The effects of a changing climate on root respiration of woody plants in sugar maple forests and northern peatlands

摘要: Climate change will potentially impact C cycling in terrestrial ecosystems during the next century. Plant respiration uses a significant portion of CO2 fixed photosynthesis, and predicted warmer future temperatures could result an exponential increase plant respiration, increasing amount photosynthate returned to atmosphere as new CO2, decreasing sequestered biomass. One way may counteract this loss is through metabolic acclimation, physiological downregulation at increased temperature. This study examined root experimentally warmed sugar maple dominated northern hardwood forest Upper Peninsula Michigan, United States. The objective was determine if fine roots these trees had capacity acclimate soil (+4 °C) minimize from ecosystem. conducted 2009-2011, included pre-treatment period May 2009 June 2010, with initiation treatments late summer 2010 continuing throughout growing season 2011. Root measured biweekly season, both ambient temperature for sample date reference 18°C. found no inherent differences between any treatment 15 plots. Part experimental design consisted additional heat water (ambient +30%), intended maintain adequate moisture content heated experiencing evaporative demand. + allowed us assess whether apparent acclimation due warming or simply reduction associated drier conditions. During we down-regulation (respiration rate 18°C temperature) plots receiving treatment. Much conditions caused by heating, but when effects were accounted for, there still indicating slight degree acclimation. combined dry resulted average being 6 26% greater, respectively, than control, which far less 48% that would have simple occurred 4°C