| Title: |
Patterns of and controls over nitrogen inputs by green alder (Alnus viridis spp. fruticosa) to a secondary successional chronosequence in interior Alaska I - N2 Fixation and Soil Temperature
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| Contacts: |
Mitchell, Jen
Ruess, Roger
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| Abstract: |
We measured rates of nitrogen fixation by Alnus viridis spp. fruticosa and concurrent subcanopy soil temperature at BNZ LTER. To do so we utilized replicate (n=3/stage) stands of a seral sequence of successional stages maintained by the Bonanza Creek Long-Term Ecological Research program (BNZ LTER). At each of the 9 replicate stands we selected a total of 70 individual shrubs. During each of 7 sampling periods, 3 across the growing season of 1997 and 4 during 1998, we randomly selected 10 of 70 A. viridis spp. fruticosa at each replicate stand. We used acetylene reduction assays (ARA) to estimate rates of N2 fixation at each of the selected shrubs and concurrently measured soil temperature at each shrub. The attached database may be utilized to (1) elucidate seasonal trends in rates of N2 fixation by A. viridis spp. fruticosa across a boreal forest chronosequence and (2) investigate soil temperature controls over rates of N2 fixation. It may also be used to statistically analyze differences between years, successional stages and replicates within successional stage in both rates of ARA and temperature.
We developed this database to describe seasonal trends of rates of nitrogen fixation by A. viridis spp. fruticosa across a boreal forest chronosequence and to elucidate soil temperature controls over rates.
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| Keywords: |
Alder, nitrogen cycling, nitrogen fixation, secondary succession, soil temperature, |
| Categories: |
Biogeochemistry
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| Study Period: |
Jun 3, 1997 to Sep 25, 1998
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| Bounding Box: |
West longitude: -148.3599027°
North latitude: 64.7666796°
East longitude: -148.2446238°
South latitude: 64.68945831°
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| Site References: |
UP1A -- UP1A was established to follow the development of vegetation following the burning of a well developed 200 year old white spruce stand on a south facing slope. The vegetation has progressed from an herbaceous community following the fire to an open hardwood stand.
UP1B -- Young Paper Birch/Shrub/Herbaceous Stand
UP1M -- /A. viridis/ was absent in one replicate from the post-fire (UP1C) and mid-succession (UP2C) replicate stands, likely due to competition for water with a dense aspen overstory. Therefore, I substituted these stands with two additional stands where /A. viridis/ was present and which closely resembled and were near to the established BNZ LTER stands.
UP2A -- Closed Mixed White Spruce - Paper Birch Stand
UP2B -- Closed Mixed White Spruce - Paper Birch Stand
UP2M -- /A. viridis/ was absent in one replicate from the post-fire (UP1C) and mid-succession (UP2C) replicate stands, likely due to competition for water with a dense aspen overstory. Therefore, I substituted these stands with two additional stands where /A. viridis/ was present and which closely resembled and were near to the established BNZ LTER stands.
UP3A -- Mature white spruce spruce stand on a south-facing slope
UP3B -- Closed White Spruce Forest
UP3C -- Closed White Spruce Forest
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| Data Columns: |
| Column |
Name |
Units |
Type |
| 1 |
Year |
yy |
Datetime |
| 2 |
Replicate/siteID |
|
integer |
| 3 |
julian |
ddd |
Datetime |
| 4 |
treenumber |
|
integer |
| 5 |
ARA |
µmol |
float |
| 6 |
soiltemperature10cm |
Celsius |
float |
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| Data File(s): |
150_NfixSoilTemp.txt
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| Supplemental Files: |
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| Metadata Formats: |
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| Public Release: |
Nov 20, 2005
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| Publications: |
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The Bonanza Creek LTER, including this website, is supported by the
National Science Foundation through awards
DEB-0620579,
DEB-0423442,
DEB-0080609,
DEB-9810217,
DEB-9211769,
DEB-8702629
and by the USDA Forest Service, Pacific Northwest Research Station through agreement number RJVA-PNW-01-JV-11261952-231.
Any opinions, findings, conclusions, or recommendations expressed in the
material are those of the author(s) and do not necessarily reflect
the views of the supporting agencies or the program as a whole.
© Bonanza Creek LTER, 2009.
Last modified 22-Nov-09
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Disclaimer
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