Response of Crops to a Heat Wave Detected by using Airborne Reflectance and Chlorophyll Fluorescence Measurements

Transcription

1 Response of Crops to a Heat Wave Detected by using Airborne Reflectance and Chlorophyll Fluorescence Measurements Peiqi Yang, Christiaan van der Tol, Wouter Verhoef, Alexander Damm, Anke Schickling and Uwe Rascher 15-Feb-2017

2 Introduction June 30 th 26 o C in 2015 July 2 nd 34 o C in 2015 HyPlant 1. rapeseed, 2. corn, 3. barley 4. wheat Day 2 Day 1 Reflectance Fluorescence

3 Introduction The Sun Reflectance Observer Fluorescence canopy soil R reveals canopy greenness (LAI, Cab), except photosynthetic reflectance index (PRI).

4 1. reflection 3. absorption 2. transmission 1. reflection 3. absorption 2. transmission

5 F reveals photosynthetic functioning, but is superimposed by canopy structure, leaf biochemical, biophysical properties and sun-observer geometry. Remote Sensing of Fluorescence, Photosynthesis and Vegetation Status ESA-ESRIN, Jan 2017

6 The Sun

7 Method Level 1. Fluorescence, reflectance indices (remote sensing products): SIF - ifld method Level 2. Leaf properties and canopy structure (SCOPE inversion) Numerical optimization Photosynthetic efficiency Heat dissipation Canopy structure LAI and leaf pigment concentration are assumed not changing between the two days. Level 3. Functional traits: fluorescence emission efficiency (SCOPE forward) SCOPE

8 Results 34 o C Fluorescence at two wavelength 687 nm and 760 nm 26 o C

9 Results Reflectance indices EVI and PRI

10 Results Leaf water content (Cw) and average leaf angles (ALA)

11 Results Vegetation optical contribution to the fluorescence observations

12 Results Fluorescence efficiency estimated from the measurements

13 Results Different responses of C3 and C4 crops + refers to an increase - refers to a decrease From PRI

14 Results Relative contribution of leaf inclination (LIDF), leaf water content (Cw), solar zenith angle, soil background to the changes in reflectance before and during the heat wave.

15 Results Relative contribution of vegetation optical properties and photosynthetic functional to the changes in fluorescence before and during the heat wave. Other includes the incoming light, solar angles.

16 Combination of R and F enables the remote detection of vegetation optical and photosynthesis functional response to environment conditions.

17

18 Thank you!!!

19 Meteorological data

20 Sampling

21 Reflectance

22 Model inversion Cost function

23 Model inversion

24

25 Compared with photosynthesis model

26 The Sun Observer Reflectance Fluorescence canopy soil Remote Sensing of Fluorescence, Photosynthesis and Vegetation Status ESA-ESRIN, Jan 2017

27 Remote Sensing of Fluorescence, Photosynthesis and Vegetation Status ESA-ESRIN, Jan 2017

28 Introduction June 30 th 26 C in2015 July 2 nd 34 C in rapeseed, 2. corn, 3. barley 4. wheat How did the crops respond to the heat wave? Using reflectance and chlorophyll fluorescence.

29 1. reflection 3. absorption 2. transmission Remote Sensing of Fluorescence, Photosynthesis and Vegetation Status ESA-ESRIN, Jan 2017

30 1. reflection 3. absorption 2. transmission Remote Sensing of Fluorescence, Photosynthesis and Vegetation Status ESA-ESRIN, Jan 2017

31 Photosynthesis Fluorescence Heat Remote Sensing of Fluorescence, Photosynthesis and Vegetation Status ESA-ESRIN, Jan 2017

32 The Sun Observer canopy soil

33 The Sun Observer Observer canopy canopy soil soil Photosynthesis Fluorescence Heat