Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability

TY - JOUR

T1 - Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability

AU - Craine, J M

AU - Elmore, A J

AU - Aidar, M P M

AU - Bustamante, M

AU - Dawson, T

AU - Hobbie, E A

AU - Kahmen, A

AU - Mack, M C

AU - McLauchlan, K K

AU - Michelsen, Anders

AU - Nardoto, G B

AU - Pardo, L H

AU - Penuelas, J

AU - Reich, P B

AU - Schuur, E A G

AU - Stock, W D

AU - Templer, P H

AU - Virginia, R A

AU - Welker, J M

AU - Wright, I J

N1 - KEYWORDS climate • isotopes • mycorrhizal fungi • nitrogen • nitrogen availability

PY - 2009

Y1 - 2009

N2 - Ratios of nitrogen (N) isotopes in leaves could elucidate underlying patterns of N cycling across ecological gradients. To better understand global-scale patterns of N cycling, we compiled data on foliar N isotope ratios (d15N), foliar N concentrations, mycorrhizal type and climate for over 11 000 plants worldwide. Arbuscular mycorrhizal, ectomycorrhizal, and ericoid mycorrhizal plants were depleted in foliar d15N by 2‰, 3.2‰, 5.9‰, respectively, relative to nonmycorrhizal plants. Foliar d15N increased with decreasing mean annual precipitation and with increasing mean annual temperature (MAT) across sites with MAT = -0.5°C, but was invariant with MAT across sites with MAT < -0.5°C. In independent landscape-level to regional-level studies, foliar d15N increased with increasing N availability; at the global scale, foliar d15N increased with increasing foliar N concentrations and decreasing foliar phosphorus (P) concentrations. Together, these results suggest that warm, dry ecosystems have the highest N availability, while plants with high N concentrations, on average, occupy sites with higher N availability than plants with low N concentrations. Global-scale comparisons of other components of the N cycle are still required for better mechanistic understanding of the determinants of variation in foliar d15N and ultimately global patterns in N cycling.

AB - Ratios of nitrogen (N) isotopes in leaves could elucidate underlying patterns of N cycling across ecological gradients. To better understand global-scale patterns of N cycling, we compiled data on foliar N isotope ratios (d15N), foliar N concentrations, mycorrhizal type and climate for over 11 000 plants worldwide. Arbuscular mycorrhizal, ectomycorrhizal, and ericoid mycorrhizal plants were depleted in foliar d15N by 2‰, 3.2‰, 5.9‰, respectively, relative to nonmycorrhizal plants. Foliar d15N increased with decreasing mean annual precipitation and with increasing mean annual temperature (MAT) across sites with MAT = -0.5°C, but was invariant with MAT across sites with MAT < -0.5°C. In independent landscape-level to regional-level studies, foliar d15N increased with increasing N availability; at the global scale, foliar d15N increased with increasing foliar N concentrations and decreasing foliar phosphorus (P) concentrations. Together, these results suggest that warm, dry ecosystems have the highest N availability, while plants with high N concentrations, on average, occupy sites with higher N availability than plants with low N concentrations. Global-scale comparisons of other components of the N cycle are still required for better mechanistic understanding of the determinants of variation in foliar d15N and ultimately global patterns in N cycling.

KW - Faculty of Science

KW - planter

KW - økologi

KW - svampe

KW - mykologi

KW - kvælstof

KW - isotop

KW - plants

KW - ecology

KW - fungi

KW - mycology

KW - nitrogen

KW - isotope

U2 - 10.1111/j.1469-8137.2009.02917.x

DO - 10.1111/j.1469-8137.2009.02917.x

M3 - Journal article

C2 - 19563444

SN - 0028-646X

VL - 183

SP - 980

EP - 992

JO - New Phytologist

JF - New Phytologist

IS - 4

ER -