Monitoring biochemical limitations to photosynthesis in N and P-limited radiata pine using plant functional traits quantified from hyperspectral imagery
Abstract
The prediction of carbon uptake by forests across fertility gradients requires accurate characterisation of how
biochemical limitations to photosynthesis respond to variation in key elements such as nitrogen (N) and
phosphorus (P). Over the last decade, proxies for chlorophyll and photosynthetic activity have been extracted
from hyperspectral imagery and used to predict important photosynthetic variables such as the maximal rate of
carboxylation (Vcmax) and electron transport (Jmax). However, little research has investigated the generality of
these relationships within the nitrogen (N) and phosphorus (P) limiting phases, which are characterised by mass
based foliage ratios of N:P ≤ 10 for N limitations and N:P > 10 for P limitations.
Using measurements obtained from one year old Pinus radiata D. Don grown under a factorial range of N and
P treatments this research examined relationships between photosynthetic capacity (Vcmax, Jmax) and measured
N, P and chlorophyll (Chla+b). Using functional traits quantified from hyperspectral imagery we then examined
the strength and generality of relationships between photosynthetic variables and Photochemical Reflectance
Index (PRI), Sun-Induced Chlorophyll Fluorescence (SIF) and chlorophyll a + b derived by radiative transfer
model inversion.
There were significant (P < .001) and strong relationships between photosynthetic variables and both N
(R2 = 0.82 for Vcmax; R2 = 0.87 for Jmax) and Chla+b (R2 = 0.85 for Vcmax; R2 = 0.86 for Jmax) within the N
limiting phase that were weak (R2 < 0.02) and insignificant within the P limiting phase. Similarly, there were
significant (P < .05) positive relationships between P and photosynthetic variables (R2 = 0.50 for Vcmax;
R2 = 0.58 for Jmax) within the P limiting phase that were insignificant and weak (R2 < 0.33) within the N
limiting phase.
Predictions of photosynthetic variables using Chla+b estimated by model inversion were significant
(P < .001), positive and strong (R2 = 0.64 for Vcmax; R2 = 0.63 for Jmax) within the N limiting phase but
insignificant and weak (R2 < 0.05) within the P limiting phase. In contrast, both SIF and PRI exhibited
moderate to strong positive correlations with photosynthetic variables within both the N and P limiting phases.
These results suggest that quantified SIF and PRI from hyperspectral images may have greater generality in
predicting biochemical limitations to photosynthesis than proxies for N and chlorophyll a + b, particularly
under high foliage N content, when P is limiting.
Materias
High resolution hyperspectralJ(max)
N:P ratio
Nutrient limitation
Physically based models
Radiative transfer
Reflectance
V-cmax
Origen
Remote Sensing of Environment 248 (2020) 11200310.1016/j.rse.2020.112003
https://repositorio.uchile.cl/handle/2250/178445
Documento no disponible en formato digital. Consultar en biblioteca INFOR: Contacto

Related items
Showing items related by title, author, creator and subject.
-
Using hyperspectral plant traits linked to photosynthetic efficiency to assess N and P partition
Watt, Michael S.; Buddenbaum, Henning; Leonardo, Ellen Mae C.; Estarija, Honey Jane C.; Bown, Horacio E.; Gómez Gallego, Mireia; Hartley, Robin; Massam, Peter; Wright, Liam; Zarco Tejada, Pablo J. (Elsevier, 2020)Spatial prediction of photosynthesis requires an understanding of how foliage nitrogen (N) and phosphorus (P) regulate this process and the relationship between these elements and scalable ... -
An air-drying model for piled logs of Eucalyptus globulus and Eucalyptus nitens in Chile
Bown Intveen, Horacio; Lasserre, Jean-Pierre (Springer, 2015)Background: Water accounts for around half of the total mass in living trees, and therefore large savings can be achieved if logs are dried before transporting or burning. Methods: An ... -
Rasgos-CL: A functional trait database of Chilean woody plants
Alfaro, Elías; Pérez Tello, Valentina; Acevedo Tapia, Manuel; Ovalle, Juan F.; Segovia, Ricardo; Craven, Dylan (Wiley, 2023)Due to language and networking barriers, global initiatives to compile trait data often fail to integrate data from sources in non-English languages or scientists that largely speak and write ...