Spatial distribution of young forests and carbon fluxes within recent disturbances in Russia

• Published in: Global Change Biology
• Main Authors: Loboda, Tatiana V., Chen, Dong
• Other Authors: National Aeronautics and Space Administration's Carbon Cycle, Land Cover and Land Use Change
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: taiga
• Online Access: http://dx.doi.org/10.1111/gcb.13349; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fgcb.13349; https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcb.13349

Abstract Forest stand age plays a major role in regulating carbon fluxes in boreal and temperate ecosystems. Young boreal forests represent a relatively small but persistent source of carbon to the atmosphere over 30 years after disturbance, while temperate forests switch from a substantial source over the first 10 years to a notable sink until they reach maturity. Russian forests are the largest contiguous forest belt in the world that accounts for 17% of the global forest cover; however, despite its critical role in controlling global carbon cycle, little is known about spatial patterns of young forest distribution across Russia as a whole, particularly before the year 2000. Here, we present a map of young (0–27 years of age) forests, where 12‐ to 27‐year‐old forests were modeled from the single‐date 500 m satellite record and augmented with the 0‐ to 11‐year‐old forest map aggregated from the 30 m resolution contemporary record between 2001 and 2012. The map captures the distribution of forests with the overall accuracy exceeding 85% within three largest bioclimatic vegetation zones (northern, middle, and southern taiga), although mapping accuracy for disturbed classes was generally low (the highest of 31% for user's and producer's accuracy for the 12–27 age class and the maximum of 74% for user's and 32% for producer's accuracy for the 0–11 age class). The results show that 75.5 ± 17.6 Mha (roughly 9%) of Russian forests were younger than 30 years of age at the end of 2012. The majority of these 47 ± 4.7 Mha (62%) were distributed across the middle taiga bioclimatic zone. Based on the published estimates of net ecosystem production ( NEP ) and the produced map of young forests, this study estimates that young Russian forests represent a total sink of carbon at the rate of 1.26 Tg C yr −1 .