|Appears in Collections:||Biological and Environmental Sciences Journal Articles|
|Peer Review Status:||Refereed|
|Title:||Responses of Dryas octopetala to ITEX environmental manipulations: a synthesis with circumpolar comparisons|
|Author(s):||Welker, Jeffery M|
Parsons, Andrew N
Robinson, Clare H
|Citation:||Welker JM, Molau U, Parsons AN, Robinson CH & Wookey P (1997) Responses of Dryas octopetala to ITEX environmental manipulations: a synthesis with circumpolar comparisons. Global Change Biology, 3 (S1), pp. 61-73. https://doi.org/10.1111/j.1365-2486.1997.gcb143.x.|
|Abstract:||We have examined organismic responses of Dryas octopetala to simulated changes in the summer climate at four tundra sites as part of the International Tundra Experiment (ITEX). Our study sites are located in the High Arctic, on Svalbard, Norway, in the Low Arctic at Abisko, Sweden, and at Toolik Lake, Alaska, USA and our temperate alpine site is at Niwot Ridge, Colorado, USA. These sites represent a range of tundra temperature and precipitation regimes, being generally cold and dry in the High Arctic and warmer and wetter at Toolik Lake and Niwot Ridge. Results from our studies indicate organismic attributes such as flowering shoot length varies by 30% between low and high arctic populations and that experimental warming results in significant increases in shoot height at three of four sites. We find that phenological development of Dryas is accelerated under experimentally warmed conditions which corresponds with a lengthening of the growing season in autumn, greater degrees of seed set and a higher likelihood of colonization of bare ground. We also observe that Dryas dominated ecosystems which are exposed to experimental manipulations are capable of exhibiting net carbon sequestration in late autumn, and that Dryas photosynthesis and green leaf biomass is significantly greater under warmer as opposed to ambient temperature conditions. Dryas leaf nitrogen is also significantly lowered under warmer conditions resulting in senescent leaves having a higher C:N ratio than those under ambient conditions. Together these findings indicate that Dryas phenology and carbon flux may be altered to the greatest degree in spring and again in autumn by higher summer temperatures and that simultaneously both positive and negative feedback effects may result from changes in plant and ecosystem performance. © 1997 Blackwell Science Ltd.|
|Rights:||The publisher does not allow this work to be made publicly available in this Repository. Please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.|
|WELKER_et_al-1997-Global_Change_Biology.pdf||Fulltext - Published Version||1.02 MB||Adobe PDF||Under Permanent Embargo Request a copy|
Note: If any of the files in this item are currently embargoed, you can request a copy directly from the author by clicking the padlock icon above. However, this facility is dependent on the depositor still being contactable at their original email address.
This item is protected by original copyright
Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
If you believe that any material held in STORRE infringes copyright, please contact email@example.com providing details and we will remove the Work from public display in STORRE and investigate your claim.