scholarly journals Frequent sexual reproduction and high intraspecific variation inSalix arctica: Implications for a terrestrial feedback to climate change in the High Arctic

Author(s):  
Heidi Steltzer ◽  
Ruth A. Hufbauer ◽  
Jeffery M. Welker ◽  
Maxime Casalis ◽  
Patrick F. Sullivan ◽  
...  
2019 ◽  
Vol 46 (12) ◽  
pp. 6681-6689 ◽  
Author(s):  
Louise M. Farquharson ◽  
Vladimir E. Romanovsky ◽  
William L. Cable ◽  
Donald A. Walker ◽  
Steven V. Kokelj ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. J. H. Nati ◽  
M. B. S. Svendsen ◽  
S. Marras ◽  
S. S. Killen ◽  
J. F. Steffensen ◽  
...  

AbstractHow ectothermic animals will cope with global warming is a critical determinant of the ecological impacts of climate change. There has been extensive study of upper thermal tolerance limits among fish species but how intraspecific variation in tolerance may be affected by habitat characteristics and evolutionary history has not been considered. Intraspecific variation is a primary determinant of species vulnerability to climate change, with implications for global patterns of impacts of ongoing warming. Using published critical thermal maximum (CTmax) data on 203 fish species, we found that intraspecific variation in upper thermal tolerance varies according to a species’ latitude and evolutionary history. Overall, tropical species show a lower intraspecific variation in thermal tolerance than temperate species. Notably, freshwater tropical species have a lower variation in tolerance than freshwater temperate species, which implies increased vulnerability to impacts of thermal stress. The extent of variation in CTmax among fish species has a strong phylogenetic signal, which may indicate a constraint on evolvability to rising temperatures in tropical fishes. That is, in addition to living closer to their upper thermal limits, tropical species may have higher sensitivity and lower adaptability to global warming compared to temperate counterparts. This is evidence that freshwater tropical fish communities, worldwide, are especially vulnerable to ongoing climate change.


2013 ◽  
Vol 51 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Tomi P. Luoto ◽  
Stephen J. Brooks ◽  
Veli-Pekka Salonen

2009 ◽  
Vol 5 (4) ◽  
pp. 542-544 ◽  
Author(s):  
Toke Thomas Høye ◽  
Jörg U. Hammel ◽  
Thomas Fuchs ◽  
Søren Toft

Climate change is advancing the onset of the growing season and this is happening at a particularly fast rate in the High Arctic. However, in most species the relative fitness implications for males and females remain elusive. Here, we present data on 10 successive cohorts of the wolf spider Pardosa glacialis from Zackenberg in High-Arctic, northeast Greenland. We found marked inter-annual variation in adult body size (carapace width) and this variation was greater in females than in males. Earlier snowmelt during both years of its biennial maturation resulted in larger adult body sizes and a skew towards positive sexual size dimorphism (females bigger than males). These results illustrate the pervasive influence of climate on key life-history traits and indicate that male and female responses to climate should be investigated separately whenever possible.


2017 ◽  
Vol 3 (2) ◽  
pp. 378-405 ◽  
Author(s):  
J. Fouché ◽  
M. J. Lafrenière ◽  
K. Rutherford ◽  
S. Lamoureux

Arctic landscapes are experiencing intense warming and modification of precipitation regimes with climate change. Permafrost disturbances and climate change impacts on hydrology of Arctic watersheds are likely to modify the quantity and composition of exported dissolved organic matter (DOM). In July 2007, intense rainfall and active layer thickening caused widespread active layer detachments at Cape Bounty, Melville Island (Canada). This study investigates the impacts of seasonal hydrology and permafrost disturbance on DOM composition exported from High Arctic headwater catchments. In 2012, streams were sampled from three disturbed catchments and one undisturbed catchment. The composition of DOM was characterized using absorbance and fluorescence spectroscopy. DOM was mostly exported during the spring freshet. Throughout this period, the undisturbed catchment exported humified DOM with high humic-like fluorescence that likely originated from runoff through shallow organic rich soil. In contrast, DOM exported from disturbed catchments was fresher, less humified with a high proportion of low molecular weight humic acid. We demonstrate that disturbed catchments delivered likely more labile DOM derived from either thawed permafrost or enhanced microbial activity. If this labile DOM comes from an ancient pool, as indicated by other studies at this site, disturbances may strengthen the permafrost carbon feedback on climate change.


2019 ◽  
Author(s):  
Graham A. Colby ◽  
Matti O. Ruuskanen ◽  
Kyra A. St. Pierre ◽  
Vincent L. St. Louis ◽  
Alexandre J. Poulain ◽  
...  

AbstractTemperatures in the Arctic are expected to increase dramatically over the next century, yet little is known about how microbial communities and their underlying metabolic processes will be affected by these environmental changes in freshwater sedimentary systems. To address this knowledge gap, we analyzed sediments from Lake Hazen, NU Canada. Here, we exploit the spatial heterogeneity created by varying runoff regimes across the watershed of this uniquely large lake at these latitudes to test how a transition from low to high runoff, used as one proxy for climate change, affects the community structure and functional potential of dominant microbes. Based on metagenomic analyses of lake sediments along these spatial gradients, we show that increasing runoff leads to a decrease in taxonomic and functional diversity of sediment microbes. Our findings are likely to apply to other, smaller, glacierized watersheds typical of polar or high latitude / high altitudes ecosystems; we can predict that such changes will have far reaching consequences on these ecosystems by affecting nutrient biogeochemical cycling, the direction and magnitude of which are yet to be determined.


2021 ◽  
Author(s):  
Sarah Luce

Arctic wetlands have been globally important carbon reservoirs throughout the past but climate change is threatening to shift their status to carbon sources. Increasing Arctic temperatures are depleting perennial snowpacks these wetlands depend upon as their hydrological inputs which is altering their environmental conditions and carbon cycles. The objective of this study is to investigate how the physical conditions of Arctic wetlands will be altered by climate change and what influence these changes will have on CO2 exchange. High spatial and temporal resolution biophysical data from a high Arctic wetland, collected over the growing season of 2015, was used for this analysis. The results from this study indicate that the wetland is at risk of thawing and drying out under a warmer climate regime. CO2 emissions were found to increase most significantly with increased air temperatures, while CO2 uptake increased with increases in solar radiation and soil moisture. Combined, these results suggest that CO2 production in the soil will increase while CO2 uptake will decrease in Arctic wetlands as climate change continues.


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