caa a22 4500 445384115 CHVBK 20180317143026.0 cr unu---uuuuu 170323e20110801xx s 000 0 eng 10.1007/s10021-011-9447-5 doi (NATIONALLICENCE)springer-10.1007/s10021-011-9447-5 The Effects of Snow, Soil Microenvironment, and Soil Organic Matter Quality on N Availability in Three Alaskan Arctic Plant Communities [Elektronische Daten] [Jennie DeMarco, Michelle Mack, M. Bret-Harte] Climate warming in The Arctic may lead to a shift from graminoid to shrub dominance, which may, in turn, alter the structure and function of the ecosystem through shrub influences on the abiotic and/or biotic controls over biogeochemical cycles of carbon (C) and nitrogen (N). In Arctic tundra, near Toolik Lake, Alaska, we quantified net N-mineralization rates under ambient and manipulated snow treatments at three different plant communities that varied in abundance of deciduous shrubs. Our objective was twofold: (1) to test whether the amount of snow that can accumulate around Arctic deciduous shrubs maintains winter soil temperatures high enough to stimulate microbial activity and increase soil N levels (effect of soil microclimate) and (2) to compare the relative effects of snow versus shrubs on N availability via effects on the main drivers of N-mineralization: SOM quality versus microclimate. Winter snow addition had a positive effect on summer, but not winter, N-mineralization rates. Soil organic matter quality had a nine times larger effect on N-mineralization than did soil microclimate in the summer season and only SOM quality had a detectable effect on N-mineralization in the winter. Here we conclude that on a short time scale, shrub interactions with snow may play a role in increasing plant available N, primarily through effects on the summer soil microenvironment. In addition, differences in SOM quality can drive larger differences in net N-mineralization than changes in soil microclimate of the magnitude of what we saw across our three sites. Springer Science+Business Media, LLC, 2011 Arctic nationallicence climate change nationallicence deciduous shrubs nationallicence net nitrogen mineralization nationallicence snow manipulation nationallicence soil organic matter nationallicence DeMarco Jennie Department of Biology, University of Florida, 220 Bartram Hall, 32611, Gainesville, Florida, USA aut Mack Michelle Department of Biology, University of Florida, 220 Bartram Hall, 32611, Gainesville, Florida, USA aut Bret-Harte M. Institute of Arctic Biology, University of Alaska, 902 N. Koyukuk Dr., 99775, Fairbanks, Alaska, USA aut Ecosystems Springer-Verlag 14/5(2011-08-01), 804-817 1432-9840 14:5<804 2011 14 10021 https://doi.org/10.1007/s10021-011-9447-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-011-9447-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- DeMarco Jennie Department of Biology, University of Florida, 220 Bartram Hall, 32611, Gainesville, Florida, USA aut NATIONALLICENCE 700 1- Mack Michelle Department of Biology, University of Florida, 220 Bartram Hall, 32611, Gainesville, Florida, USA aut NATIONALLICENCE 700 1- Bret-Harte M. Institute of Arctic Biology, University of Alaska, 902 N. Koyukuk Dr., 99775, Fairbanks, Alaska, USA aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag 14/5(2011-08-01), 804-817 1432-9840 14:5<804 2011 14 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer