1225","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Spatio-Temporal Variations of Soil Active Layer Thickness in Chinese Boreal Forests from 2000 to 2015"],"prefix":"10.3390","volume":"10","author":[{"given":"Xiongxiong","family":"Bai","sequence":"first","affiliation":[{"name":"Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2170-589X","authenticated-orcid":false,"given":"Jian","family":"Yang","sequence":"additional","affiliation":[{"name":"Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, Liaoning, China"},{"name":"Department of Forestry, University of Kentucky, Lexington, KY 40546, USA"}]},{"given":"Bo","family":"Tao","sequence":"additional","affiliation":[{"name":"Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA"}]},{"given":"Wei","family":"Ren","sequence":"additional","affiliation":[{"name":"Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA"}]}],"member":"1968","published-online":{"date-parts":[[2018,8,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1177\/0309133313478314","article-title":"The active layer: A conceptual review of monitoring, modelling techniques and changes in a warming climate","volume":"37","author":"Bonnaventure","year":"2013","journal-title":"Prog. Phys. Geogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1016\/S0921-8181(97)00009-X","article-title":"Global warming and active-layer thickness: Results from transient general circulation models","volume":"15","author":"Anisimov","year":"1997","journal-title":"Glob. Planet Chang."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/S0921-8181(01)00096-0","article-title":"Patterns of soil temperature and moisture in the active layer and upper permafrost at Barrow, Alaska 1993\u20131999","volume":"29","author":"Hinkel","year":"2001","journal-title":"Glob. Planet Chang."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1016\/S0304-3800(99)00127-1","article-title":"Analytic representation of the active layer thickness field, Kuparuk River Basin, Alaska","volume":"123","author":"Shiklomanov","year":"1999","journal-title":"Ecol. Model."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Liu, L., Schaefer, K., Zhang, T., and Wahr, J. (2012). Estimating 1992\u20132000 average active layer thickness on the Alaskan North Slope from remotely sensed surface subsidence. J. Geophys. Res. Earth Surf., 117.","DOI":"10.1029\/2011JF002041"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1002\/(SICI)1099-1530(199701)8:1<1::AID-PPP243>3.0.CO;2-U","article-title":"Thawing of the active layer on the coastal plain of the Alaskan Arctic","volume":"8","author":"Romanovsky","year":"1997","journal-title":"Permafr. Periglac. Process."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1002\/ppp.425","article-title":"Active-layer mapping at regional scales: A 13-year spatial time series for the Kuparuk region, north-central Alaska","volume":"13","author":"Shiklomanov","year":"2002","journal-title":"Permafr. Periglac. Process."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1002\/ppp.568","article-title":"Spatial distribution of ground surface temperatures and active layer depths in the H\u00f6vsg\u00f6l area, northern Mongolia","volume":"17","author":"Heggem","year":"2006","journal-title":"Permafr. Periglac. Process."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1038\/nature08031","article-title":"The effect of permafrost thaw on old carbon release and net carbon exchange from tundra","volume":"459","author":"Schuur","year":"2009","journal-title":"Nature"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1038\/480032a","article-title":"Climate change: High risk of permafrost thaw","volume":"480","author":"Schuur","year":"2011","journal-title":"Nature"},{"key":"ref_11","unstructured":"Cannone, N., Guglielmin, M., Hauck, C., and Muhll, D.V. (2003, January 21\u201325). The impact of recent glacier fluctuation and human activities on permafrost distribution, Stelvio Pass (Italian Central-Eastern Alps). Proceedings of the 8th International Conference on Permafrost, Z\u00fcrich, Switzerland."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/j.coldregions.2007.07.005","article-title":"Changes in permafrost environments along the Qinghai\u2013Tibet engineering corridor induced by anthropogenic activities and climate warming","volume":"53","author":"Jin","year":"2008","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_13","first-page":"333","article-title":"Permafrost\u2014And its effects on human activities in arctic and subarctic regions","volume":"3","year":"1979","journal-title":"GeoJournal"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1080\/10889370009377698","article-title":"The circumpolar active layer monitoring (calm) program: Research designs and initial results","volume":"24","author":"Brown","year":"2000","journal-title":"Polar Geogr."},{"key":"ref_15","unstructured":"Hoelzle, M., and Gruber, S. (2008, January 25\u201329). Borehole and ground surface temperatures and their relationship to meteorological conditions in the Swiss Alps. Proceedings of the Ninth International Conference on Permafrost, Fairbanks, Alaska."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1002\/ppp.1839","article-title":"Assessing Permafrost Degradation and Land Cover Changes (1986\u20132009) using Remote Sensing Data over Umiujaq, Sub-Arctic Qu\u00e9bec","volume":"26","author":"Beck","year":"2015","journal-title":"Permafr. Periglac. Process."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1002\/ppp.1763","article-title":"Ground Thermal Regime and Permafrost Distribution under a Changing Climate in Northern Norway","volume":"24","author":"Farbrot","year":"2013","journal-title":"Permafr. Periglac. Process."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1984","DOI":"10.1002\/2016JF003876","article-title":"Response of changes in seasonal soil freeze\/thaw state to climate change from 1950 to 2010 across china","volume":"121","author":"Peng","year":"2016","journal-title":"J. Geophys. Res. Earth Surf."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1002\/ppp.449","article-title":"A model for regional-scale estimation of temporal and spatial variability of active layer thickness and mean annual ground temperatures","volume":"14","author":"Sazonova","year":"2003","journal-title":"Permafr. Periglac. Process."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2177","DOI":"10.5194\/tc-8-2177-2014","article-title":"A new approach to mapping permafrost and change incorporating uncertainties in ground conditions and climate projections","volume":"8","author":"Zhang","year":"2014","journal-title":"Cryosphere"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1002\/(SICI)1099-1530(199732)8:2<205::AID-PPP252>3.0.CO;2-5","article-title":"A neural network method to determine the presence or absence of Permafrost near Mayo, Yukon Territory, Canada","volume":"8","author":"Leverington","year":"1997","journal-title":"Permafr. Periglac. Process."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1016\/j.rse.2006.09.004","article-title":"Temporal and spatial variability of the beginning and end of daily spring freeze\/thaw cycles derived from scatterometer data","volume":"106","author":"Bartsch","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1002\/ppp.637","article-title":"Estimating the extent of near-surface permafrost using remote sensing, Mackenzie Delta, Northwest Territories","volume":"20","author":"Nguyen","year":"2009","journal-title":"Permafr. Periglac. Process."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1002\/ppp.686","article-title":"Remote sensing and field-based mapping of permafrost distribution along the Alaska Highway corridor, interior Alaska","volume":"21","author":"Panda","year":"2010","journal-title":"Permafr. Periglac. Process."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1002\/ppp.589","article-title":"Degradation of permafrost in the Xing\u2019anling Mountains, northeastern China","volume":"18","author":"Jin","year":"2007","journal-title":"Permafr. Periglac. Process."},{"key":"ref_26","first-page":"1","article-title":"Geological evolution and age of formation of permafrost in northeastern China since the late Pleistocene","volume":"3","author":"Guo","year":"1981","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"18627","DOI":"10.1029\/94JD01024","article-title":"Satellite analysis of the severe 1987 forest fires in northern China and southeastern Siberia","volume":"99","author":"Cahoon","year":"1994","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2041","DOI":"10.1111\/j.1365-2486.2012.02649.x","article-title":"Spatial patterns and drivers of fire occurrence and its future trend under climate change in a boreal forest of Northeast China","volume":"18","author":"Liu","year":"2012","journal-title":"Glob. Chang. Biol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.geoderma.2014.02.010","article-title":"Changes in soil total organic carbon after an experimental fire in a cold temperate coniferous forest: A sequenced monitoring approach","volume":"226\u2013227","author":"Cui","year":"2014","journal-title":"Geoderma"},{"key":"ref_30","first-page":"1219","article-title":"Resilience and vulnerability of permafrost to climate change","volume":"40","author":"Jorgenson","year":"2010","journal-title":"Can. J. Earth Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.gloplacha.2008.02.001","article-title":"Cryospheric change in China","volume":"62","author":"Li","year":"2008","journal-title":"Glob. Planet Chang."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.foreco.2013.06.056","article-title":"Post-fire tree recruitment of a boreal larch forest in Northeast China","volume":"307","author":"Cai","year":"2013","journal-title":"For. Ecol. Manag."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"51","DOI":"10.5194\/tc-6-51-2012","article-title":"Comparison of MODIS-derived land surface temperatures with ground surface and air temperature measurements in continuous permafrost terrain","volume":"6","author":"Hachem","year":"2012","journal-title":"Cryosphere"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1657\/AAAR00C-13-306","article-title":"Remote Sensing of the Mean Annual Surface Temperature and Surface Frost Number for Mapping Permafrost in China","volume":"47","author":"Ran","year":"2015","journal-title":"Arct. Antarct. Alp. Res."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Yang, Y.Z., Cai, W.H., and Yang, J. (2017). Evaluation of MODIS Land Surface Temperature Data to Estimate Near-Surface Air Temperature in Northeast China. Remote Sens., 9.","DOI":"10.3390\/rs9050410"},{"key":"ref_36","unstructured":"Choi, T., and Helder, D.L. (2005, January 23\u201327). Generic sensor modeling for modulation transfer function (MTF) estimation. Proceedings of the Pecora 16 Global Priorities in Land Remote Sensing, Sioux Falls, South Dakota."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1016\/S0304-3800(02)00016-9","article-title":"Variability of seasonal thaw depth in permafrost regions: A stochastic modeling approach","volume":"153","author":"Anisimov","year":"2002","journal-title":"Ecol. Model."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1002\/ppp.1882","article-title":"Contrasting Soil Thermal Regimes in the Forest-Tundra Transition Near Nadym, West Siberia, Russia","volume":"28","author":"Matyshak","year":"2015","journal-title":"Permafr. Periglac. Process."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1002\/(SICI)1099-1530(199610)7:4<301::AID-PPP231>3.0.CO;2-R","article-title":"Permafrost monitoring and detection of climate change","volume":"7","author":"Smith","year":"1996","journal-title":"Permafr. Periglac. Process."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1002\/ppp.1849","article-title":"Eighteen Year Record of Forest Fire Effects on Ground Thermal Regimes and Permafrost in the Central Mackenzie Valley, NWT, Canada","volume":"26","author":"Smith","year":"2015","journal-title":"Permafr. Periglac. Process."},{"key":"ref_41","unstructured":"Kersten, M.S. (1949). Laboratory Research for the Determination of Thermal Properties of Soils, University of Minnesota. ACFEL Tech Rep 23."},{"key":"ref_42","first-page":"41","article-title":"Effect of Forest Fire on Soil Physical and Chemical Properties of typical Forests in Daxing\u2019an Mountains","volume":"40","author":"Zhang","year":"2012","journal-title":"J. Northeast For. Univ."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1002\/ppp.1845","article-title":"Active Layer Thickness Prediction on the Western Antarctic Peninsula","volume":"26","author":"Wilhelm","year":"2015","journal-title":"Permafr. Periglac. Process."},{"key":"ref_44","unstructured":"Core Writing Team, Pachauri, R.K., and Meyer, L.A. (2014). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, IPCC."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1007\/BF00547132","article-title":"A review of techniques for parameter sensitivity analysis of environmental models","volume":"32","author":"Hamby","year":"1994","journal-title":"Environ. Monit. Assess."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1097","DOI":"10.1111\/j.1600-0587.2010.06577.x","article-title":"The landscape similarity toolbox: New tools for optimizing the location of control sites in experimental studies","volume":"33","author":"Dilts","year":"2010","journal-title":"Ecography"},{"key":"ref_47","first-page":"723","article-title":"Application of ground penetration radar to permafrost survey in Mohe County, Heilongjiang Province","volume":"37","author":"Chen","year":"2015","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_48","first-page":"1369","article-title":"Factors affecting the thickness of permafrost\u2019s active layer in Huzhong National Nature Reserve","volume":"26","author":"Lv","year":"2007","journal-title":"Chin. J. Ecol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.rse.2012.12.008","article-title":"Satellite-derived land surface temperature: Current status and perspectives","volume":"131","author":"Li","year":"2013","journal-title":"Remote Sens. Environ."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"17937","DOI":"10.1073\/pnas.0700290104","article-title":"Impact of vegetation removal and soil aridation on diurnal temperature range in a semiarid region: Application to the Sahel","volume":"104","author":"Zhou","year":"2007","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.foreco.2018.01.017","article-title":"Intra-and inter-specific variation of the maximum size-density relationship along an aridity gradient in Iberian pinewoods","volume":"411","author":"Aguirre","year":"2018","journal-title":"For. Ecol. Manag."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1016\/S0013-7952(02)00242-9","article-title":"Engineering geological characteristics and processes of permafrost along the Qinghai\u2013Xizang (Tibet) Highway","volume":"68","author":"Wu","year":"2003","journal-title":"Eng. Geol."},{"key":"ref_53","first-page":"1","article-title":"The effect of disturbance on permafrost terrain","volume":"138","author":"Brown","year":"1969","journal-title":"Cold Reg. Res. Eng. Lab. Spec. Rep."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1002\/(SICI)1099-1530(199701)8:1<45::AID-PPP240>3.0.CO;2-K","article-title":"Effects of Climate on the Active Layer and Permafrost on the North Slope of Alaska, U.S.A","volume":"8","author":"Zhang","year":"1997","journal-title":"Permafr. Periglac. Process."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1023\/A:1005504031923","article-title":"Observational Evidence of Recent Change in the Northern High-Latitude Environment","volume":"46","author":"Serreze","year":"2000","journal-title":"Clim. Chang."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1002\/ppp.445","article-title":"Impact of the timing and duration of seasonal snow cover on the active layer and permafrost in the Alaskan Arctic","volume":"14","author":"Ling","year":"2003","journal-title":"Permafr. Periglaci. Process."},{"key":"ref_57","first-page":"110","article-title":"Spatial and temporal variability in active layer thickness over the Russian Arctic drainage basin","volume":"110","author":"Zhang","year":"2005","journal-title":"J. Geophys. Res."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1657\/AAAR00C-14-016","article-title":"Thermal Impacts of Boreal Forest Vegetation on Active Layer and Permafrost Soils in Northern da Xing\u2019Anling (Hinggan) Mountains, Northeast China","volume":"47","author":"Chang","year":"2015","journal-title":"Arct. Antarc. Alp. Res."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"733","DOI":"10.1139\/e06-121","article-title":"Climate warming and active layer thaw in the boreal and tundra environments of the Mackenzie Valley","volume":"44","author":"Woo","year":"2007","journal-title":"Can. J. Earth Sci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/8\/1225\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:16:34Z","timestamp":1760195794000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/8\/1225"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,8,4]]},"references-count":59,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2018,8]]}},"alternative-id":["rs10081225"],"URL":"https:\/\/doi.org\/10.3390\/rs10081225","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2018,8,4]]}}}