1. |
- Cornell, Sarah, et al.
(author)
-
Thresholds in the Arctic
- 2013
-
In: Arctic Resilience Interim Report 2013.. - Stockholm : Stockholm Environment Institute and Stockholm Resilience Centre. - 9789186125424 ; , s. 37-69
-
Book chapter (peer-reviewed)
|
|
2. |
|
|
3. |
|
|
4. |
|
|
5. |
|
|
6. |
- Holding, J. M., et al.
(author)
-
Experimentally determined temperature thresholds for Arctic plankton community metabolism
- 2013
-
In: Biogeosciences. - : Copernicus GmbH. - 1726-4189. ; 10:1, s. 357-370
-
Journal article (peer-reviewed)abstract
- Climate warming is especially severe in the Arctic, where the average temperature is increasing 0.4 degrees C per decade, two to three times higher than the global average rate. Furthermore, the Arctic has lost more than half of its summer ice extent since 1980 and predictions suggest that the Arctic will be ice free in the summer as early as 2050, which could increase the rate of warming. Predictions based on the metabolic theory of ecology assume that temperature increase will enhance metabolic rates and thus both the rate of primary production and respiration will increase. However, these predictions do not consider the specific metabolic balance of the communities. We tested, experimentally, the response of Arctic plankton communities to seawater temperature spanning from 1 degrees C to 10 degrees C. Two types of communities were tested, open-ocean Arctic communities from water collected in the Barents Sea and Atlantic influenced fjord communities from water collected in the Svalbard fjord system. Metabolic rates did indeed increase as suggested by metabolic theory, however these results suggest an experimental temperature threshold of 5 degrees C, beyond which the metabolism of plankton communities shifts from autotrophic to heterotrophic. This threshold is also validated by field measurements across a range of temperatures which suggested a temperature 5.4 degrees C beyond which Arctic plankton communities switch to heterotrophy. Barents Sea communities showed a much clearer threshold response to temperature manipulations than fjord communities.
|
|
7. |
|
|
8. |
- Vaquer-Sunyer, Raquel, et al.
(author)
-
Seasonal patterns in Arctic planktonic metabolism (Fram Strait - Svalbard region)
- 2013
-
In: Biogeosciences. - : Copernicus GmbH. - 1726-4189. ; 10:3, s. 1451-1469
-
Journal article (peer-reviewed)abstract
- The metabolism of the Arctic Ocean is marked by extremely pronounced seasonality and spatial heterogeneity associated with light conditions, ice cover, water masses and nutrient availability. Here we report the marine planktonic metabolic rates (net community production, gross primary production and community respiration) along three different seasons of the year, for a total of eight cruises along the western sector of the European Arctic (Fram Strait - Svalbard region) in the Arctic Ocean margin: one at the end of 2006 (fall/winter), two in 2007 (early spring and summer), two in 2008 (early spring and summer), one in 2009 (late spring-early summer), one in 2010 (spring) and one in 2011 (spring). The results show that the metabolism of the western sector of the European Arctic varies throughout the year, depending mostly on the stage of bloom and water temperature. Here we report metabolic rates for the different periods, including the spring bloom, summer and the dark period, increasing considerably the empirical basis of metabolic rates in the Arctic Ocean, and especially in the European Arctic corridor. Additionally, a rough annual metabolic estimate for this area of the Arctic Ocean was calculated, resulting in a net community production of 108 g C m(-2) yr(-1).
|
|