Above- and below-ground plant biomass response to experimental warming in northern Alaska

作者：Hollister Robert D^*; Flaherty Kathryn J

来源：Applied Vegetation Science, 2010, 13(3): 378-387.

DOI：10.1111/j.1654-109X.2010.01079.x

• Above-ground biomass
• Below-ground biomass
• Biomass allocation
• Carex aquatilis
• Climate change
• Mycorrhizal infection
• Salix rotundifolia

Question
Does experimental warming, designed to simulate future warming of the Arctic, change the biomass allocation and mycorrhizal infection of tundra plants?
Location
High Arctic tundra near Barrow, Alaska, USA (71 degrees 18'N 156 degrees 40'W).
Methods
Above and below ground plant biomass of all species was harvested following 3-4 yr of 1-2 degrees C of experimental warming. Biomass allocation and arbuscular mycorrhizal infection were also examined in the two dominant species, Salix rotundifolia and Carex aquatilis.
Results
Above-ground biomass of graminoids increased in response to warming but there was no difference in total plant biomass or the ratio of above-ground to below-ground biomass for the community as a whole. Carex aquatilis increased above-ground biomass and proportionally allocated more biomass above ground in response to warming. Salix rotundifolia increased the amount of above- and below-ground biomass allocated per leaf in response to warming. Mycorrhizal infection rates showed no direct response to warming, but total abundance was estimated to have likely increased in response to warming owing to increased root biomass of S. rotundifolia.
Conclusions
The community as a whole was resistant to short-term warming and showed no significant changes in above- or below-ground biomass despite significant increases in above-ground biomass of graminoids. However, the patterns of biomass allocation for C. aquatilis and S. rotundifolia did change with warming. This suggests that long-term warming may result in changes in the above-ground to below-ground biomass ratio of the community.

• 出版日期2010-8