Abstract
Measurement of nitrogen isotopic composition (δ15N) of plants and soil nitrogen might allow the characteristics of N transformation in an ecosystem to be detected. We tested the measurement of δ15N for its ability to provide a picture of N dynamics at the ecosystem level by doing a simple comparison of δ15N between soil N pools and plants, and by using an existing model. δ15N of plants and soil N was measured together with foliar nitrate reductase activity (NRA) and the foliar NO3 - pool at two sites with different nitrification rates in a temperature forest in Japan. δ15N of plants was similar to that of soil NO3 - in the high-nitrification site. Because of high foliar NRA and the large foliar NO 3 - pool at this site, we concluded that plant δ 15N indicated a great reliance of plants on soil NO3 - there. However, many δ15N of soil N overlapped each other at the other site, and δ15N could not provide definitive evidence of the N source. The existing model was verified by measured δ15N of soil inorganic N and it explained the variations of plant δ15N between the two sites in the context of relative importance of nitrification, but more information about isotopic fractionations during plant N uptake is required for quantitative discussions about the plant N source. The model applied here can provide a basis to compare δ15N signatures from different ecosystems and to understand N dynamics.
| Original language | English |
|---|---|
| Pages (from-to) | 457-469 |
| Number of pages | 13 |
| Journal | Ecosystems |
| Volume | 6 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Aug 2003 |
| Externally published | Yes |
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Keywords
- Foliar NO
- Modeling
- Nitrate reductase activity
- Nitrogen availability
- Nitrogen dynamics
- Nitrogen isotope ratio
ASJC Scopus subject areas
- Ecology
Cite this
Natural 15N abundance of plants and soil N in a temperate coniferous forest. / Koba, Keisuke; Hirobe, Muneto; Koyama, Lina; Kohzu, Ayato; Tokuchi, Naoko; Nadelhoffer, Knute John; Wada, Eitaro; Takeda, Hiroshi.
In: Ecosystems, Vol. 6, No. 5, 08.2003, p. 457-469.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Natural 15N abundance of plants and soil N in a temperate coniferous forest
AU - Koba, Keisuke
AU - Hirobe, Muneto
AU - Koyama, Lina
AU - Kohzu, Ayato
AU - Tokuchi, Naoko
AU - Nadelhoffer, Knute John
AU - Wada, Eitaro
AU - Takeda, Hiroshi
PY - 2003/8
Y1 - 2003/8
N2 - Measurement of nitrogen isotopic composition (δ15N) of plants and soil nitrogen might allow the characteristics of N transformation in an ecosystem to be detected. We tested the measurement of δ15N for its ability to provide a picture of N dynamics at the ecosystem level by doing a simple comparison of δ15N between soil N pools and plants, and by using an existing model. δ15N of plants and soil N was measured together with foliar nitrate reductase activity (NRA) and the foliar NO3 - pool at two sites with different nitrification rates in a temperature forest in Japan. δ15N of plants was similar to that of soil NO3 - in the high-nitrification site. Because of high foliar NRA and the large foliar NO 3 - pool at this site, we concluded that plant δ 15N indicated a great reliance of plants on soil NO3 - there. However, many δ15N of soil N overlapped each other at the other site, and δ15N could not provide definitive evidence of the N source. The existing model was verified by measured δ15N of soil inorganic N and it explained the variations of plant δ15N between the two sites in the context of relative importance of nitrification, but more information about isotopic fractionations during plant N uptake is required for quantitative discussions about the plant N source. The model applied here can provide a basis to compare δ15N signatures from different ecosystems and to understand N dynamics.
AB - Measurement of nitrogen isotopic composition (δ15N) of plants and soil nitrogen might allow the characteristics of N transformation in an ecosystem to be detected. We tested the measurement of δ15N for its ability to provide a picture of N dynamics at the ecosystem level by doing a simple comparison of δ15N between soil N pools and plants, and by using an existing model. δ15N of plants and soil N was measured together with foliar nitrate reductase activity (NRA) and the foliar NO3 - pool at two sites with different nitrification rates in a temperature forest in Japan. δ15N of plants was similar to that of soil NO3 - in the high-nitrification site. Because of high foliar NRA and the large foliar NO 3 - pool at this site, we concluded that plant δ 15N indicated a great reliance of plants on soil NO3 - there. However, many δ15N of soil N overlapped each other at the other site, and δ15N could not provide definitive evidence of the N source. The existing model was verified by measured δ15N of soil inorganic N and it explained the variations of plant δ15N between the two sites in the context of relative importance of nitrification, but more information about isotopic fractionations during plant N uptake is required for quantitative discussions about the plant N source. The model applied here can provide a basis to compare δ15N signatures from different ecosystems and to understand N dynamics.
KW - Foliar NO
KW - Modeling
KW - Nitrate reductase activity
KW - Nitrogen availability
KW - Nitrogen dynamics
KW - Nitrogen isotope ratio
UR - http://www.scopus.com/inward/record.url?scp=0141457232&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0141457232&partnerID=8YFLogxK
U2 - 10.1007/s10021-002-0132-6
DO - 10.1007/s10021-002-0132-6
M3 - Article
VL - 6
SP - 457
EP - 469
JO - Ecosystems
JF - Ecosystems
SN - 1432-9840
IS - 5
ER -