Interactions among shrub cover and the soil microclimate may determine future Arctic carbon budgets

TitleInteractions among shrub cover and the soil microclimate may determine future Arctic carbon budgets
Publication TypeJournal Article
Year of Publication2012
AuthorsCahoon S.MP, Sullivan P.F, Shaver GR, Welker J.M, Post E.
JournalEcology LettersEcology LettersEcology Letters
Volume15
Pagination1415-1422
Date PublishedDec
ISBN Number1461-023X
Accession NumberISI:000310250600008
Keywordsarctic, boreal, climate change, climate-change, co2 exchange, ecosystems, er, gep, litter decomposition, nee, net co2 flux, northern alaska, plant community responses, respiration, shrub encroachment, temperature, tundra, vegetation
Abstract

Arctic and Boreal terrestrial ecosystems are important components of the climate system because they contain vast amounts of soil carbon (C). Evidence suggests that deciduous shrubs are increasing in abundance, but the implications for ecosystem C budgets remain uncertain. Using midsummer CO2 flux data from 21 sites spanning 16 degrees of latitude in the Arctic and Boreal biomes, we show that air temperature explains c. one-half of the variation in ecosystem respiration (ER) and that ER drives the pattern in net ecosystem CO2 exchange across ecosystems. Woody sites were slightly stronger C sinks compared with herbaceous communities. However, woody sites with warm soils similar to 10 similar to C) were net sources of CO2, whereas woody sites with cold soils similar to 10 similar to C) were strong sinks. Our results indicate that transition to a shrub-dominated Arctic will increase the rate of C cycling, and may lead to net C loss if soil temperatures rise.

Short TitleEcol LettEcol Lett
Alternate JournalEcol Lett