Long-term experimental warming and nutrient additions increase productivity in tall deciduous shrub tundra
Mack, Michelle C.
Bret-Harte, M. Syndonia
Shaver, Gaius R.
MetadataShow full item record
KeywordArctic; Carbon pools; Climate change; Deciduous shrubs; Manipulated warming; Meta-analysis; Nitrogen pools; Nutrient additions; Tundra
Warming Arctic temperatures can drive changes in vegetation structure and function directly by stimulating plant growth or indirectly by stimulating microbial decomposition of organic matter and releasing more nutrients for plant uptake and growth. The arctic biome is currently increasing in deciduous shrub cover and this increase is expected to continue with climate warming. However, little is known how current deciduous shrub communities will respond to future climate induced warming and nutrient increase. We examined the plant and ecosystem response to a long-term (18 years) nutrient addition and warming experiment in an Alaskan arctic tall deciduous shrub tundra ecosystem to understand controls over plant productivity and carbon (C) and nitrogen (N) storage in shrub tundra ecosystems. In addition, we used a meta-analysis approach to compare the treatment effect size for aboveground biomass among seven long-term studies conducted across multiple plant community types within the Arctic. We found that biomass, productivity, and aboveground N pools increased with nutrient additions and warming, while species diversity decreased. Both nutrient additions and warming caused the dominant functional group, deciduous shrubs, to increase biomass and proportional C and N allocation to aboveground stems but decreased allocation to belowground stems. For all response variables except soil C and N pools, effects of nutrients plus warming were largest. Soil C and N pools were highly variable and we could not detect any response to the treatments. The biomass response to warming and fertilization in tall deciduous shrub tundra was greater than moist acidic and moist non-acidic tundra and more similar to the biomass response of wet sedge tundra. Our data suggest that in a warmer and more nutrient-rich Arctic, tall deciduous shrub tundra will have greater total deciduous shrub biomass and a higher proportion of woody tissue that has a longer residence time, with a lower proportion of C and N allocated to belowground stems.
© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosphere 5 (2014): art72, doi:10.1890/ES13-00281.1.
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Species compositional differences on different-aged glacial landscapes drive contrasting responses of tundra to nutrient addition Hobbie, Sarah E.; Gough, Laura; Shaver, Gaius R. (2005-01-17)In the northern foothills of the Brooks Range, Alaska, moist non-acidic tundra dominates more recently deglaciated upland landscapes, whereas moist acidic tundra dominates older upland landscapes. In previous studies, ...
Nutrient limitation of woody debris decomposition in a tropical forest : contrasting effects of N and P addition Chen, Yao; Sayer, Emma J.; Li, Zhian; Mo, Qifeng; Li, Yingwen; Ding, Yongzhen; Wang, Jun; Lu, Xiankai; Tang, Jianwu; Wang, Faming (2015-04)Tropical forests represent a major terrestrial store of carbon (C), a large proportion of which is contained in the soil and decaying organic matter. Woody debris plays a key role in forest C dynamics because it contains ...
Nitrogen interception and export by experimental salt marsh plots exposed to chronic nutrient addition Brin, Lindsay D.; Valiela, Ivan; Goehringer, Dale; Howes, Brian L. (Inter-Research, 2010-02-11)Mass balance studies conducted in the 1970s in Great Sippewissett Salt Marsh, New England, showed that fertilized plots intercepted 60 to 80% of the nitrogen (N) applied at several treatment levels every year from April ...