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Diversification of Nitrogen Sources in Various Tundra Vegetation Types in the High Arctic.

Skrzypek G, Wojtuń B, Richter D, Jakubas D, Wojczulanis-Jakubas K, Samecka-Cymerman A - PLoS ONE (2015)

Bottom Line: The percentage of the total tundra N-pool provided by birds, ranged from 0-21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra.The stable nitrogen isotope mixing mass balance, in contrast to direct methods that measure actual deposition, indicates the ratio between the actual N-loads acquired by plants from different N-sources.Our results enhance our understanding of the importance of different N-sources in the Arctic tundra and the used methodological approach can be applied elsewhere.

View Article: PubMed Central - PubMed

Affiliation: West Australian Biogeochemistry Centre, School of Plant Biology, The University of Western Australia, Crawley, Western Australia, Australia.

ABSTRACT
Low nitrogen availability in the high Arctic represents a major constraint for plant growth, which limits the tundra capacity for carbon retention and determines tundra vegetation types. The limited terrestrial nitrogen (N) pool in the tundra is augmented significantly by nesting seabirds, such as the planktivorous Little Auk (Alle alle). Therefore, N delivered by these birds may significantly influence the N cycling in the tundra locally and the carbon budget more globally. Moreover, should these birds experience substantial negative environmental pressure associated with climate change, this will adversely influence the tundra N-budget. Hence, assessment of bird-originated N-input to the tundra is important for understanding biological cycles in polar regions. This study analyzed the stable nitrogen composition of the three main N-sources in the High Arctic and in numerous plants that access different N-pools in ten tundra vegetation types in an experimental catchment in Hornsund (Svalbard). The percentage of the total tundra N-pool provided by birds, ranged from 0-21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra. The total N-pool utilized by tundra plants in the studied catchment was built in 36% by birds, 38% by atmospheric deposition, and 26% by atmospheric N2-fixation. The stable nitrogen isotope mixing mass balance, in contrast to direct methods that measure actual deposition, indicates the ratio between the actual N-loads acquired by plants from different N-sources. Our results enhance our understanding of the importance of different N-sources in the Arctic tundra and the used methodological approach can be applied elsewhere.

No MeSH data available.


Related in: MedlinePlus

Distribution of different tundra vegetation types in the Fuglebekken catchment, Hornsund, Svalbard (77°00’N 15°30’E) based on orthoimage [25].For tundra division details refer to Table 1.
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pone.0136536.g001: Distribution of different tundra vegetation types in the Fuglebekken catchment, Hornsund, Svalbard (77°00’N 15°30’E) based on orthoimage [25].For tundra division details refer to Table 1.

Mentions: The study was carried out in the Wedel Jarlsberg Land (77°00’N 15°30’E), within an unglaciated Fuglebekken catchment in the central part of the Fuglebergsletta abrasion-accumulation plain on the northern shore of Hornsund fjord in SW Spitsbergen, Svalbard (Fig 1, [25]). The climate on Spitsbergen is a polar and marine type. The annual mean air temperature in sampling year 2011 was –2.6°C, and was above the 30-year mean (-4.2°C for 1979–2010). The total annual precipitation in 2011 of 617 mm was significantly higher than the long-term annual mean (453 mm, 1979–2010). The period with air temperatures over 0°C is very short; therefore, the growing season is no longer than four months (June–September) (Figure A in S1 File). The thawing period usually begins in early June and ranges from 68 to 135 days, with an average of 92 days [26].


Diversification of Nitrogen Sources in Various Tundra Vegetation Types in the High Arctic.

Skrzypek G, Wojtuń B, Richter D, Jakubas D, Wojczulanis-Jakubas K, Samecka-Cymerman A - PLoS ONE (2015)

Distribution of different tundra vegetation types in the Fuglebekken catchment, Hornsund, Svalbard (77°00’N 15°30’E) based on orthoimage [25].For tundra division details refer to Table 1.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4574312&req=5

pone.0136536.g001: Distribution of different tundra vegetation types in the Fuglebekken catchment, Hornsund, Svalbard (77°00’N 15°30’E) based on orthoimage [25].For tundra division details refer to Table 1.
Mentions: The study was carried out in the Wedel Jarlsberg Land (77°00’N 15°30’E), within an unglaciated Fuglebekken catchment in the central part of the Fuglebergsletta abrasion-accumulation plain on the northern shore of Hornsund fjord in SW Spitsbergen, Svalbard (Fig 1, [25]). The climate on Spitsbergen is a polar and marine type. The annual mean air temperature in sampling year 2011 was –2.6°C, and was above the 30-year mean (-4.2°C for 1979–2010). The total annual precipitation in 2011 of 617 mm was significantly higher than the long-term annual mean (453 mm, 1979–2010). The period with air temperatures over 0°C is very short; therefore, the growing season is no longer than four months (June–September) (Figure A in S1 File). The thawing period usually begins in early June and ranges from 68 to 135 days, with an average of 92 days [26].

Bottom Line: The percentage of the total tundra N-pool provided by birds, ranged from 0-21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra.The stable nitrogen isotope mixing mass balance, in contrast to direct methods that measure actual deposition, indicates the ratio between the actual N-loads acquired by plants from different N-sources.Our results enhance our understanding of the importance of different N-sources in the Arctic tundra and the used methodological approach can be applied elsewhere.

View Article: PubMed Central - PubMed

Affiliation: West Australian Biogeochemistry Centre, School of Plant Biology, The University of Western Australia, Crawley, Western Australia, Australia.

ABSTRACT
Low nitrogen availability in the high Arctic represents a major constraint for plant growth, which limits the tundra capacity for carbon retention and determines tundra vegetation types. The limited terrestrial nitrogen (N) pool in the tundra is augmented significantly by nesting seabirds, such as the planktivorous Little Auk (Alle alle). Therefore, N delivered by these birds may significantly influence the N cycling in the tundra locally and the carbon budget more globally. Moreover, should these birds experience substantial negative environmental pressure associated with climate change, this will adversely influence the tundra N-budget. Hence, assessment of bird-originated N-input to the tundra is important for understanding biological cycles in polar regions. This study analyzed the stable nitrogen composition of the three main N-sources in the High Arctic and in numerous plants that access different N-pools in ten tundra vegetation types in an experimental catchment in Hornsund (Svalbard). The percentage of the total tundra N-pool provided by birds, ranged from 0-21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra. The total N-pool utilized by tundra plants in the studied catchment was built in 36% by birds, 38% by atmospheric deposition, and 26% by atmospheric N2-fixation. The stable nitrogen isotope mixing mass balance, in contrast to direct methods that measure actual deposition, indicates the ratio between the actual N-loads acquired by plants from different N-sources. Our results enhance our understanding of the importance of different N-sources in the Arctic tundra and the used methodological approach can be applied elsewhere.

No MeSH data available.


Related in: MedlinePlus