<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Helbig, M</style></author><author><style face="normal" font="default" size="100%">Chasmer, L</style></author><author><style face="normal" font="default" size="100%">Kljun, N.</style></author><author><style face="normal" font="default" size="100%">Quinton, W.</style></author><author><style face="normal" font="default" size="100%">Treat, C.</style></author><author><style face="normal" font="default" size="100%">O. Sonnentag</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The positive net radiative greenhouse gas forcing of increasing methane emissions from a thawing boreal forest-wetland landscape</style></title><secondary-title><style face="normal" font="default" size="100%">Global Change Biology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2016</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://onlinelibrary.wiley.com/doi/10.1111/gcb.13520/full</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span&gt;At the southern margin of permafrost in North America, climate change causes widespread permafrost thaw. In boreal lowlands, thawing forested permafrost peat plateaus (‘forest’) lead to expansion of permafrost-free wetlands (‘wetland’). Expanding wetland area with saturated and warmer organic soils is expected to increase landscape methane (CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;) emissions. Here, we quantify the thaw-induced increase in CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;emissions for a boreal forest-wetland landscape in the southern Taiga Plains, Canada, and evaluate its impact on net radiative forcing relative to potential long-term net carbon dioxide (CO&lt;/span&gt;&lt;span&gt;2&lt;/span&gt;&lt;span&gt;) exchange. Using nested wetland and landscape eddy covariance net CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;flux measurements in combination with flux footprint modeling, we find that landscape CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;emissions increase with increasing wetland-to-forest ratio. Landscape CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;emissions are most sensitive to this ratio during peak emission periods, when wetland soils are up to 10&amp;nbsp;°C warmer than forest soils. The cumulative growing season (May–October) wetland CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;emission of ~13&amp;nbsp;g CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;m&lt;/span&gt;&lt;span&gt;−2&lt;/span&gt;&lt;span&gt;&amp;nbsp;is the dominating contribution to the landscape CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;emission of ~7&amp;nbsp;g CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;m&lt;/span&gt;&lt;span&gt;−2&lt;/span&gt;&lt;span&gt;. In contrast, forest contributions to landscape CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;emissions appear to be negligible. The rapid wetland expansion of 0.26&amp;nbsp;±&amp;nbsp;0.05% yr&lt;/span&gt;&lt;span&gt;−1&lt;/span&gt;&lt;span&gt;&amp;nbsp;in this region causes an estimated growing season increase of 0.034&amp;nbsp;±&amp;nbsp;0.007&amp;nbsp;g CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;m&lt;/span&gt;&lt;span&gt;−2&lt;/span&gt;&lt;span&gt;&amp;nbsp;yr&lt;/span&gt;&lt;span&gt;−1&lt;/span&gt;&lt;span&gt;&amp;nbsp;in landscape CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;emissions. A long-term net CO&lt;/span&gt;&lt;span&gt;2&lt;/span&gt;&lt;span&gt;&amp;nbsp;uptake of &amp;gt;200&amp;nbsp;g CO&lt;/span&gt;&lt;span&gt;2&lt;/span&gt;&lt;span&gt;&amp;nbsp;m&lt;/span&gt;&lt;span&gt;−2&lt;/span&gt;&lt;span&gt;&amp;nbsp;yr&lt;/span&gt;&lt;span&gt;−1&lt;/span&gt;&lt;span&gt;&amp;nbsp;is required to offset the positive radiative forcing of increasing CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;emissions until the end of the 21st century as indicated by an atmospheric CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;and CO&lt;/span&gt;&lt;span&gt;2&lt;/span&gt;&lt;span&gt;concentration model. However, long-term apparent carbon accumulation rates in similar boreal forest-wetland landscapes and eddy covariance landscape net CO&lt;/span&gt;&lt;span&gt;2&lt;/span&gt;&lt;span&gt;&amp;nbsp;flux measurements suggest a long-term net CO&lt;/span&gt;&lt;span&gt;2&lt;/span&gt;&lt;span&gt;&amp;nbsp;uptake between 49 and 157&amp;nbsp;g CO&lt;/span&gt;&lt;span&gt;2&lt;/span&gt;&lt;span&gt;&amp;nbsp;m&lt;/span&gt;&lt;span&gt;−2&lt;/span&gt;&lt;span&gt;&amp;nbsp;yr&lt;/span&gt;&lt;span&gt;−1&lt;/span&gt;&lt;span&gt;. Thus, thaw-induced CH&lt;/span&gt;&lt;span&gt;4&lt;/span&gt;&lt;span&gt;&amp;nbsp;emission increases likely exert a positive net radiative greenhouse gas forcing through the 21st century.&lt;/span&gt;&lt;/p&gt;</style></abstract></record></records></xml>